JPWO2018232451A5 - - Google Patents

Description

Cross-reference to related applications This application claims the priority of Australian Provisional Patent Application No. 2017902355 filed June 20, 2017, which is to be understood that its contents are incorporated herein by this reference.

The present invention generally relates to a process for producing a work structure from a cold spray deposit of powder, and related equipment. The present invention is particularly applicable for producing titanium and titanium alloy funnel structures, and it is convenient to disclose the present invention in connection with exemplary applications thereof below. However, it should be understood that the present invention should not be limited to this application and may be applicable to cold spray deposits such as some metals, metal / metal alloys, metal matrix composites and the like.

The following discussion of the background to the present invention is intended to facilitate understanding of the present invention. However, this discussion does not acknowledge or acknowledge that any of the materials referred to were part of the general knowledge that was published, known, or was common on the priority date of this application. Please understand.

Wrout material is a material that has been "worked" from a common cast material or from a material that has undergone additional manufacturing processes to improve properties such as ductility. The funnel material is usually free of internal and external defects such as shrinkage and porosity, which are common problems in casting, and is inherently stronger at high temperatures in cast form across grades of funnel . Ultrastructure plays a major role in material properties, and surface topography also plays a role in its practicality and longevity. This is because the smooth surface of the funnel metal or alloy helps to avoid the focus of corrosion development, for example, due to molten salts or carbon deposits.

Common industrial methods for making funnel materials include hot hydrostatic compression or pressure (HIP), which includes the mechanical properties of a wide variety of materials such as titanium, steel, aluminum, and superalloys. It is an established process that improves workability. The HIP process involves sealing the article formed in the pressurizing chamber and applying hydrostatic pressure and high temperature into the pressurizing chamber for a selected period of time, for example, 950 ° C., 100 MPa for 4 hours. including. The chamber is generally pressurized by heating the inert gas in the pressurized chamber. Therefore, HIP provides a multi-directional pressure applied over the entire outer surface of the article to be processed. This process can be used to reduce or eliminate voids in the casting and solidify the encapsulated powder to produce a sufficiently dense material. In addition, the gas trapped during the casting period or the trapped gas that appears as small pressurized bubbles produced as a result of additional manufacturing processes can be removed. Thus, the HIP process can be used to transform the microstructure into a funnel structure.

Many metals, including titanium and titanium alloys, can also be made here by methods using additional manufacturing such as cold spraying techniques. In the cold spraying process, small particles in a solid state are accelerated at high speed (usually 500 m / s or higher) in an ultrasonic gas jet and deposited on the substrate material. The kinetic energy of the particles is utilized to achieve bonding through plastic deformation in the event of collision with the substrate. The absence of oxidation allows cold spraying techniques to be used for near-net shaping of molded titanium products from powder.

Solid spray deposition components can be formed through progressive deposition of layers in the desired spray pattern. See, for example, Applicant's International Patent Publication No. WO2015157816. However, the formation of low porous solid shapes formed using conventional cold spraying methods facilitates the heating requirements of the accelerating gas required to achieve high speeds, and the formation of low porous deposits. May have formation and structural problems due to the essential thermal softening of the particles. For example, the formation of a cold spray titanium alloy with low porosity typically requires the cold spray gas to be preheated to the range of 700-1100 ° C. This inevitably results in significant heat transfer to the cold spray deposit each time the cold spray gas jet moves over the cold spray deposit to spray the cold spray particles onto the cold spray deposit. Is brought about. The heating creates thermal stress in the large deposits that can cause cracks or separation of the deposits from the substrate, even if cold spraying is still in progress. If the surface temperature is high enough, even oxidation can occur.

Efforts have been made to adopt this technique in additional manufacturing techniques, given the successful use of HIP to form funnel structures from cast materials. For example, Blose, R.M. E. Et al., "New opportunities to use alloy process for alloying additive features to titanium alloys." Metal Powerer Report 61.9 (2006) in a Metal Power Report 6-37 (2006), a report of Metal Power Report 61.9 (2006). It describes the heat treatment and application of HIP to the particle coating. Brose found that heat treatment alone was not effective in reducing porosity. However, metallographic analysis showed that the density of all coatings was close to 100 percent (regardless of initial porosity) after HIP. It was also found that the microstructure of the HIPed sample was obtained by casting and was the same as the funnel -deformed and recrystallized material. A further example is taught in US Pat. No. 6,905,728, where cold gas dynamic spraying process particles are cold sprayed onto the blades or blades of a turbine, the portion of which is vacuum sintered and after the vacuum sintering step. It teaches how to be subjected to a HIP process and heat treated after performing a HIP step.

However, these methods still have some drawbacks. In Metallurgical and Materials Transitions A, Vol 47/5, 1939-1946, Tammas-Williams observed that large tunnel-like defects could appear after HIP. The inventor himself also observed that when HIP was used, the trapped gas could coalesce and form a large gas pocket in the core of the material. See, for example, FIG. 1 (C). In addition, HIP is an energy intensive, costly and time consuming batch process. HIP uses high pressures and temperatures that are dangerous and may require specialized equipment.

International Publication No. 2015/157816 US Pat. No. 6,905,728 US Pat. No. 5,302,414 International Publication No. 2009/1090116 International Publication No. 2011/017752

Blose, R.M. E. Et al. "New opportunities to use alloy process for applying advanced features to titanium alloys." Metal Power Report 61.9 (2006): 30-37. Tammas-Williams Metallurgy and Metallurgy Transitions A, Vol 47/5, 1939-1946

Therefore, it is desirable to provide new and / or alternative methods for producing funnel structures from materials obtained by cold spraying.

The present invention provides methods and devices for the additional production of funnel structures obtained from cold sprayed particle deposits.

A first aspect of the invention provides a process of producing a product having a funnel structure, wherein the process is:
In order to convert the hardened particle structure into a funnel structure, it includes the step of applying heat and compressive load simultaneously to the application area of the cold spray deposition preform having the hardened particle structure.
A compressive load is applied laterally to the application area and
The application of compressive loads and heat to the application area raises the temperature of the preform material in the application area between the recrystallization temperature and the melting point of the material.

The process of the present invention is a funnel structure of a metal, metal alloy, or metal composite through the simultaneous application of heat and load / pressure to the cold spray deposited preform after the cold spray preform has been formed. Allows the formation of the product of. The selective and simultaneous application of heat and laterally applied compressive loads allows the cold sprayed structure of porous solidified particles to be rapidly recrystallized into a funnel structure.

The simultaneous application of lateral load and heat to the application area of the preform causes structural deformation (recrystallization) of the solidified cold spray particle structure into the funnel structure in the preform. Although not desired to be limited by any one theory, the applied heat raises the local temperature of the preform material in the application area above the recrystallization temperature of the material but below the melting point of the material. It is conceivable that sufficient temperature energy will be provided. Therefore, the crystal grains of the crystal structure of the cold spray deposited material are replaced by a new set of crystal grains that nucleate and grow in the crystal structure of the material. The compressive lateral load acts on the two front surfaces and contributes to the elimination of porosity, while at the same time initiating the work hardening required by dynamic and static recrystallization. In this sense, the applied compression lateral load can compress the structure at that temperature to remove any pores and voids in the structure / microstructure. A denser funnel structure / funnel ultrastructure is provided. As can be seen, the size of the newly formed grains / crystals defines the final mechanical properties of the material.

It should be appreciated that the load is applied laterally to the application area rather than in multiple directions, as described, for example, in the background art of the present invention, as applied in the prior art HIP process. The present invention therefore uses a compression process that results in lateral compression in the application zone, for example using compression stamps or rollers. By comparison, HIP is an energy intensive, costly, time consuming and cumbersome batch process. HIP is limited to containing materials in containers and processing structures that are only certain geometries or sizes as a result of the need to apply pressure in multiple directions. Will be done. The present invention aims to avoid these drawbacks and preferably provides a continuous process. It should be understood that the lateral application of a compressive load indicates that the direction in which the compressive load is applied to the application area is lateral to the plane of the application area. In most cases, the compressive load direction (load application direction) is approximately perpendicular to the plane of the application area. On a curved surface, its compressive load direction (load application direction) is substantially perpendicular to the tangent plane of the application area or point.

