JP2002518587A - Material surface modification simplification method - Google Patents

Abstract

(57) [Summary] The ability to modify the surface area of a material is greatly improved by irradiating the surface of the material with a pulsed ion beam having a predetermined pulse repetition rate, a predetermined pulse width, and a predetermined applied energy. Let it.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD The present invention relates to a method for modifying a surface area of a material. The present invention is applicable to a wide variety of materials and includes magnetically sealed anode plasma (MAP) ions having a predetermined pulse repetition rate, a predetermined pulse width, and a predetermined applied energy for modifying the surface area. Utilizes an ion beam extracted from the source.

BACKGROUND OF THE INVENTION As the demand for improving the performance of materials escalates, the demand for improving the properties of materials through surface modification is increasing. One method of surface modification involves rapidly heating and cooling the surface of the material to change the composition of the surface and the spatial arrangement of the material on the surface. Such methods also severely alter the mechanical, chemical, electrical, optical, and other properties of the surface. However, there is no commercially viable technology to process large quantities of moldings or large areas consistently, especially when the processing temperature exceeds the melting point of the material, making rapid heat treatment widely available for commercial use. It was a long-standing obstacle that could not be achieved.

[0003] One attempt to thermally change the material involves using a laser.
However, the use of lasers has some disadvantages. The efficiency of coupling laser energy to a surface is highly dependent on the optical properties of the surface being treated. Therefore, use of a laser causes uneven processing due to surface defects and unevenness. Also,
Due to the use of small beam spots (typically much smaller than a few square centimeters) that need to wipe the surface to process large areas, the laser is limited and undesirable mechanical and Induces electrical edge effects. This edge effect occurs because the material previously treated with the laser beam is reprocessed because the laser beam passes through adjacent areas. The surface can also be modified by thermal cycling using a pulsed electron beam. Pulsed electron beams have problems with beam transport and depth of penetration into the material.

Another method of thermally changing the surface properties of a material is to use a pulsed ion beam. However, this entails problems with using the conventional pulsed ion beam method. Similar to a laser, the cost per unit processing area is high when using a conventional ion beam. In addition, ion beam generators using "flashover" (i.e., a surface arc plasma source) produce debris that contaminates the surface being treated. Further, "flashover" has a negative effect on uniformity, resulting in poor reproducibility and beam efficiency.

[0005] There is a need for a low-cost, simple method in a technology that allows the surface properties of a material to be modified by thermally changing the surface properties of the material with an ion beam.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a material surface modification in which the depth of the surface to be processed or near the surface to be processed can be controlled and the material to be melted or considerably heated is limited to a depth of a few microns or less It is to provide a method.

Another object of the present invention is to provide a material surface modification method capable of rapidly cooling a material, and particularly when the depth of a processing object is small, a large area is efficiently used and a relatively low surface area is provided. Energy and high processing rate.

According to the present invention, the above and other objects can be achieved, in part, by a method for modifying a material surface, which method uses a magnetically confined anodic plasma (MAP) with little rotation relative to the surface of the material.
Irradiating a pulsed ion beam extracted from the ion source and having a predetermined pulse repetition rate of at least 0.1 pulses / second and a predetermined pulse width in the range of about 20 nanoseconds to 0.05 milliseconds; , characterized in that it comprises the step of applying energy with a predetermined energy density in the range of about 0.01 J / cm ² to about 20 J / cm ² with respect to the surface.

[0009] Further objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. However, the embodiment of the present invention merely describes the best embodiment for carrying out the invention with an example. As will be seen, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious aspects, all without departing from the invention. Accordingly, the drawings and description are illustrative of the nature and are not to be regarded as limiting.

DETAILED DESCRIPTION OF THE ION BEAM SOURCE OF THE INVENTION According to embodiments of the present invention, the surface of the material may have a predetermined pulse repetition rate of at least 0.1 pulses / second, and a pulse rate of between about 20 nanoseconds to about 0.05 nanoseconds. a predetermined surface by ion magnetic confinement anode p (MAP) ion beam extracted from the source by irradiating with a pulse width in the range of about 0.01 J / cm ² to about 20 J / cm ² in the range of milliseconds By applying the predetermined energy to the surface, the surface of the material can be modified.

The ion beam source utilized to perform the method of the present invention is an ion beam source that provides a magnetic confinement or a magnetically induced anode p source, such as a (MAP) ion beam device. The MAP ion beam device is disclosed in US Pat. No. 5,473,1.
65, 5,525,805, 5,532,495, 5,656,819, and 5
, 900, 443, the entire disclosure of which is incorporated herein by reference. According to embodiments of the present invention, the ion beam is a repetitive, extractable ion beam having a repetition rate of at least about 0.5 pulses / second. Such pulses can be provided without significant damage or debris of the beam device.

According to embodiments of the present invention, the ion beam is extracted from the ion source with little rotation. As used herein, "substantially no rotation" means that the annular ion beam extracted from the beam device has an axial velocity of less than 30% toward the target after passing through the entire magnetic field of the beam device, that is, the axial velocity. The ratio of the rotation speed to
Means that it is pulled out of the beam device with an azimuthal rotational speed of less than.
According to an embodiment of the present invention, the ion beam has, for example, a proton or nitrogen ionic species structure and is at least 60% species pure and the beam is 0.01 Joules /
cm ² or more, for example, with an applied energy density level of about 0.1 J / cm ² to about 20 J / cm ^2. In the present invention, the p position is determined not by the material surface but by the distribution of the magnetic field. In other words, the position of the source ions accelerated by the accelerating electric field between the anode and the cathode of the beam device is determined directly by the shape and magnitude of the induced magnetic field of the beam device, not directly on the solid surface.