It should be understood that a cold spray deposit preform is a preform formed using cold spray deposits. This type of preform has a hardened particle structure and typically comprises a hardened cold spray lamella structure. Such cold-sprayed and hardened particle structures are "lentil-like" features from hardened or agglomerated particles that accumulate on top of each other to build the preform into the desired shape and composition. It is formed from the deformation of particles that collide on the substrate. In general, cold spray lamella structures provide high strength with limited ductility.

The preform can be provided in any desired form. However, the present invention is advantageously configured to process elongated bodies. In some embodiments, the preform is an elongated body, such as, but not limited to, strips, sheets, wires, bars, bars, and the like. Accordingly, the present invention allows the treatment of elongated and long wires and tubes to transform the microstructure of those preforms into funnel structures.

It should also be understood that the funnel structure or funnel ultrastructure, if any, is a structure containing a limited number of cast dendritic elements. Preferably, the microstructure has an equiaxed grain structure.

In the present invention, a material having a funnel structure (formed as a recrystallized structure) is made without melting the material, i.e. via a non-melting pathway. In this sense, a cold-sprayed and hardened particle structure is formed from solid particles. The deposited preform is rapidly recrystallized into a funnel structure below the melting point of the material. No state conversion occurs during the cold spray process or compressive load, making the process a solid state process. The material is therefore in a solid state below the melting point of the material, from the raw material to the finished funnel structure product. In some processes, the final funnel structure can be produced directly from the powder. Accordingly, the present invention provides new and alternative methods for producing a wide range of industrial products along with rolled products such as strips, bars, pipes, sheets, and wires. Therefore, the process has a much smaller carbon footprint and is safer and more efficient to operate than current methods compared to traditional melting and forming metallurgical processes.

Oxidation, nitriding, decarburization, and arbitrary decomposition are generally avoided in this process. The use of non-melting processes also allows oxygen-sensitive materials such as titanium and tantalum to be produced in funnel form quickly and at a much lower cost. For example, a high-strength, high-ductility Ti funnel structure can be produced from crushed Ti sponge as a powder without the costly melting process that occurs in a controlled atmosphere. Similar advantages can be applied to materials that are sensitive to phase transformations and solidification processes.

The present invention also overcomes the limitations of other additional manufacturing techniques that inherently have a melting process. For example, the preform formation of the present invention advantageously retains a nearly uniform microstructure throughout and is free of macroscopic detachment and other melting-related defects in the ingot. This is because the constituent powder particles do not melt in the cold spray process.

Heat can be applied to the application area using several suitable techniques. In some embodiments, heat is applied using conduction, induction, resistance, or thermal heating. However, the heating technique is preferably a rapid heating technique. In embodiments, this rapid heating is achieved through the application of heat by at least one of current, induction heating, or laser heating. Each of these heating methods rapidly heats the application area and rapidly raises the local temperature of the preform material in the application area above the recrystallization temperature of the material but below the melting point of the material. Make it possible. Rapid heating inevitably raises the local temperature rapidly, typically at 100 ° C./s or higher, preferably 200 ° C./s or higher, more preferably 500 ° C./s or higher. Accompanying. "Rapid" is high locality in the application area compared to several hours using alternative techniques such as HIP (HIP can take 1-2 hours to exceed 1000 ° C). It should be understood that it means reaching a certain temperature within a few seconds. The use of rapid heating techniques helps avoid oxidation of the material during the process. In addition, the rapid heating combined with the simultaneous application of compressive loads allows the funnel / microstructure of the preform to be rapidly formed in the solid state process. Preforms can therefore be rapidly transformed into a funnel structure compared to conventional processes such as HIP, facilitating process expansion and, if desired, continuous processes. In a typical example, heat is applied to the application area using current-based means. The current can be applied as alternating current or direct current. When direct current is used, the current preferably includes pulsed direct current. The current can be applied in various duty cycles. For example, the duty cycle for AC or DC power may be 10% to 100%. Similarly, the current can have various pulse frequencies. For example, the pulse frequency for AC or DC power may be 0 Hz to 500 Hz.

When heat is applied to the application area as an electric current, the application heats the material in the application area through the resistant heating of the material. The optimum current applied to the preform therefore depends on the material. Similarly, the optimum load applied to the application area depends on the mechanical and physical properties of the formed preform. Their properties depend on the properties (porous and density) of the constituent materials and the cold spray deposited material forming the preform, as well as the thickness of the preform. The applied current and compressive load can therefore fall within a wide range of values depending on the properties of the material and the preform formed. In the embodiment, the current density of the applied current is 500 to 2000 A / mm ² , preferably 800 to 1500 A / mm ² , and more preferably 1000 to 1100 A / mm ² . The voltage associated with the applied current is preferably 2-3 volts. In the embodiment, the applied compressive load is 10 to 100 kg / m ² , preferably 20 to 60 kg / m ² .

It should be understood that the load and heat applied to the sample for recrystallization, the rolling speed of the rollers, and the deposition rate of the cold spray material are influential parameters in the process of the present invention. In addition, the compression load application system, preferably the feed rate through the rollers, is typically synchronized with the rate at which the preform is made via the cold spray system.

The application of compressive loads and heat to the application zone raises the local temperature of the preform material in the application zone between the recrystallization temperature and the melting point of the material. The local temperature at which the material should be heated is, of course, material specific and depends on the material's recrystallization temperature and melting point. In embodiments, the local temperature is between 35% and 85% of the melting point of the material, preferably between 40% and 60% of the melting point of the material, and even more preferably 45% and 55% of the melting point of the material. Between. In some embodiments, the local temperature is about 50% of the melting point of the material. Also, its local temperature should be between the recrystallization temperature of the material and its melting point. For example, the local temperature range for Ti (melting point of about 1600 ° C.) and its alloys is approximately 500-800 ° C., and for Ta with a melting point of 3017 ° C., the typical local temperature is approximately. For Al having a melting point of 1500 ° C. and a melting point of 660 ° C., a typical local temperature may be up to 570 ° C.

The rate at which the deposited material passes through the rollers is also important because it is related to the rate at which the material is deposited for the continuous production of funnel structures. In embodiments, the preform supply rate from the deposition step to the load and current application step is 1-10 mm / s, preferably 1-5 mm / s, more preferably about 2 mm / s. In embodiments, the deposition rate of the cold spray material is 1-10 mm / s, preferably 1-5 mm / s, more preferably about 2 mm / s. It should be understood that for a certain height of material, the cold spray rate is preferably synchronized with the supply rate of the processing system. Cold spraying can result in a much higher deposition rate, about 15 kg / hr or 4 g / s, so deposition may be higher if necessary. In this embodiment, this continuous coupling of deposition as the preform moves through the processing system, followed by lateral compressive loading and rapid application of heat, is one of the advantages of the present invention. That is, the very rapid continuous processing of the material eliminates the need for a two-step process (as seen in current manufacturing processes) consisting of an initial cold spray deposition step followed by HIP. This is to enable.

Compressed lateral loads and heat can be applied simultaneously to the preform using several different equipment and arrangement configurations. In embodiments, the compressive load is applied laterally using at least one roller configured to compressally engage the preform. A single roller can be used with respect to the engaging surface, while it is preferred to use at least two rollers to which preform is supplied and compressed in between. At least one roller in this arrangement configuration is preferably configured to apply heat to the preform, preferably in the form of an electric current. One or more rollers are configured to pass an electric current through the preform and generate "heat" while applying a load to convert the lamella structure into a funnel structure. To achieve this, at least a portion of the rollers may be equipped with a conductive material.

It should be appreciated that the rollers can be formed from any suitable material that allows the selected pressure and heat to be applied to the cold sprayed preform supplied to engage with the rollers. Preferably, the roller material is selected to achieve high conductivity and wear resistance. Suitable materials include copper and copper alloys, steel, aluminum and aluminum alloys, inconel, tungsten and the like.

In some embodiments, the at least one roller comprises a cooling system or cooling device. This allows control of the heat applied to the material and avoids runaway reactions and melting. The cooling system may include any suitable cooling system such as freezing, water cooling, convection cooling, conductive cooling and the like.