In one embodiment of the invention, the contamination is at least partially cleaned by irradiating an area of the surface with an ion beam having the required parameters. As used herein, "contamination" refers to the presence of unwanted material in surface areas. As used herein, "cleaning" includes preferentially removing contaminants from a surface, or altering the composition and chemical state of a surface by altering the distribution of contaminants on a material surface.

By altering the atomic arrangement of the surface, the composition of the surface, and the topography of the surface, the properties of the coating and similar layers subsequently applied to the surface can be altered. For example, by combining the sealing and smoothing of cracks and pores with the evaporation of impurities, it can be expected to improve the adhesion and inherent properties of a layer applied to the surface by a technique such as sputtering or vapor deposition. As used herein, "surface" means both a nominal two-dimensional surface and a plane of a material, including, for example, near the surface to a depth of about 300 micrometers. Examples of contaminants that can be cleaned from surfaces according to the present invention include, for example, iron surfaces contaminated with hydrocarbons, metal surfaces contaminated with oxides, cemented carbide surfaces contaminated with tin or titanium nitride, and metals. There is a contaminated ceramic surface. In one embodiment, the contaminated surface is cleaned by elevating the surface temperature to a temperature above the vaporization point of the contaminant and below the vaporization point of the surface material to evaporate the contaminant.

Therefore, by raising the surface temperature above the vaporization point of the contaminant, and removing unnecessary low vaporization point contaminants on the surface, the contaminated surface without evaporating other surface components Can be cleaned. This cleaning method can be performed without using a conventional cleaning solvent. Referring to FIG. 2C, in particular, contaminants having a vaporization point lower than that of the surface material have been removed in this manner. For example, iron has a melting point of 1576 ° C, with hydrocarbon contaminants typically having a vaporization point below 1000 ° C. Therefore,
The iron surface contaminated with hydrocarbons is cleaned by irradiating the surface with an ion beam and raising the surface temperature to a temperature higher than the vaporization point of hydrocarbons but lower than the melting point or vaporization point of the iron surface. it can. That is, hydrocarbon contaminants can be removed without melting the iron surface and solidifying it again. Even if the contaminants are evaporated and the iron surface is melted, it can be cleaned. Evaporation of the contaminants can facilitate mixing of the contaminants with the surface material.

In another embodiment, the surface is raised by at least partially mixing the contaminant and the surface material by raising the temperature of the surface material to a temperature sufficient to melt the contaminant and the surface material. Wash. At least partial mixing of two or more components of a surface material by melting, by liquid phase mixing, convection mixing, diffusion mixing, or other mixing methods, results in a new surface and one of the mixed materials Alleviates the harmful effects of For example, by raising iron (melting point is 1576 ° C.) and chromium (vaporizing point is 2665 ° C.) to 2000 ° C., both can be melted and mixed. In this case, as long as the surface temperature is lower than the vaporization point of iron and chromium,
By liquid phase mixing or convective mixing, both components of iron and chromium are melted and mixed without evaporating either component.

In another embodiment, the surface is at least partially cleaned by irradiating the surface with an ion beam to raise the surface temperature to at least the melting point of at least one of the surface materials rather than the contaminants. I have. Melting the material around the contaminant mixes the material with the contaminant by convective, diffusive, and / or other diffusion mechanisms. For example, if particles having a high melting point (temperature A) are at least partially on the surface of a material containing a material having a low melting point (temperature B), the ion beam is used to raise the surface temperature to a temperature higher than the temperature B and lower than the temperature A. When raised, the particles at least partially mix with the low melting point material. Contaminants, such as dust, inclusions, and second phase particles, are melted and entrapped in solid solution by rapid cooling after beam heating is complete.

In another embodiment, the surface is irradiated with an ion beam to raise the temperature to a temperature sufficient to melt the contaminants and surface materials and above the vaporization point of one of the surface materials and the contaminants. Cleaning the contaminated surface by removing contaminants and / or potentially promoting at least partial mixing of the surface material with the contaminants.

The removal of contaminants plays a significant role in changing some properties of the surface. For example, removing oxides from the surface improves the conductivity and light reflectivity of the material surface. Metal oxides tend to exhibit low electrical conductivity and the surface tends to be dull. The parameters of the pulsed ion beam treatment can be selected to evaporate and remove the oxide. As a result, the surface is almost free of oxides and generally brighter,
Normally the conductivity increases.

[0020] In yet another embodiment of the present invention, a zone on a contaminated surface is purified by inducing contaminants to move toward the outer boundary of the surface. Subsequently, the contaminants that have migrated are removed from the surface.

In zone purification, contaminants with different properties, such as melting points, other than the rest of the surface material, are formed when the surface material resolidifies at the deepest melt depth in the irradiated material. It is then swept away along the re-solidification surface that progresses toward the surface. As a result, contaminants accumulate on the surface. At the surface, this contaminant can be removed by evaporation or other treatment. However, even if the contaminants are not removed from the surface, the underlying material is purified from the contaminants.