The cold spray deposition preform is preferably formed in the forming step prior to the step of simultaneously applying heat and compressive loads to the application area of the preform. In the embodiment, the step is
To additionally construct the structure in the desired configuration, it involves the step of forming a preform with a solidified particle structure using cold spray deposition.

In some embodiments, the invention thus provides a process for producing a product having a funnel structure.
With the steps of forming a preform with a solidified particle structure using cold spray deposition to additionally construct the structure in the desired configuration,
In order to convert the hardened particle structure into a funnel structure, the preform application area includes a step of applying heat and compressive load at the same time.
A compressive load is applied laterally to the application area and
The application of compressive loads and heat to the application area raises the temperature of the preform material in the application area between the recrystallization temperature and the melting point of the material.

The preform can be cold sprayed onto any suitable surface prior to being subjected to heating and compression lateral loads. Preforms are typically formed on or around the feed axis on which the preform travels during the process. The feed shaft can be aligned with a surface, such as a sedimentary surface, by depositing material on the sedimentary surface to form a preform. In some embodiments, the sedimentary surface can form the surface of one of the rollers. In such an embodiment, the preform is formed on at least one surface of the rollers before being compressed by the rollers.

Preforms are formed using cold spray deposition. In embodiments, the steps to form are
Steps to use a cold spray giver to deposit cold spray material on or around the supply axis to form a product deposit surface, and
With the step of continuously depositing the material on each upper product deposition surface, using cold spray deposition to form a continuous deposition phase of the material.
A step of moving at least one of the cold atomizers or preforms axially with respect to each other along the supply axis.
Thereby including steps to form a preform of the selected length.

It should also be understood that the term "upper product sedimentation surface" is the sedimentary surface of the outermost or newest sedimentary layer of the preform product, which is axially closest to the cold sprayer. Once the cold atomizer or preform is moved, the cold atomizer is used again to deposit the cold spray material on the deposition surface and product deposition on or around the supply shaft. It should also be understood that a surface is formed and then the material is continuously deposited on each upper product deposit surface to form a continuous preform. These steps are repeated for a desired length of time until the desired length is obtained, or in the case of a continuous process, until the instrument is shut down, and so on.

The preform is preferably formed as a continuous element, typically in the form of an elongated body.

The present invention produces preform products on or around the deposition axis. The preforms formed from the process of the present invention are therefore strips, bars, wires, sheets, slabs, discs, rods, poles, staffs, wands, cylinders, columns, masts, shafts, dowels. It can (but should not be limited to) at least one of (dowel) and the like. In embodiments, the preform is formed as strips, sheets, wires, bars, or bars. In some embodiments, the preform comprises a bar. A bar is understood to have a length longer than its width / diameter, eg, at least twice its width / diameter. Wide width or diameter preforms can be produced according to the invention and are limited only by the size of the available device. In other embodiments, the preform is hollow or comprises one or more voids. In a preferred embodiment, the process is used to produce wires or rods.

Similarly, the invention preferably produces a product on or around the deposition axis. The product formed from the process of the present invention is therefore at least one of strips, bars, wires, sheets, slabs, discs, rods, poles, canes, thin canes, cylinders, columns, masts, shafts, dowels and the like. Can be provided (but should not be limited to these). In embodiments, the product is formed as strips, sheets, wires, bars, or bars. In some embodiments, the product comprises wires, rods, or strips. If the product is a wire, the wire may have a diameter of less than 10 mm, preferably less than 5 mm, more preferably less than 4 mm.

The process of the present invention allows the direct conversion of titanium powder to a metal body with a funnel structure. Therefore, with the advent of cheap titanium powder, the process of the present invention can provide economically attractive options for making primary rolled products such as wires, bars, or bars.

In some embodiments, the preform and / or product has a constant diameter along the length of the preform / product. In other embodiments, the preform and / or product is formed with a variable or non-constant diameter along the length of the preform. Preforms and products with non-constant diameters include cones, cones, stairs or tapered shapes (large to small diameters) and the like. In one embodiment, the diameter varies in a constant manner over or along the length of the preform and / or product.

The process of the present invention preferably comprises a continuous manufacturing process. The present inventor considers that "continuous addition manufacturing of funnel material" is a new function introduced by the present invention that can realize cost effective manufacturing options in many industries. To aid in continuous production, thermal and compressive lateral loads are preferably applied to the preform application area immediately after the formation of the preform application area by cold spray deposition. In embodiments, if the preform is elongated, thermal and compressive lateral loads are applied to the preform portion immediately after, preferably immediately after the portion is formed by cold spray deposition. If individual preforms are formed, thermal and compressive lateral loads are preferably applied to the preforms immediately after the formation of the preforms by cold spray deposition.

However, in other embodiments, the process can be carried out in at least two separate steps, in which the preform is formed using a cold spray deposition process (as described above) and then It should then be understood that in the second step, thermal and compressive lateral loads are applied to the preform. In these embodiments, the preform can be formed on any suitable substrate and then transported to the second step using any suitable means. In one embodiment, the preform is formed on materials with different coefficients of thermal expansion (eg, a Ti preform is formed on a steel substrate) and the difference in thermal expansion is either a heating or cooling technique. The preform used and formed is separated from the substrate. In the second step, heat and compression lateral loads can be applied to the preform to convert the cold spray microstructure into a funnel microstructure. Compressed lateral loads and heat can be applied to preforms formed using various methods as discussed above.

The cold spray deposition preform can include any suitable material, preferably any suitable metal or alloy thereof. It should be appreciated that the cold spray deposition preform can contain at least one of Al, Cu, Zn, Ni, Ti, Ta, Mg, Sc, Fe, steel and alloys thereof. In some embodiments, the cold spray deposition preform can include metal matrix composites such as carbides and metal-ceramic mixtures such as superconductors (for high wear resistant applications). In some embodiments, the material comprises at least one of Ti, Cu, Al, Fe, Sc, Ni, Mg, Ta or an alloy thereof. An example of the target metal alloy is a Ti-6Al-4V alloy. This material is preferably produced as a preform using the process of the invention.

In some embodiments, the cold spray deposit preform is formed from a cold spray deposit material containing a mixture of at least two different powders. In some embodiments, the material comprises ceramic or glass. In other embodiments, a preform consisting of a composite of at least two different metals or a mixture of at least one metal and at least one ceramic can be made. For example, a blend of two or more different powders, or composite particles (particles of more than one material) can be used as raw materials. The process is novel and can only be obtained from the present invention by mixing different powder materials to achieve unique physical and mechanical properties, such as superconductor and semiconductor applications. Allows the creation of funnel materials.

In some embodiments, the composition of the cold spray deposition preform can vary along the length of the preform. This allows flexibility in terms of product characteristics. For example, metal preforms such as bars or rods with different welding properties at the opposite shaft ends can be produced by varying the composition between the different ends. Alternatively, if a change in the properties of the preform (eg, the coefficient of thermal expansion) is desired along the length of the preform, the composition of the preform can be changed accordingly. Thus, the preform can be provided with individual lengths of different materials, or the composition of the preform can be gradually varied along the length of the preform, or the preform has these arrangement configurations. Can be provided with a combination of.

If the preform is manufactured from multiple materials, the compatibility of different materials must be considered. If at some point (eg, coherence / bonding) two or more of the proposed materials do not fit, it is necessary to separate the incompatible materials with mutually compatible materials in one or more areas. In some cases. Alternatively, in order to alleviate some incompatibility problem between the materials used, the preform can be manufactured such that there is a gradual change in composition from one material to the next.

Any suitable particle / powder can be used with the process of the invention. The powders / particles used, and their properties, will typically be selected to suit the desired properties, composition, and / or economic aspects of the particular preform product. Typically, the size of the particles imparted by cold spraying is 5 to 45 microns and has an average particle size of 15 to 30 microns. However, it should be understood that particle size may vary depending on the source and specifications of the powder used. Similarly, larger particles can be used in some applications, for example, particle sizes up to about 150 microns. One of ordinary skill in the art will be able to determine the optimum particle size or particle size distribution to use based on the morphology of the powder and the nature of the preform formed. Particles suitable for use in the present invention are commercially available.

It should be understood that the average size of cold-sprayed particles is likely to affect the density of layered deposits resulting from the material, and thus the density of the preforms formed. Preferably, the deposits are of uniform density. In some embodiments, the preform comprises pores that are generally of the same size as the sprayed particles. The pores are preferably of uniform concentration over the preform.

A second aspect of the invention provides a preform of a funnel structure formed from a process according to the first aspect of the invention.

A third aspect of the present invention is
A compression load applyer configured to simultaneously apply heat and compression load to the application area of the cold spray deposition preform, with a compression load applyer in which the compression load is applied laterally to the application area. ,
In use, compressive loads and heat application to the application area raise the temperature of the preform material in the application area between the recrystallization temperature and the melting point of the material, producing a product with a funnel structure. A device for generating is provided.

A third aspect of the present invention is
It is configured to simultaneously apply heat and compressive loads to the application area of the cold spray deposition preform in order to raise the temperature of the preform material in the application area between the recrystallization temperature of the material and the melting point. It is also possible to provide an apparatus for producing a product having a funnel structure, which comprises a compressive load applyer in which a compressive load is applied laterally to an application area.

Heat can be applied to the application area using several suitable techniques. However, the heating technique is preferably the rapid heating technique previously discussed in connection with the first aspect of the invention. In embodiments, this rapid heating is achieved through the application of heat by at least one of current, induction heating, or laser heating. In a typical example, heat is applied to the application area using current-based means. The current can be applied as alternating current or direct current. When direct current is used, the current preferably includes pulsed direct current. The current can be applied in various duty cycles. For example, the duty cycle for AC or DC power may be 10% to 100%. Similarly, the current can have various pulse frequencies. For example, the pulse frequency for AC or DC power may be 0 Hz to 500 Hz.

The optimum load applied depends on the mechanical and physical properties of the formed preform. In the embodiment, the applied compressive load is 10 to 100 kg / m ² , preferably 20 to 60 kg / m ² .

When heat is applied to the application area as a current, the optimum current applied to the preform depends on the material. The applied current and compressive load can therefore fall within a wide range of values depending on the properties of the material and the preform formed. In the embodiment, the current density of the applied current is 500 to 2000 A / mm ² , preferably 800 to 1500 A / mm ² , and more preferably 1000 to 1100 A / mm ² . The voltage associated with the applied current is preferably 2-3 volts.

As discussed above in connection with the first aspect of the invention, compressive lateral loads and heat can be applied simultaneously to the preform using several different devices and arrangement configurations. In embodiments, compressive lateral loads and heat are applied laterally using at least one roller configured to compressally engage the preform. A single roller can be used with respect to the engaging surface, while it is preferred to use at least two rollers to which preform is supplied and compressed in between. At least one roller in this arrangement configuration is preferably configured to apply heat to the preform, preferably in the form of an electric current. One or more rollers are configured to pass an electric current through the preform and generate "heat" while applying a load to convert the lamella structure into a funnel structure. To achieve this, at least a portion of the rollers may be equipped with a conductive material.

It should be appreciated that the rollers can be formed from any suitable material that allows the selected pressure and current to be applied to the cold sprayed preform supplied to engage with the rollers. Preferably, the roller material is selected to achieve high conductivity and wear resistance. Preferred materials include Cu and Cu alloys, stainless steel, Al and Al alloys, Ni alloys such as Ni and Inconel, tungsten (W), Mg, Sc and the like.

In some embodiments, the at least one roller comprises a cooling system or cooling device. This allows control of the heat applied to the material and avoids runaway reactions and melting. The cooling system may include any suitable cooling system such as freezing, water cooling, convection cooling, conductive cooling and the like.

The device preferably further comprises a cold spray depositing device for forming a cold spray depositing preform on the sedimentary surface. Therefore, the cold spray deposition preform can be formed shortly before use of the compressive load applyer. In an embodiment, the device for producing a product having a funnel structure is
A cold spray depositor for forming preforms on sedimentary surfaces with a solidified particle structure,
Thermal and compressive loads on the preform application area formed using a cold spray depositor to raise the temperature of the preform material in the application area between the material recrystallization temperature and the melting point. It is possible to provide a compression load applyer configured to simultaneously apply the compression load, and the compression load is applied laterally to the application area.

Also, the preform is preferably formed on or around the supply axis on which the preform moves during the process. The preform can be formed on a sedimentary surface aligned along the feed axis. In some embodiments, the sedimentary surface comprises at least one of the rollers. In some embodiments, the preform is formed on at least one surface of the rollers before being compressed by the rollers.

The cold spraying device used in the present invention is likely to be conventional, such devices are commercially available or individually constructed. In general, it should be understood that the basis of the equipment used for cold spraying is incorporated herein by this reference, as described in US Pat. No. 5,302,414. Illustrated. Several commercially available cold spray devices are available. It should be appreciated that the present invention is not limited to one or any type of cold spray system or equipment and can be implemented using a wide variety of cold spray systems and equipment.

Cold spraying equipment typically includes a cold spraying device in the form of a cold spray gun with a nozzle. The nozzle typically includes an outlet opening through which the deposited material is sprayed, and the nozzle directs the deposited material to be sprayed in the desired direction. In use, the nozzles are preferably aligned approximately or parallel to the axis of rotation of the preform during the period of travel.

The operating parameters for the cold spraying process can be manipulated to achieve a preform with the desired properties (density, surface finish, etc.). Therefore, parameters such as temperature, pressure, standoff (distance between the cold spray nozzle and the surface of the starting substrate to be coated), powder feed rate, and relative movement of the starting substrate and the cold spray nozzle are required. It can be adjusted according to. In general, the smaller the particle size and distribution, the denser the layers formed on the surface of the starting substrate. Fits cold spray equipment used to allow the use of higher pressures and higher temperatures, to achieve faster particle velocities and higher density microstructures, or to allow preheating of particles. It may be appropriate to let them do it.

The deposition pattern and the associated movement of the cold atomizer also affect the morphology of the sedimentary layer of the material. The deposition pattern and the associated movement of the atomizer are therefore also preferably controlled. In some embodiments, the controlled motion comprises a linear circulatory motion between at least two points.

A fourth aspect of the invention provides a method according to the first aspect of the invention, which is formed using the apparatus according to the third aspect of the invention.

It should be understood that the present invention has applications in several areas including:
-An alternative process for forming rolled products such as rods, steel pieces, wires, plates, strips, nuts, bolts, sheets, etc., which are formed with a funnel structure.
-Cold spraying, thermal spraying, welding, roller fabrication, automotive manufacturing, marine industry, mining, cable and wire manufacturing, biomedical applications, aerospace.
-Insitu heat of mixed powders-electrical, heat-electronic circuits and superconductivity through the rapid creation of new microstructures with certain electronic properties through non-melting deposition combined with mechanical treatment.
-Rapid repair and refurbishment of parts caused by corrosion and wear.

The present invention will be described herein with reference to the figures in the accompanying drawings. The accompanying drawings illustrate certain preferred embodiments of the invention.