In a further embodiment of the invention, the layered surface is irradiated with an ion beam to separate and / or remove layers such as coatings from the surface. In one embodiment, the layers to be separated and / or removed are multiple layers.

The separation and / or removal of layers is achieved, for example, by delamination due to the expansion and contraction of the surface volume, resulting in cracks, mechanical separation and other phenomena associated with stress waves caused by thermal cycling. Causes stress. Thermal cycling can be performed by heating and / or melting the surface below the layer to be removed. Alternatively, separation and / or removal of a layer can be accomplished by evaporating a surface material beneath a given layer to create pressure between the layer and the underlying surface material, forcing the layer to separate from the underlying surface. Is also good. For example, when energy is applied to the multilayer coating with an incident ion beam, the zinc layer below the titanium outer layer reaches the vaporization point, but the titanium outer layer remains in a solid or liquid phase. The pressure due to the evaporation of the underlying zinc vapor layer separates and / or removes the titanium outer layer from the zinc surface, thereby effectively removing the titanium layer.
In FIG. 4, about 1 micron of the zinc layer has evaporated, with a 1 micron thick layer of titanium remaining below its vaporization temperature. If evaporation occurs first below the surface,
Not only is the upper layer removed, but a new surface that is melted and homogenized is ready for subsequent use. FIG. 5 shows the evaporation of the partial surface layer before the outer surface layer reaches the vaporization temperature.

According to another embodiment of the present invention, the surface is heated by irradiating the surface with an ion beam having a predetermined pulse repetition rate, a predetermined pulse width, and a predetermined applied energy to substantially change the granular surface. The crystalline surface is modified by cooling the surface at a sufficient rate. As used herein, "crystalline surface" generally refers to a surface that includes at least some regions where atoms or molecules are in a regular spatial pattern, crystalline arrangement, or similar surface property state. As used herein, "altering a crystalline surface" generally refers to altering the regular spatial pattern of atoms or molecules, the crystalline arrangement or similar surface properties, and / or the regular spatial arrangement of atoms or molecules. This means changing the size of the region located above.

According to an embodiment of the present invention, the cooling after melting is faster than 1 million ° C./sec.
Rapid melting and re-solidification dramatically reduces particle size. The molten surface becomes nanocrystalline (particle size much smaller than 1 micron) or amorphous (no particles). This can be achieved by using a short ion beam pulse, such as a 150 ns pulse during the period. As shown in FIG. 2C, in steel, 10 ⁸ -10 ⁹ K
/ S cooling rate. Purifying the particles improves the surface for the next coating. For example, the refinement of the particles results in a stronger, sometimes harder surface, which improves the performance of the coating under mechanical stress.

In another embodiment of the invention, a surface having cracks, pores or other low-density features is modified by irradiating the surface with a pulsed ion beam of the required parameters to reduce cracks, fines on the surface. Holes or other low density features may be reduced or eliminated. As used herein, "low-density shape" refers to a shape made of less material than the immediate area.

[0027] Before the surface is melted and the surface is re-solidified, the liquid flows into and fills the low-density features such as cracks and pores, thereby reducing or removing the low-density features. It is possible. Reducing or eliminating low-density features is a significant advantage in creating a film-forming surface. For example, cracks in the coating surface can result in defects in the uniformity of the coating, and can also be locations where mechanical stresses can be induced which can lead to cracking of the coating. In addition, contaminants may collect at the cracks. Subsequent coatings on the contaminant contaminated sites may have poor adhesion to the surface due to the presence of the contaminants.

By densifying the surface and removing pores connected to the surface, the effectiveness of other material modification treatments can be increased. For example, if there are pores connected on the surface, the effectiveness of hot isostatic pressing or other press densification may be reduced. The pores that connect at the surface create a passage that balances pressure between the interior and exterior of the molded article, reducing the ability of the pressurized medium to densify the molded article. By sealing the surface of the pores, it is possible to generate a pressure difference, and therefore, it is also possible to realize densification of the molded product. Another advantage of pore sealing is that the corrosion resistance of the surface is improved by preventing the corrosive agent from being trapped or penetrating from the outside to the inside of the molded article.

The fatigue life of the material can be extended by densifying the surface and removing cracks. Cracks are well known as places where they can spread and grow in a fatigue environment. The spread of such defects can eventually lead to cracks and breakage of the molded article due to plastic deformation. Eliminating or reducing the number and size of such shapes by ion beam processing can increase the fatigue life of the material.

The densification of a surface having many low-density shapes such as cracks and pores is achieved by irradiation with a pulsed ion beam, pretreatment “shot peening”, and melting and flowing of a processing material into a liquid phase. Can be improved by combining it with a similar technique that makes the size of cracks and pores more complete and easier to seal.

In still another embodiment of the present invention, the surface is irradiated with an ion beam having a predetermined pulse repetition rate, a predetermined pulse width, and a predetermined applied energy to change the topography and spatial gradient of the surface. As used herein, the term "terrain" refers to a surface configuration that includes the relief of a surface and the location of its shape. The term "spatial gradient" refers to the rate of change of the relative position of adjacent shapes or materials on a surface.

By a thermal cycle such as melting or evaporating the surface, it is possible to change the topographical features of the surface in various ways, such as roughening, smoothing and patterning. In an embodiment of the present invention,
Increasing the surface temperature above the melting point of at least one material on the surface, increasing the surface temperature to a point below the vaporization point of the surface, increasing the surface temperature with little removal of the surface material, surface temperature To a point above the vaporization point of at least one material on the surface. For example, the surface of the catalyst can be increased in surface area by reforming to refine the grain structure. Changes in surface topography and microstructure can be achieved by rapidly melting and resolidifying, evaporating, evaporating and recondensing the pre-existing surface catalyst material, and the like. Such a change can improve the activity of the catalyst.

By flattening at least a part of the surface, it is possible to smooth the surface and reduce the spatial gradient, and reduce or substantially eliminate the protrusions protruding from the nominal surface. Protrusions such as burrs can be reduced or almost eliminated. By employing multiple cycles of melting and resolidification, burrs and surface structures that are much larger than the melting depth can be reduced or eliminated. Also, the projections can be reduced or removed by evaporation. Protrusions that protrude from the nominal surface of the material make the subsequently applied coating non-uniform, and this relatively weak mechanically coated protruding structure contacts another surface, for example, in a wear environment. Cracks occur in the coating when peeled off. The above method allows for planarization without removing surface material and can preserve the overall dimensions of the treated surface.

The present invention is also applicable where the surface is smoothed to reduce or substantially eliminate recesses below the nominal surface. As used herein, the term "recess" refers to the area penetrated from the nominal average position of the surface. By eliminating or partially smoothing out depressions, especially depressions with high spatial gradients,
The adhesion of the film to be subsequently applied is enhanced. This is because surface depressions can lead to stress concentration, defects or non-uniformity of the coating, and early destruction due to cracking or peeling of the coating. Such reduction of stress concentration, reduction of surface gradient, and improvement of surface quality can extend the life of the uncoated surface. FIG. 6 shows a surface that has been treated according to the method of the present invention and has reduced surface differences and high spatial gradients.

Furthermore, smoothing of the terrain can have a significant effect on the frictional and optical properties of the surface. The smoother the surface, the lower the frictional force when sliding against the adjacent surface. Also, a smooth surface will increase the reflected light and increase the specular reflection of the light.

The present invention is also applicable to surface roughening. As used herein, the term "roughen" refers to forming or increasing the size of the protrusions above the nominal surface. An example of such a protrusion is a sharp spire. One of the advantages of this method is that the surface can be roughened without removing material, as shown in FIGS. 3B, 3C and 6. Roughening results from a combination of effects such as volume change due to thermal cycling, three-dimensional effects, uneven heat flow, and surface tension during resolidification. FIG. 3b shows an example of a wavy structure or phase formed on a copper surface.

The degree of terrain change can be adjusted by adjusting the melt depth during processing. By reducing the melt depth, a smoother surface can be created.
The melt depth can be adjusted by adjusting the energy applied to the surface. As shown in FIGS. 2C and 2D, the lower the applied energy, the smaller the melting depth. The effect of volume expansion can be minimized by preheating the material to be processed. As a result, it is possible to suppress a change in local temperature during cooling between the surface layer and the unprocessed material that is not significantly affected by the thermal cycle caused by the ion beam below the surface layer.

In one embodiment, the surface is roughened by increasing the temperature of the surface to a point above the vaporization point of at least one material on the surface. Rapid evaporation of a surface can generate stress waves in the material due to the reaction forces created by the heated material leaving the surface at a rate characterized by temperature and other energy states. At times, the material surface may already be in the liquid phase. If the stress wave collides with the surface while the surface is still molten, the material can be scattered and released from the surface. The topography created by the scattering of material can be cooled by rapid resolidification.
Rapidly evaporating the material on the surface during a number of pulses, causing the evaporated material on the surface to re-condense and rapidly re-solidify as reached by quenching from the gas or liquid phase. Alternatively, the surface of the amorphous material can be formed with a very rough surface.

Depending on the initial structure of the surface, it is possible to produce a sharp spire by reapplying energy. Depending on the material, the incident beam energy and the number of pulses, the spire structure can be grown to protrude significantly above the original surface. FIG. 7 shows such a surface (formed using hundreds of pulses at an energy level of 4 to 8 joules per square centimeter). Or,
FIG. 3c shows a surface including bumps and spikes formed using 40 pulses at 2-4 joules per square centimeter. These rough structures provide a number of advantages, such as being able to be used as an electric field increase point that emits electrons when an electric field is applied. FIG. 3c shows an example of surface roughening where evaporation is important. As shown in FIG. 7, a sharp spire can be formed on the surface by repeatedly ablating the surface.

Surface roughening increases the exposed surface area, increases the number of mechanically bonded sites for subsequently applied layers, various surface topography that allows more or less friction And brings several advantages. Thereby, the lubricity can be controlled, and a point having a topography that increases the surrounding electric field can be formed, and the field emission from that point can be facilitated. This ability to create surfaces is important for both bare and coated surfaces. If the surface is prepared for the next coating process, the rougher the surface, the more surface area the coating can bond to and the greater the mechanical bonding of the coating to the surface. Roughened or textured surfaces, whether uncoated or coated, can provide lubrication gathering points and provide higher anti-friction performance for extended periods of use. .