(A) hardened particles (thin plate) of cold spray material preform, (B) hardened particles of cold spray material preform subjected to heat and compression according to the present invention to form a funnel material, (C) FIG. 6 is a schematic diagram showing solidified particles of a cold spray material preform that has undergone HIP treatment to form a funnel material. (A) SEM micrograph showing the microstructure of the etched cold spray formed from the stacking of Ti lamellae of cold sprayed and hardened particles on an aluminum substrate, (B) etched and commercially available. It is an SEM micrograph showing the etching (commercially pure- "CP") Ti microstructure. Other metals having a funnel microstructure, such as Cu, stainless steel, and Al, achieve similar equiaxed grain structures. (A) Schematic of a first embodiment of an apparatus for continuously producing funnel -structured metal strips directly from powder using cold spray non-melting deposits, (b) using a combination of load and current. It is a schematic diagram which shows how the cold spray thin plate structure is converted into a funnel structure. The application area (or reaction zone) between the rollers is magnified to show how the conversion from the lamella structure to the funnel structure occurs. (A) is a schematic of a second embodiment of a two-step apparatus for producing funnel -structured metal strips directly from powder using cold spray non-melting deposits, wherein (A) forms a preform strip. It is a figure which shows the 1st step, (B) is a figure which shows the 2nd step of forming a funnel material. (A) Illustrated microstructure of cold spray Ti strips exposed to high current and load polished prior to chemical etching, (b) revealing recrystallized and densified zones. It is a diagram illustrating the microstructure of a cold spray Ti strip exposed to high currents and loads, polished and etched to achieve. It is a figure which illustrates the microstructure corresponding to the densified zone in FIG. 4 (b) which was polished and etched. It is a figure which illustrates the microstructure of the Ti-6Al-4V alloy which was polished and etched and remains cold-sprayed. FIG. 3 provides a high magnification microstructure of a polished (rounded ) cold spray Ti- 6Al -4V alloy that has been polished and etched. FIG. 5 illustrates the microstructure of a polished, etched, cold-sprayed Ti strip. Polished and etched to reveal recrystallized and densified zones, exposed to high current and load, run 2 produced cold spray Ti strip microstructure ( roth ). It is a figure which illustrates. Polished and etched to reveal recrystallized and densified zones, exposed to high current and load, run 3 produced cold spray Ti strip microstructure ( roth ). It is a figure which illustrates. Polished and etched to reveal recrystallized and densified zones, exposed to high currents and loads, and produced in Run 4, the microstructure ( roof ) of the cold spray Ti strips. It is a figure which illustrates. (A) SEM micrograph showing the microstructure of cold spray, formed from the stacking of Ni lamellae of cold-sprayed and hardened particles (not yet copper) , and (B) cold. SEM micrographs showing the microstructure of an etched, cold-sprayed cold-sprayed particle formed from a stack of Cu thin plates of pre -sprayed and hardened particles (C) cold-sprayed and hardened particles. FIG. 3 is an SEM micrograph showing the microstructure of an etched, cold spray formed from a stack of Al thin plates (not yet roasted ).

The present invention provides a process of forming preforms such as discs, bars, bars, cones, etc. of materials using cold spraying techniques. In the present invention, the product has a funnel structure (known as a "recrystallized" structure) and is made through a non-melting pathway. In this sense, the raw solid powder material is a particle structure that is deposited, cold sprayed and hardened, which is then rapidly recrystallized into a funnel structure. This solid powder conversion process does not include a melting step. In embodiments, the material can be formed into the final funnel structural material by a continuous process starting from the solid powder feed material.

Cold spraying is a known process that has been used to apply coatings to surfaces. In general, the process is a step of feeding (metal and / or non-metal) particles to a high pressure gas flow flow that then passes through a convergent / divergent nozzle, or the neck of the nozzle, accelerating the gas flow to ultrasonic velocity. Includes a subsequent step of feeding particles to the ultrasonic gas stream. The particles are then directed to the surface to be deposited. The process is performed at a relatively low temperature below the melting point of the substrate and the deposited particles, resulting in the formation of a coating as a result of the particles hitting the surface of the substrate. The process is carried out at a relatively low temperature, thereby allowing thermodynamic, thermal, and / or chemical effects on the surface to be coated, reducing or avoiding the particles that make up the coating. do. This is a phase transformation in which the original structure and properties of the particles may otherwise be associated with high temperature coating processes such as plasma, HVOF, arc, gas flame spraying, or other thermal spraying processes. It means that it can be saved. The principles, devices, and methods underlying cold spraying are described, for example, in US Pat. No. 5,302,414, whose contents are to be understood as incorporated herein by this reference.

In the present invention, the cold spray technique is used to additionally construct a solidified particle preform structure on or around the supply shaft, which is then subjected to thermal and lateral load /. Processed using simultaneous application of pressure to form a funnel structure along the feed axis.

Preforms are aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), titanium (Ti), tantalum (Ta), steel, magnesium (Mg), scandium (Sc), iron (Fe). , And can include cold spray deposit materials selected from at least one of their alloys. In some embodiments, the cold spray deposit material can include metal matrix composites such as carbides and metal-ceramic mixtures such as superconductors (for high wear resistant applications). However, the present invention is particularly applicable to Ti, Cu, steel, and Al and their alloys.

To achieve continuous deposition of particles, cold spraying devices 110 and 110A (FIGS. 3 and 3A) preferably switch powder dispensers during the operating period when one feeder runs out of powder. Includes at least two powder feeders (not shown) that enable.

The hardened particle preform structure has "lentil" -like features from the hardened particles that accumulate on top of each other in order to build the preform into the desired shape and composition as shown in FIG. 2 (A). Formed from the deformation of cold-sprayed particles 112 colliding on a substrate to make (in the illustrated embodiment, the lower roller 120 in FIG. 3). FIG. 2A illustrates the etched, cold spray microstructure formed from the stacking of Ti lamellae on an aluminum substrate. One lentil-shaped thin plate 50 is highlighted in the microstructure. Other metals such as Cu, stainless steel, etc. have similar cold spray microstructures. In general, cold spray slab structures provide high strength with low ductility and may contain voids between the slabs in the structure, the size and extent of which depends to some extent on the gas used. , The structure is made porous to some extent. See, for example, the cold spray microstructure shown in FIGS. 6, 8 and 12, showing voids.

Following the deposition, the application area of the additionally constructed preform (eg, titanium strip) is subjected to a combination of compressive load and heat (causing heating of the application area) and a cold spray lamella structure (FIG. 2). (A)) is converted into a high-density funnel structure (FIG. 2B). As shown in FIG. 2B, the funnel structure of this material has an equiaxed grain structure. The funnel structure of Al, Cu, Zn, Ni, Ta, Mg, Sc, Fe, steel, or alloys thereof shows a similar equiaxed crystal structure. Rohto structural materials have excellent mechanical properties such as high ductility that enable the production of a wide range of industrial products such as wires, cables, rods, steel pieces, sheets and the like.

The compressive load can be applied to the preform using various device configurations. In some embodiments, the compressive load is applied using a press with a compressive element. However, the process is a continuous process in which cold spray-formed preforms are continuously fed through or under a compressive load carrier to rapidly transform the sedimentary material preform structure into a funnel structure. It is advantageous to include.

Within the device, compressive loads are applied laterally to the application area rather than multidirectionally or universally across the entire surface area, as applied in a hot hydrostatic compression (HIP) process. I want you to understand. The HIP comprises a step of sealing the article formed in the pressure chamber and a selected step of applying pressure and temperature to eliminate porosity. The HIP therefore applies pressure to the material from all directions. Applying pressure (load) to the cold spray structure from all directions means that almost equal pressure increases in the cold spray material through a pressure medium that counteracts the pressure applied to the surface of the material. Due to the interconnected porosity that allows, the loss of porosity is severely limited. This jeopardizes the removal of porosity in cold spray structures using HIP. Pressurizing, heating, and cooling the HIP chamber is a time-consuming, energy-intensive, and costly process.

The present invention applies a lateral load to the cold spray structure, allowing for complete and rapid removal of porosity, as presented in the example.

A schematic comparison of the various microstructures produced from the present invention and HIP is provided in FIG. As shown in the figure, the solidified particles (thin plate-shaped particles 30) of the cold spray material form a structure having remarkable porosity (FIG. 1 (A)). The present invention forms a funnel material having an equiaxed grain structure 35 with minimal porosity or defects to no porosity or defects (FIG. 1B). In comparison, the HIP funnel material also has an equiaxed grain structure 40, but is a coalesced material (as described in the background art) as indicated by the voids 45 in the structure of FIG. 1 (C). It may still contain defects and voids from the trapped gas that may form large gas pockets in the core of the.

The heat applied can be applied to the application area using several suitable techniques. In embodiments, heat is applied to the application area by at least one of current, induction heating, or laser heating. As mentioned earlier, each of these heating methods rapidly heats the application area to bring the local temperature of the preform material in the application area above the recrystallization temperature of the material but to the melting point of the material. Allows it to rise further down and thus avoid oxidation during its process period. The use of rapid heating techniques helps avoid oxidation of the material during the process. This is because it significantly reduces the amount of time that oxidation and oxidative invasion can occur during the recrystallization period. Thus, the preform can be rapidly converted to a funnel structure as compared to previous processes such as HIP.