In addition, it is also possible to change the electronic and chemical properties of the surface by texturing the surface. When the present invention is used for surface smoothing, the ability of the surface to withstand the presence of a strong electric field without emitting electrons can be increased by reducing the number of individuals that increase the electric field. Also, by reducing the surface roughness, the amount of material exposed to the corrosive can be reduced. On the other hand, by roughening the surface, the tendency of the surface to emit electrons in the presence of an electric field can be enhanced, and the surface area can be increased to increase the chemical reactivity of the surface.

Further, according to the surface patterning, the surface is smoothed and the surface is roughened.
Even so, the optical characteristics of the surface can be changed. That is, the rougher the surface
, Can make the surface less reflective, less mirror-like, more diffuse,
The smoother the surface, the more reflective, more specular and less diffuse the surface
can do. In particular, the level exceeding the melting temperature (usually 2 to 10 J / cm ^Two In the energy range of), the surface can be made shiny and reflective.

In another embodiment of the invention, the surface is raised to a temperature below its melting point by irradiating the surface with an ion beam having the required parameters. Its surface is
It may consist of one or more individual constituent materials, which may be present as layers, sub-layers, separate mixed zones or islands.

When any material, such as a mixed material, is processed by thermal cycling at a temperature lower than the melting point of any of the components, dislocations leading to an increase in hardness and compressive stress, as well as mixing of the material, especially those having various coefficients of thermal expansion, Other effects due to thermal expansion and contraction of the material can be generated. By heating at a temperature lower than the melting point, mechanical and
Solid phase rearrangement of atoms can occur using a crystal phase change process or other solid phase process that can change electrical, chemical and other properties.

In yet another embodiment of the present invention, the surface comprising at least two components is modified by increasing the temperature to above the melting point of at least one component. The processing of the mixed material by thermal cycling at a temperature above the melting point of at least one component material reduces the particle size of the molten material, increases microstructure defects in the molten material,
A variety of beneficial effects can be provided, such as partial melting of the higher melting material into the molten material, altering the properties of the molten material (by solution, re-deposition or similar effects). Redepositing a portion of the higher melting material that has been partially dissolved is one embodiment of this effect.

As shown in FIG. 8, according to the present invention, a tungsten cemented carbide material with 6% cobalt binder was treated at ² J / cm ² . This treatment melted the cobalt binder without melting the tungsten carbide particles. In a cutting test, this treatment was able to extend the life of a tungsten carbide tool used for cutting a cast aluminum alloy by 60%. This is because tungsten carbide particles can be refined by refining cobalt, partially dissolving tungsten carbide in a binder, and reprecipitating the solutionized components during cooling of the material and subsequent post-heating. It may be said that this is due to a combination of effects caused by melting the cobalt binder without melting.

In yet another embodiment of the present invention, a surface is constructed from a first component having a first melting point, and a second component having a second melting point is added to the surface (the second component). 1
Is lower than the second melting point), the surface is modified by raising the surface temperature to a temperature higher than or equal to the first melting point and lower than the second melting point.

The method can be used to incorporate another material into the surface, such as a material with a higher melting point than the original surface. For example, by melting the surface, a fine particle having a size several times as large as the range of ions in the beam is melted by heating all or a part of the particle or only by heating, so that the fine particle is at least partially bonded to the surface, Fine particles can be mixed into the surface. The method can be used to mix ceramic with metal or metal with ceramic to change the electronic properties of the surface. As an example,
By mixing a metal with the surface of an insulator or a semiconductor, the discharge breakdown voltage of electrons can be reduced and the average electron emission rate of the surface can be increased. By extending this effect to a large number of pulses, the material composed of the fine particles can be completely or partially mixed with the surface to form an alloy surface. This effect can be used to deposit new material to the desired depth on the surface by repeatedly adding new particulate material. Utilizing this technique, the weld coating can also be incorporated into the surface material.

Processing of mixed materials with different melting points can be used to create new materials. For example, an ion beam melts mixed powders, each having a different melting point, to form a fused joint material, or melts at least one of the components of the powder mixture to form a partial alloy material or a complete alloy material. Available for use. One embodiment of this technique is the melting of a mixed powder material. By repeatedly adding new powder and melting at least one component of the mixed powder to form a bonding material, a new alloy layer of a desired depth can be formed. These layers can also be bonded to these materials by melting the interface with the lower or upper material.

In yet another embodiment of the present invention, the interface between the layer and the surface is irradiated with an ion beam having the required parameters to at least partially mix the stack surfaces. The difference in melting points between adjacent layers can be used to mix or bond the two layers by melting the lower layer at the lower melting point, with or without melting the upper layer. The interface between the layer and the surface can be completely or partially mixed. Even if complete mixing and homogenization of the interface cannot be achieved, partial mixing
It results in a graded interface with no apparent boundaries with a high spatial gradient. Otherwise,
There will be sites that are favorable for mechanical defects such as cracks, dissimilar metal corrosion, and other harmful effects.

In yet another embodiment of the present invention, the surface is modified by redepositing the surface with the precipitate. That is, the surface is irradiated with a pulsed ion beam having a constant acceleration voltage, a rotational speed to axial speed ratio, a pulse width, an ion species composition, and an applied energy level.

As an example, 17-4PH stainless steel was hardened by the method described above. That is, the untreated stainless steel had a Knoop (100 g load) hardness measurement of 414. After the treatment, the hardness dropped to 282. This is probably due to the dissolution of the existing precipitates that were present to increase the hardness of the precipitation hardened material by the above treatment. After 2 hours of post-treatment heating or tempering at 500 ° C., the hardness is 5
It has risen to 30. This increase in hardness is presumably due to the re-precipitation of finer granular precipitates than originally present, which increased the hardness. The present invention is also applicable to generating a dislocation by subjecting a region near the surface of a material to a thermal cycle. Such thermal cycling generates stress waves and generates dislocations in the material, especially the metal.
Such dislocations increase hardness and result in residual compressive stresses that are beneficial in many applications. By using the above method to achieve this, the surface treatment can reduce fatigue problems and wear and extend life.

According to the method of the present invention, it is possible to separate the mixed material without affecting the underlying material by removing at least one constituent material of the mixed material. This is achieved by selective evaporation and / or selective dissociation. Many materials, such as cermets, composites, intermetallics, alloys, and the like, consist of mixtures containing different components that each react differently to thermal cycling. These materials can be separated by selective evaporation or dissociation based on differences in vaporization points and melting points between different components.

FIG. 9 (Al / Al ₂ O ₃ treatment) illustrates a mixed material separation method according to the present invention. FIG. 9 shows a state in which aluminum has been separated from an aluminum mixture or an alumina mixture while leaving a rough surface under the influence of aluminum evaporation.
By selecting the type, energy and intensity of the incident ion beam, the temperature of the processing material can be selected to evaporate components at lower vaporization points without evaporating material at higher vaporization points. This effect can be used to displace the surface without affecting the underlying material. This is advantageous when the dislocation material is a film, and it is desirable that the underlayer hardly changes by the above-described processing.

[0055] Yet another embodiment of the present invention provides that the surface comprising the first and second components is raised to a temperature sufficient to at least partially remove the first component. And a technique for modifying the surface.

The topography can be changed by removing components on the low melting point side. FIG.
10a and 10b show the treatment on two stainless steel surfaces with different sulfur (440 ° C. low vaporization point material) content. The sulfur may be present in the alloy as free sulfur or may combine with another element to form a sulfide. 10a and 10b, the surfaces are of 303 stainless steel and 304 stainless steel, respectively. Both surfaces were treated at approximately 2.5 joules per square centimeter. FIG. 11 shows a heat cycle by this processing. The rough surface formed on the 303 material
The low sulfur point material in the 303 material was shown to have evaporated due to the high sulfur content.
The sulfur content of the 304 material is much lower because the treated surface was much smoother.

By forming a rough or textured surface by evaporation or dissociation, different chemical properties including different appearances, different coefficients of friction and lubricity, different wear and fatigue properties and chemical activity rates Surface can be created. This effect
It can be used to form surfaces and films with various porosity. Further, a rough surface structure that can be used as an electric field increasing point that emits electrons when an electric field is applied can be formed. This can also be achieved using other surface roughening techniques described in the text. A material that reacts to a thermal cycle by dissociating into constituent elements (eg, TiN) can also provide a similar effect due to the dissociation. The method of the present invention can be used to remove dissociable material from a surface or from a substrate consisting of other materials that do not dissociate or evaporate unless a high temperature is reached. Removal of the dissociable components can be used to achieve the same effect as described above when using evaporation.

Mixing or alloying, in which the evaporating or dissociating material is re-welded and mixed with the remaining material, can affect the surface properties of the formed surface.

A surface can also be repaired using the present invention by adding material to a portion of the surface and using a beam to melt bond the new material to the surface. This technique can also be used to repair damaged or imperfect surfaces. By melting the new material and the original lower layer material, the new material will undergo liquid phase diffusion, or
It will be coupled by convective mixing. This creates a graded interface that resists delamination. Furthermore, melting only one of the materials will improve the diffusion bonding of the new material and improve the adhesion. Use of a third material that melts more easily than another material to be bonded can enhance the bonding of the multilayer composite material.

[0060] Embodiments of the present invention are well suited for modifying surfaces formed from powdered materials. Use in powder metallurgy includes homogenization, cleaning, and heating and / or melting, liquid phase bonding and mixing, which the present invention can achieve as shown in the improvement of the metal injection molding of FIG.
It will benefit from surface texturing, smoothing, densification and hardening by the formation of fine-grained material. Techniques for processing mixed materials are also well suited for use with powdered materials and metals and non-metals.

The method of the present invention can also be used to implant ions into a polymer surface.
This provides advantages such as increased hardness, reduced magnetic permeability, and increased electrical conductivity. The use of this method also offers some unique advantages for treating polymer surfaces. (1) Treatment with short (<1 ms) pulses reduces the time the surface is at a temperature high enough to damage the polymer. Therefore, faster processing can be realized using stronger ionic strength.