In a typical example, heat is applied to the application area using current-based means. The current can be applied as alternating current or direct current. When direct current is used, the current preferably includes pulsed direct current. The current can be applied in various duty cycles. For example, the duty cycle for AC or DC power may be 10% to 100%. Similarly, the current can have various pulse frequencies. For example, the pulse frequency for AC or DC power may be 0 Hz to 500 Hz.

The application of compressive loads and heat to the application zone raises the local temperature of the preform material in the application zone between the recrystallization temperature and the melting point of the material. The temperature of the material is, of course, specific to the material and depends on the recrystallization temperature and melting point of the material. In embodiments, the temperature is between 35% and 85% of the melting point of the material, preferably between 40% and 60% of the melting point of the material, and even more preferably between 45% and 55% of the melting point of the material. be. In some embodiments, the temperature is about 50% of the melting point of the material.

For example, the temperature range for Ti (melting point of about 1600 ° C.) and its alloys is approximately 500-800 ° C. Without wishing to be limited by any one theory, the inventor noted that at these temperatures Ti is softened under a lateral load applied. However, it should be understood that the interaction between heat (applied current) and load to transform the material adds complexity to the nature of the structural transformation. This allows for varying loads and temperatures to adjust material properties to achieve higher strength by reducing the size of crystals formed during the insitu recrystallization process. (For example, the load can be increased to reduce the temperature).

An example of an embodiment of a process and apparatus 100 according to the present invention is illustrated in FIG. The device 100 uses cold spray non-melting deposits to continuously produce elongated preform strips directly from the powder. In that process, the cold spray device 110 deposits a large number of cold spray particles 112 on one roller of a pair of rollers 120, as described above, by depositing a large number of cold spray particles 112, for example, an elongated pre, such as a titanium strip. Metal strips are deposited as foam 115 to form a solidified particle structure to construct the preform 115. The preform 115 passes through opposing sets of rotating rollers 120 for simultaneous compression lateral loading, deformation, and heating. The roller 120 rotates in the direction R (the upper roller and the lower roller rotate in opposite directions), through which the preform 115 is moved in the supply direction F. The rollers 120 engage the application areas 125 of the preform 115 that are engaged between the rollers 120 and apply or flow current through the application areas 125 while applying a compressive lateral load there. Generates "heat" (eg, resistant heating) to convert the lamella structure (in the preform 115) into the funnel structure 130 without melting. The current is provided by a current source 131, a generator, a power source and the like. As shown in FIG. 2A, the compressive lateral load is applied using a pneumatic load device 132, i.e., a pneumatic piston that laterally moves the rollers 120. However, it should be understood that other compression devices can be used equally to achieve this result. The compressive load of the rollers 120 is applied laterally to the application area compressed between the rollers 120 and laterally to the supply direction F of the preform through the rollers 120. By compressive lateral loading and application of heat (in the illustrated embodiment, heat is applied using an electric current), the material is brought to a local temperature above the recrystallization temperature of the material but below the melting point of the material. To heat. Therefore, it is possible to recrystallize the crystal structure of the material, and the application of a compressive lateral load also compresses any voids in the pores inherent in the cold sprayed sheet steel structure during the softening process. help. In FIG. 3B, the application zone 125 (or reaction zone) between the rollers 120 is shown in FIG. 2B from a lamella structure (eg, as shown in FIG. 2A). Enlarged to show how the conversion to the funnel structure occurs (such as). Here, the structure 115 including the cold spray thin plates having porosity between the thin plates receives a lateral (or uniaxial) load and current in the application area 125 to form a high-density funnel recrystallization structure 130. do. Nucleation and growth of newly recrystallized grains occur in the application zone 125 or under loads and currents immediately after the application zone 125.

In the illustrated embodiment, the deposition of preform 115 occurs on the surface of one of the pairs of rollers 120. However, in other arrangement configurations, the preform may be deposited on another deposit surface, for example, the material may be deposited linearly on a plane, or, for example, the contents of each of them may be booked by reference above. Described in International Patent Publication No. WO2015157816 (cylindrical preform), International Patent Publication No. WO2009109016 (hollow pipe), or International Patent Publication No. WO2011017752 (hollow pipe), which should be understood to be incorporated herein. As such, it should be understood that it can be deposited on a starting substrate that is rotated to form a cylindrical bar, pipe, or pipe.

In the illustrated embodiment, the applied current heats the material in the application area through the resistant heating of the material. The optimum current applied to the preform 115 therefore depends on the material. Similarly, the optimum load applied will depend on the mechanical, electrical, and physical properties of the preform 115 being formed. Their properties depend on the properties (porous and density) of the constituent materials and the cold spray deposited materials forming the preform 115. The applied current and compressive load can therefore fall within a wide range of values depending on the properties of the material and the preform formed. In the embodiment, the current density of the applied current is 500 to 2000 A / mm ² , preferably 800 to 1500 A / mm ² , and more preferably 1000 to 1100 A / mm ² . The voltage associated with the applied current is preferably 2-3 volts. In the embodiment, the applied compressive load is 10 to 100 kg / m ² , preferably 20 to 60 kg / m ² .

Control of load and heat (here through the application of current) is important to achieve the required structural conversion (recrystallization) from the deposited cold spray lamella structure to the funnel structure. .. The size of the newly formed crystals defines the final mechanical properties while avoiding the melting process. The rate at which the deposited material passes through the rollers is also important because it is related to the rate at which the material is deposited for the continuous production of funnel structures.

An alternative to applying an electric current to generate heat is, for example, the use of conduction heating, which uses a coiled wire around the load device. However, it should be understood that the preferred heating technique is a rapid heating technique that can be applied to the application area by electric current (resistive heating of the material), induction heating, or laser heating.

Example 100A of another embodiment of the process and apparatus of the present invention is illustrated in FIG. 3A. The apparatus 100A separates the process into two separate stages. (A) Step 1 is a preform forming step, and (B) Step 2 is a funnel material forming step. In the first step, as mentioned above, a large number of cold spray particles 112A are deposited on one roller of a pair of rollers 120A to form a solidified particle structure to construct the preform 115A. By doing so, the preform 115A is formed. This uses cold spray non-melting deposits to produce elongated preform strips directly from the powder. Elongated strips can be formed on any sedimentary surface. In FIG. 3A, the preform 115A is deposited on one of the rollers in a pair of rollers 120A rotating in the direction R', which is then compressed to further compact the preform into strips. The preform 115A moves in the supply direction F'through the rollers 120A. However, it should be understood that the preform 115A may simply be cold sprayed onto a hardened metal preform that is not subject to further compression, such as titanium formed on a steel substrate. The preform 115A is then removed and supplied to step 2 at some point after formation. For titanium formed on a steel substrate, this can be achieved using the difference in the coefficient of thermal expansion.

Also, in order to achieve continuous deposition of particles, the cold spray device 110A preferably allows the powder feeder to be switched during the operating period when one feeder has run out of powder, at least two. Includes two powder feeders (not shown).

In the second stage, the formed preform 115A simultaneously compresses, deforms, and heats, so that it passes through the compression device 150. The compression device 150 may include a press device 152, but may include the same rollers as in the first embodiment. The press engages the application area 125 of the preform 115A (see FIG. 3) and applies a compressive load to it while applying "heat" to funnel the lamella structure (in the preform 115A ). Convert to product 130A with structure without melting. The preform 115A moves in the supply direction F'' through the compression device 150. By applying a compressive load and current to the application zone 125 (FIG. 3A), the material in the preform 115A is heated to a local temperature above the recrystallization temperature of the material but below the melting point of the material. Therefore, it is possible to recrystallize the crystal structure of the material of the preform 115A, and the application of a compressive lateral load to form the funnel structure thereby producing the funnel material product 130A is preform 115A. It also helps to compress any voids in the pores inherent in the cold spray lamella structure. The funnel material product 130A can then be formed into the desired product, for example, wires, rods, pieces of steel, and the like. Rollers 160 carry the strip through the compression device 150.