(2) The process utilizing short pulses reduces the maximum allowable surface temperature during processing by reducing damage from exceeding the standard maximum allowable processing temperature for continuous, long-term processing. To raise. Yet another advantage of this high tolerable processing temperature is that the effectiveness of crosslinking is increased by higher temperatures and consequently by increasing the mobility of the molecules during and immediately after processing. Therefore, it is possible to reduce the amount of ion addition necessary to realize a specific hardness and other parameters caused by the processing.

(3) According to the present invention, a spectrum of ion energy can be generated by one pulse. In addition, multiple types of ion species can be used to achieve more uniform processing throughout the processing depth than single energy implants used in current continuous beam devices.

(4) The relatively high average ion output and transmitted ion power density, and consequently the high throughput rates achievable by the present invention, significantly improve ion implantation economics over current ion implantation methods. be able to.

The present invention provides chemical reactivity, catalytic activity, abrasion resistance, abrasion resistance, erosion resistance,
Resistance to dissimilar metal contact corrosion, pitting corrosion resistance, crack corrosion resistance, electron emission rate, adhesion of the next layer or coating, sliding friction coefficient, rolling friction coefficient, rolling contact fatigue resistance The surface characteristics can be modified by various methods, for example, by changing the sliding contact fatigue resistance, the light reflectance, the diffuse reflectance, the luminance, and the compressive residual stress of the surface by adjusting the surface stress.

In the above description, in order to make the present invention more understandable, specific materials, structures,
It gives a number of specific details, such as chemicals, processes, etc. However, the present invention can be practiced without relying on the specific details described above. In other words, the book does not describe well-known processes or materials in order not to obscure the stuffing unnecessarily.

In the text, only preferred embodiments of the invention and some examples of its application have been shown and described. The invention can be used in various combinations and environments,
It is to be understood that changes and modifications can be made within the spirit of the invention as expressed herein.

[Brief description of the drawings]

FIG. 1 illustrates the use of an intense ion beam pulse according to an embodiment of the invention to subject materials to rapid thermal cycling.

2A-B show voltage and current density waveforms according to one embodiment of the present invention. FIG. 2C shows a thermal cycle and its waveforms of a 1042 carbon steel formed using an energy level of 2.4 J / cm ² according to one embodiment of the present invention. FIG. 2D illustrates a thermal cycle and waveforms of 1042 carbon steel formed using different energy levels according to one embodiment of the present invention.

FIG. 3A is a micrograph showing an untreated copper surface. FIG. 3B is a micrograph showing the modified copper surface after treatment. FIG. 3C is a micrograph showing a modified copper surface according to one embodiment of the present invention.

FIG. 4 is a graph plotting temperature as a function of depth showing the evaporation of the zinc layer with the titanium layer above the zinc layer below the vaporization temperature.

FIG. 5 is a graph plotting temperature as a function of depth showing the evaporation of a partial surface layer before the outer surface layer has reached its vaporization temperature.

FIG. 6A shows a high gradient 17-4PH surface. FIG. 6B shows the same 17-4PH surface after treatment, showing a smoother surface with a reduced slope.

7A-D are micrographs showing a modified surface according to one embodiment of the present invention.

8A-B are microscopes showing tungsten cemented carbide surfaces before and after treatment according to one embodiment of the present invention.

9A-C are micrographs showing an alumina surface or an aluminum surface before and after treatment according to one embodiment of the present invention.

FIG. 10A is a micrograph showing 303 stainless steel processed according to one embodiment of the present invention. FIG. 10B is a micrograph showing 304 stainless steel processed according to one embodiment of the present invention.

FIG. 11 is a graph plotting temperature as a function of depth for 304 stainless steel.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY , CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP , KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZA, ZW (72) Inventor D. C. McIntyre, United States New Mexico 87111, Albuquerque, Northeast, Balsa Place 5909 (72) Inventor M. tea. Crawford United States of America New Mexico 87120, Albuquerque, Northwest, Frescacote 6816 (72) Inventor Thomas Earl. Rockner United States New Mexico 87111, Albuquerque, Northeast, Cargepino 3915 (72) Inventor. E. Voucher United States New Mexico 87112, Albuquerque, Northeast, Elizabeth Street 2310 (72) Inventor Eugene El. Know United States New Mexico 87107, Albuquerque, Northwest, Sandia Road 919 F-term (reference) 4K053 PA01 PA02 PA03 PA09 QA01 QA04 RA03 SA01 XA11

Claims (48)