Also, the heat applied can be applied to the application area 125 using some suitable techniques. In embodiments, heat is applied to the application area by at least one of current, induction heating, or laser heating. In the illustrated embodiment, heat is applied using an induction heater 153. However, as in the first embodiment, heat can be applied using alternating current or direct current application to the application area.

The process of the present invention offers several advantages.
1. Accumulation and conversion from powder to funnel structure allows for the rapid production of a wide range of products and product shapes such as rolled products (ie rods, wires, sheets, nuts, bolts, etc.), traditional. Allows cost-effective conversion from industry to current additional manufacturing plants.
2 Mass melting of material is eliminated. The funnel structure is produced directly from the solid powder. This means that in some processes the final funnel structure can be produced directly from the reduced ore powder. For example, a high-strength, high-ductility Ti funnel structure can be produced from crushed Ti sponge as a powder without the costly melting process performed in a controlled atmosphere.
3 Through continuous powder feeding and rapid conversion (in seconds) from a sheet structure to a recrystallized funnel structure, the funnel structure (ie, rods, steel pieces, wires, plates, strips, nuts, bolts, sheets, etc.) (Rolled products such as) can be continuously manufactured. This is important for two reasons. First, in current additional manufacturing processes such as electron beam melting (EBM) and laser-assisted melting (LAM), the melting process results in the formation of cast structures that are generally inferior to funnel structures in terms of mechanical properties. .. Second, the current post-treatment of thin plate structures such as HIP operating at high temperatures in high pressure chambers is a very time consuming batch process, energy intensive and therefore impacts the cost competitiveness of the technique. To exert.
4. The non-melting process of the present invention makes it possible to produce oxygen sensitive materials such as titanium and tantalum in funnel form quickly and at a much lower cost, which were traditionally considered expensive. A new market for the product of tantalum is opened. The same is true for materials that are sensitive to phase transformations and solidification processes.
5 Avoiding the melting process, as a whole, results in a significant reduction in carbon footprint for any funnel material currently produced worldwide through adoption of the present invention.
6 Create new funnel materials available only from the present invention by mixing different powder materials to achieve unique physical and mechanical properties, such as applications in superconductors and semiconductors. ..
7. The present invention can also be used to meet the industry's demand for recycling large particle size powders using cold spraying. Other additional manufacturing industries, such as EBM, require a narrow particle size range in which the residue of the produced powder produces large amounts of excess. This large amount of excess needs to be buried in the ground or melted at a very high cost. The present invention can be used to recycle and convert this excess powder into additionally produced funnel products that can be used on the market.
8 There are applications for the shape and composition of materials such as long elongated pipes, sheets, and wires that are infeasible to process into funnel structures from additional manufacturing processes that use the HIP process.

(Example)
The description of embodiments of the invention in the following examples is in the context of producing a titanium alloy preform of flat strips from titanium alloy particles. However, it is understood that the present invention allows the production of preforms of various metals and alloys thereof and the description should not be construed as limiting embodiments to producing only titanium alloy preforms and funnel products. Will be done.

Example 1 Cold Spray Accumulation of Strips A CGT Kinetic 4000 cold spray system with the following parameters was used to demonstrate the conversion of cold spray lamellae to (recrystallized) funnel structures.
-Cold spray equipment: CGT Kinetics 4000 system-Robot arm for controlling the movement of the cold spray gun: ABB IRB2600
-Number of ultrasonic nozzles: 1
-Standoff: 30mm
-Spray angle: Always perpendicular to the surface-Gas: Nitrogen-Gas stagnation point temperature: 750 ° C
-Gas stagnation point pressure: 25 bar (2.5 MPa)
-Powder supply rate: 21.4 g / min
-Robot movement speed: 5 mm / s

Preform strips were additionally made using folk purity titanium (CP Ti) powder with an average particle size of 26 μm. The Ti powder had an irregular shape. The strip dimensions were 1.5 mm height x 4 mm width x 150 mm length.

It should be noted that the cold spray system in this experiment was not set to achieve a high density structure, but rather to test the effectiveness of the invention for eliminating or reducing porosity. Complete removal of porosity in the as-spray structure requires the use of expensive powders with a narrow particle size range, as well as the use of higher energy (pressure and temperature) from the cold spray system.

CP Ti was deposited on the sides of the stainless steel plate using a commercially available nozzle with the dimensions shown in Table 1. The deposited CP Ti strips were separated from the stainless steel substrate after deposition.

Insitu conversion of strips under high current and load CP Ti strips were simultaneously exposed to high current (3000 amps) and load (25 kg) using a modified spot welder. A control system was added to the spot welder, allowing a large current to pass through the sample for the desired time. This refurbishment was necessary due to the fact that spot welders are designed to locally melt materials and join parts. In the present invention, melting is avoided and an electric current is used to accurately heat the material to the desired temperature for the recrystallization reaction to initiate and proceed. Current (3000 amps) was applied to the spots on the CP Ti strip with different retention times. As shown in FIGS. 4-9, with a total retention time of 2 seconds achieved with a current of 10 pulses with a duration of 0.2 seconds, and a stop of 1 second, the CP Ti structure is complete. Recrystallization and densification have been achieved.

Preparation of funnel recrystallization structure from cold spray thin plate FIG. 4 (a) shows the polished microstructure of cold spray CP titanium exposed to high current and load by arrow 200. The microstructure shows the reaction zone 205. In the reaction zone 205, high density CP Ti is created by exposure to high currents and loads at point 200 on the cold spray CP Ti 210 as it is sprayed. The cold spray CP Ti 201 as sprayed has a porous microstructure.

A significant decrease in porosity was observed in the application zone (or reaction zone 205), confirming the densification of the structure that contributed to improved ductility and improved mechanical properties.

Specimens are etched as shown in FIG. 4 (b), revealing a conversion from a cold spray lamella structure to a recrystallized funnel structure. The presence of needle-like constituents in equiaxed crystal grains in FIG. 4 (b) confirms CP Ti converted from a thin plate structure to a funnel structure during the treatment period.

FIG. 5 represents the application area (or reaction zone) of FIG. 4 (b) at higher magnification, and FIG. 6 shows the porosity of the as-sprayed lamella structure of CP Ti.

The recrystallized Ti-6Al-4V structure with 60 micron previous beta grains in FIG. 7 is achieved from the as-sprayed porous structure in FIG. 7 and 8 therefore show that the current and load applied to the CP Ti strip produces a densified and recrystallized funnel structure similar to the widely used Ti-6Al-4V alloy.

(Example 2)
Three additional experimental runs were performed using the methodology detailed in Example 1 and according to the parameters listed below.
-Run 2: Ti64 grains made from a cold spray structure. Apply 3000 amps for 1 second to a sample with an original height of 4.65 mm. This reduced the height to 2.9 mm, representing a 38% reduction.
-Run 3: Ti64 grains made from a cold spray structure. Apply 3000 amps for 0.8 seconds to a sample with an original height of 4.65 mm. This is reduced to a height of 2.8 mm, representing a 40% reduction.
-Run 4: Ti64 grains made from a cold spray structure. Apply 3000 amps for 5 seconds to a sample with an original height of 4.65 mm. This is reduced to a height of 3.65 mm, representing a 20% reduction.

Etched SEM images of the samples produced for runs 2, 3 and 4 are shown in FIGS. 9-11. The resulting microstructures of runs 2 and 3 show that very small pores are also present, respectively. The resulting microstructure of Run 4 indicates the formation and presence of large crystal grains.

The process described in Example 1 is any metal that can be deposited using cold spray, such as Al, Cu, zinc, Ni, Ti, Ta, steel, as well as metals and ceramics such as carbides and superconductors. It should be understood that it can be applied to metal matrix composites such as mixtures of.

As an example, FIG. 12 shows (A) the microstructure of cold spray formed from a stack of Ni lamellae of cold sprayed and hardened particles (not etched and not yet heat and compressed). SEM micrographs shown, (B) SEM micrographs showing the microstructure of an etched, cold spray formed from a stack of Cu lamellae of cold-sprayed and hardened particles, which have not yet been heat and compressed, (C). ) Provided are SEM micrographs showing the microstructure of an etched, cold spray formed from a stack of Al lamellae of cold sprayed and hardened particles that have not yet been subjected to heat and compression.