[Claims] 1. A predetermined pulse repetition rate of at least 0.1 pulses per second, extracted from a magnetically confined anode plasma (MAP) ion source with little rotation relative to the surface of the material, and a pulse repetition rate of about 20 nanoseconds or less. and a step of irradiating a pulsed ion beam, a predetermined energy density in the range of about 0.01 J / cm ² to about 20 J / cm ² with respect to the surface having a predetermined pulse width in a range of 0.05 ms Applying a energy. 2. The method according to claim 1, wherein the step of applying comprises applying about 0.1 J / cm ^{2 to} about 1 J
The method of claim 1, wherein applies an energy having an energy density in the range of 0 J / cm ^2. 3. The method of claim 1 wherein said pulsed ion beam has a pulse repetition rate of at least about 0.5 pulses per second. 4. The method of claim 1, wherein said pulsed ion beam has an ion species purity of at least 60%. 5. The method of claim 1, wherein said pulsed ion beam modifies an area greater than 5 cm ² per pulse. 6. The method of claim 1, wherein the modification is cleaning, the surface includes a contaminant, and further comprising the step of partially cleaning the contaminant. 7. The cleaning step according to claim 6, further comprising the step of evaporating the contaminants by raising the surface to a temperature higher than the vaporization point of the contaminants and lower than the vaporization point of the surface material. the method of. 8. The method of claim 7, wherein the step of evaporating further comprises the step of promoting mixing of the contaminant with the surface material. 9. At least partially mixing the contaminant with the surface material by raising the temperature of the surface material to a temperature sufficient to melt the contaminant and at least one component of the surface material. 7. The method according to claim 6, further comprising:
The described method. 10. The method of claim 9, wherein said mixing step further comprises the step of raising the surface of said surface material to a temperature above the vaporization point of either said surface material or said contaminant. 11. The method of claim 1, wherein the modifying is purifying a contaminant-containing region in the surface, further comprising directing the contaminant to move toward an outer boundary of the surface. The method of claim 1. 12. The method of claim 11, further comprising the step of at least partially cleaning the contaminated surface by removing the displaced contaminant from the surface. 13. The method of claim 1, wherein the modifying is separating and / or removing the layer, further comprising the step of at least partially separating and / or removing the layer from the surface. 14. The method of claim 13, wherein said layer is adjacent to said surface. 15. The method according to claim 14, further comprising heating a surface adjacent to the layer to be separated and / or removed. 16. The method according to claim 13, further comprising the step of fusing a surface adjacent the layer to be separated and / or removed. 17. The method of claim 13, further comprising the step of evaporating a surface adjacent to the layer to be separated and / or removed. 18. The surface having an interface between a surface material and a layer of material adjacent to the surface material, at which the surface material and the material of the layer are at least partially mixed. The method of claim 1, further comprising the step of: 19. The method of claim 1, wherein said surface is crystalline and further comprising the step of heating and modifying said crystalline surface. 20. The method of claim 19, further comprising the step of converting said crystalline surface to an amorphous surface. 21. The method of claim 20, further comprising the step of coating said surface. 22. The method of claim 1, wherein the surface has a low density feature, further comprising the step of melting at least one material of the surface to reduce the low density feature of the surface. 23. The method of claim 22, further comprising the step of coating said treated surface. 24. The surface of claim 1, wherein the surface has a spatial gradient, further comprising the step of at least partially planarizing the surface to reduce the spatial gradient.
The described method. 25. The at least partially planarizing step further comprises at least partially melting at least one of the surface materials by increasing a temperature of the surface to a temperature above its melting point. The method of claim 24, wherein 26. The method of claim 25, wherein the step of at least partially planarizing further comprises the step of raising the temperature of the surface material to a temperature below its vaporization point. 27. The method of claim 26, wherein the step of increasing the temperature is performed substantially without removing material from the surface. 28. The method of claim 24, wherein the spatial gradient includes a protrusion, and wherein the planarizing step further comprises at least partially smoothing the surface by reducing the protrusion. Method. 29. The method of claim 24, wherein the spatial gradient includes a depression, and wherein the planarizing step further comprises at least partially smoothing the surface by reducing the depression. 30. The method of claim 1, further comprising the step of roughening at least a portion of said surface. 31. The method of claim 30, wherein the step of roughening comprises the step of at least partially melting at least one component of the surface. 32. The step of roughening comprises the step of at least partially evaporating at least one material on the surface by raising the temperature of the material to a temperature above its vaporization point. The described method. 33. The method according to claim 30, further comprising the step of forming a projection on the surface. 34. The method of claim 30, comprising forming a sharp spire on the surface. 35. The method of claim 1, further comprising heating said surface to a temperature below its melting point. 36. The method of claim 35, wherein said surface comprises at least two materials, and further comprising the step of raising the temperature of said surface to a temperature above the melting point of at least one of said materials. 37. The surface comprising a first material having a first melting point,
Adding a second material having a second melting point higher than the first melting point to the surface; and setting the temperature of the surface higher than or equal to the first melting point.
Raising the temperature to below the melting point of the method. 38. The surface comprises a first material having a first melting point,
2. The method of claim 1, further comprising: adding a second material having a second melting point to the surface; and increasing the temperature of the surface to a temperature higher than or equal to the first melting point. the method of. 39. The method of claim 3, further comprising the step of resolidifying said surface.
8. The method according to 8. 40. The method of claim 39, wherein said second material is a powder. 41. The method of claim 1, further comprising the step of generating a new or altered distribution of precipitates. 42. The method of claim 40, wherein said surface material comprises at least one metal or metal mixture. 43. The method according to claim 43, wherein the surface comprises at least a first material and a second material, wherein the step of raising the temperature of the surface to a temperature sufficient to at least partially remove the first material. The method of claim 1, further comprising: 44. The method of claim 43, wherein increasing the temperature comprises evaporating the first material. 45. The method of claim 44, wherein increasing the temperature comprises dissociating the first material. 46. The method of claim 1, further comprising heating the modified surface. 47. The method of claim 46, wherein said step further comprises tempering said surface. 48. The method of claim 46, wherein said heating step further comprises a hot isostatic pressing step.