The funnel material can be formed from each of the cold-sprayed Ni, Cu, and Al solidified particles, as described in Example 1. With the CP Ti described in Example 1, the preforms of these materials of FIG. 12 are subjected to high current and lateral compressive loads using a technique similar to that described in Example 1. Similar complete recrystallization and densification of cold spray structures will be achieved. The final funnel microstructure resembles the converted Ti structure shown in FIGS. 5 and 7, i.e., the "etc." formed from the cold spray lentil-like lamella structure shown in FIG. It is a "axis recrystallization" structure.

It is understood that the examples and the accompanying description merely indicate a flat strip preform, while controlling the movement of the spray nozzle and / or the material deposit surface can generate various configurations of the preform. sea bream. Similarly, it should be appreciated that voids or cavities can also be introduced into the preform by introducing non-deposited areas or zones in the spray pattern of the cold sprayer where no material is deposited.

Similarly, the examples and accompanying descriptions simply indicate a preform with a nearly constant cross-sectional area, while conical shapes, conical portions, or stairs or tapered shapes (large to small diameters), etc. It should be understood that it is also possible to form preforms with variable or non-constant diameters such as.

Similarly, the examples and accompanying statements simply use other types of heat sources, especially rapid heating sources, to heat selected areas of the sample with respect to exemplifying the use of electric current to heat the sample. However, it should be understood that loads can be applied at the same time. Examples include induction heating or laser heating.

Although not detailed, it should be understood that the above materials can receive:
-Microstructure analysis using metallography and light microscopy to compare the transformed and recrystallized structure with the as-sprayed structure, especially with respect to the distribution of pores.
-Measurement of mechanical properties by microhardness to compare as-sprayed and recrystallized materials.

Those skilled in the art will appreciate that the invention described herein can be modified and modified beyond those specifically described. It is understood that the invention includes all such modifications and modifications that fall within the spirit and scope of the invention.

When the terms "prepared, included", "prepared, included", "prepared, contained" are used herein (including claims), they are the features, integers mentioned. , Steps, or components are specified, but should be construed as not excluding the existence of one or more other features, integers, steps, components, or groups thereof.

30 Thin plate-shaped particles 35 Equiaxial grain structure 40 Equiaxial grain structure 45 Void 50 Thin plate 100 Device 100A Device 100a Cold spray device 110 Cold spray device 110A Cold spray device 112 Cold spray particles 112A Cold spray particles 115 Preform , Structure 115A Preform 120 Roller 120A Roller 125 Application Area 130 Rohto Recrystallization Structure 130A Product, Roh Material Product 131 Current Source 132 Pneumatic Load Device 150 Compressor, Compressor 152 Presser 153 Induction Heater 160 Roller 200 Arrow , Point 205 Reaction Zone 210 Cold Spray CP Ti

Claims (39)

A process of producing a product with a recrystallization and densification structure from a cold spray deposition preform with a solidified particle structure .
It comprises the step of simultaneously applying heat and compressive load to the application area of the cold spray deposition preform using a compressive load applyer.
The compression load applyer is applied laterally to the application area and
The compressive load and heat applied to the application zone raises the temperature of the preform material in the application zone between the recrystallization temperature and the melting point of the material , thereby the cold. A process of converting the solidified particle structure of a spray deposition preform into a recrystallization and densification structure . The process of claim 1, wherein the heat is applied by a rapid heating technique selected from current, induction heating, or laser heating . The process of claim 1 or 2, wherein the heat is applied using a current comprising at least one of alternating current or pulsed direct current. The process of claim 2 or 3, wherein the heat is applied using a current having a current density of 500-2000 A / mm ² . The process of claim 3 or 4, wherein the voltage associated with the applied current is 2-3 volts. The process according to any one of claims 1 to 5, wherein the applied compressive load is 10 to 100 kg / m ² . The process according to any one of claims 1 to 6, wherein the process comprises a continuous manufacturing process. The process according to any one of claims 1 to 7, wherein the preform is an elongated body. The process of any one of claims 1-8, wherein the preform comprises strips, sheets, wires, bars, or bars. The process of any one of claims 1-9, wherein the compressive load is applied using at least one roller configured to compressally engage the preform. 10. The process of claim 10, further comprising at least two rollers in which the preform is supplied and compressed. 10. The process of claim 10 or 11, wherein at least one roller is configured to apply heat to the preform. The process of any one of claims 10-12, wherein at least a portion of the rollers comprises a conductive material. The process of any one of claims 10-13, wherein at least one roller comprises a cooling system or cooling device. Before applying heat and compressive loads
One of claims 1-14, further comprising the step of forming a preform having a solidified particle structure using cold spray deposition to additionally construct the structure in a desired configuration. Described process. The compressive load is applied using at least one roller configured to compressally engage the preform, and one of the at least one roller before the preform is compressed. 15. The process of claim 15, which is formed on the surface of a roller. 15. The process of claim 15 or 16, wherein the preform is formed on or around a feed axis to which the preform moves during the process. The process according to any one of claims 15 to 17, wherein the preform is formed by depositing a material on a deposit surface. The step to form is
Steps to use a cold spray giver to deposit cold spray material on or around the supply axis to form a product deposit surface, and
With the step of continuously depositing the material on each upper product deposit surface, using cold spray deposition to form a subsequent sedimentary layer of the material.
A step of moving at least one of the cold sprayer or the preform axially relative to each other along the supply axis.
The process of any one of claims 15-18, comprising the step of forming a preform of the selected length thereby. The process of any one of claims 15-19, wherein the preform is formed as a continuous element . The process of any one of claims 15-20, wherein the preform is formed as a strip, sheet, wire, rod, or bar. 22. The invention of any one of claims 15-21, wherein the heat and compressive loads are applied to the application area of the preform immediately after the formation of the application area of the preform by cold spray deposition. process. 13 . Described process. The process according to any one of claims 1 to 23, wherein the cold spray deposition preform comprises a mixture of at least two different powders. A recrystallized and densified structural preform formed from the process according to any one of claims 1 to 24. A device for producing products with recrystallization and densification structures from cold spray deposition preforms with a solidified particle structure .
A compression load applyer configured to simultaneously apply heat and compression load to the application area of the cold spray deposition preform is provided .
The compression load applyer applies the compression load applied laterally to the application area, and applies the compression load.
An apparatus in which the applied compressive load and heat raise the temperature of the preform material in the application area between the recrystallization temperature and the melting point of the material. 26. The apparatus of claim 26, wherein the heat is applied by a rapid heating technique selected from current, induction heating, or laser heating . 26 or 27. The apparatus of claim 26 or 27, wherein the heat is applied using a current comprising at least one of alternating current or pulsed direct current. The compression load applyer
28. The apparatus of claim 28, wherein the applied current is configured to provide a current having a current density of 500-2000 A / mm ² . The device according to any one of claims 26 to 29, wherein the compression load applyer can apply a load of 10 to 100 kg / m ² to the application area. The device according to any one of claims 26 to 30, wherein the compression load applyer comprises at least one roller configured to compressally engage the preform. 31. The apparatus of claim 31, further comprising at least two rollers in which the preform is supplied and compressed. 31. The device of claim 31 or 32, wherein at least one roller is configured to apply heat to the preform. The device of any one of claims 31, 32, or 33, wherein at least a portion of the rollers comprises a conductive material. The device according to any one of claims 31 to 34, wherein at least one roller includes a cooling system or a cooling device. The device according to any one of claims 26 to 35, further comprising a cold spray depositing device for forming the cold spray depositing preform on the deposit surface. 36. The apparatus of claim 36, wherein the preform is formed on at least one surface of the rollers before being compressed by the rollers. 36 or 37. The apparatus of claim 36 or 37, wherein the preform is formed on or around a feed axis to which the preform moves during the process. The process according to any one of claims 1 to 24, which is carried out using the apparatus according to any one of claims 26 to 38.