CN1287930C - Water cooling electromagnetic copper type directional solidification method of titanium base alloy - Google Patents

Abstract

The present invention provides a method of water cooling electromagnetic copper type directional solidification of titanium master alloy, which relates to a method of the directional solidification of metal. The method of the traditional directional solidification difficultly obtains uniform cooling speed, and the productivity effect is low. The present invention has the method that the interior of a furnace body of an electromagnetic precision shaping and directional solidification device of a cold crucible is vacuumized, and the vacuum degree is 0.05 to 300 Pa; single-phase alternating current is conducted to a coil 3, and the power which is provided by a power supply is 40 to 70KW; in 4 to 16 minutes, a loading rod 1-1 and bed charges 1-2 make downward movement at 1.4 to 80 mu m/s so as to enable the bed charges to enter a crystallizer 9 arranged below the bed charges. The method of the present invention has the characteristics of continuous processes and short flow paths, and the present invention can especially and purposefully adjust the organization form of members under the processing conditions that heat transfer, mass transfer and flowage are appropriately controlled so as to reduce processing defects; the present invention is favourable for improving the comprehensive mechanical properties of alloy, and is especially favourable for the popularization and the application for important high-temperature mechanical properties in the process of high-temperature use.

Description

The water-cooled electromagnetic copper type directional freeze method of titanium-base alloy

Technical field:

The present invention relates to a kind of metal directional freeze method.

Background technology:

Directional solidification is under control foundry goods internal heat transfer, mass transfer and mobile condition, and metal (or crystal class material) can solidify or the process of crystallization along the fixed growth direction.The tissue signature of metal is the one group parallel column crystal parallel with the heat of solidification flow path direction after the directional solidification, if can suitably control the growth course of crystal grain, for example suppresses to examine outer next life, and then crystal can grow up to the crystalline structure that has only a crystal grain, is called monocrystal.This shows that directional solidification is at the special material processing technique that satisfies under unidirectional heat and the quality transmission primary condition.The development of this restricted solidification technology at present, development for modern solidification technology provides strong theory support on the one hand, for example all to depend on directional freeze method and come system research about many solidification phenomenons, on the other hand for the 26S Proteasome Structure and Function material of a large amount of excellent performances and practicability is provided on the engineering, as high temperature alloy aerial blade, semiconductor silicon electronic material, magnetostriction materials, crystallo-luminescence material, intermetallic compound and various Metal Substrate and inorganic composite materials or the like of orientation or monocrystalline.The superiority of directional solidification technique directly shows can control the freezing rate yardstick on a large scale, and promptly the cooldown rate of material can be by 10 during directional solidification ^-4K/S to 10 ⁴The K/S wide variation, therefore can be from preparing extremely slow statenchyma to adjustment on a large scale away from the ultra-fine of balance or metastable state structural state, again because the structural state and the performance indications of material are closely related, so directional solidification provides space widely for the material forming preparation process.The turbine and the guide vane of nearly all civilian and military advanced engine on the our times, the high temperature alloy manufacturing of all having adopted orientation and monocrystalline to solidify, improved the high temperature serviceability of material greatly, this fact has demonstrated fully the outstanding contributions of directional solidification technique.

Well-known titanium and alloy thereof are a class very active materials under the condition of high temperature especially melting condition, after World War II, titanium and alloy thereof progressively enter the practicability stage, this mainly is due to the excellent mechanics and physical property that titanium had, as low density, high specific strength and specific stiffness, high-melting-point, nonmagnetic, corrosion resistance and certain advantages such as hear resistance, in numerous areas extensive uses such as Aeronautics and Astronautics, naval vessel, automobile, building, chemical industry, have the title of the metal of titanium " steel " or 21st century.But the chemism of titanium is big, and processing, shaping and preparation be difficulty comparatively, is always restricting this class Development of Materials and application.The current processing mode that is used for titanium and alloy thereof mainly comprises: be out of shape rolling, machining, powder metallurgy and several big classes of ingot metallurgy, the pluses and minuses of several forming modes are as shown in table 1.

Several comparisons that are applicable to the preparation manufacturing process of titanium alloy of table 1

	Microscopic structure	Mechanical property	The member yardstick	Technological process
					Be out of shape rolling	Tissue odds is even, has the substructure that depends on rolling direction, texture and fault defective	The high temperature creep-resisting ability of alloy	Greatly, the mesoscale member, the micro-member processing difficulties	Complex technical process, sometimes relate to preliminary treatment, and the inappropriate material of phase constituent is difficult to processing to material
Powder metallurgy	The uniformity of tissue depends on material powder, multiple hole, not fine and close	Because gap pollution element (C, H, O) content is big, comprehensive mechanical property poor (plasticity is low)	In, the small scale member, the large-scale component processing difficulties	Relate to many processes such as powder preparation, prefabricated shaping and sintering process, the quality control of member is difficult
					Ingot metallurgy	Setting rate is slow, composition and phase segregation are bigger, organize thickly, exist shrinkage cavity loose	Because the interfacial reaction of existence and mold, the performance of alloy is lower	Large, medium and small yardstick member all is suitable for	The casting mold complicated process of preparation needs aftertreatment technologys such as high temperature insostatic pressing (HIP)
Machining	Depend on raw tissue	Depend on material performance and processing structure	Large, medium and small yardstick member all is suitable for	Utilization rate of raw materials is extremely low
					Directional solidification (this method)	Dense structure, no cavity blemish, can adjust structural state is equiax crystal, column crystal or monocrystalline	The comprehensive mechanical property of alloy, especially mechanical behavior under high temperature improve very big	In, the small scale member, after improving, be fit to the large scale member, but the member complexity is also not high	Technical process is carried out continuously, and flow process is short, and technology is simple relatively

Traditional directional solidification technique mainly is the difference that can realize thermograde according to apparatus for directional solidification or device, is divided into power and reduces method, rapid solidification method and liquid metal cooling method.The liquid metal cooling method is current comparatively practical directional solidification technique, owing to adopt the big normal temperature liquid metal of thermal capacity to cool off, the heat that is discharged in the ingot solidification is taken away rapidly, if liquid metal is directly contacted with ingot casting, improve the heat exchange condition, also can form very high thermograde at the solid liquid interface place.Liquid metal cooling device (LMC) is combined with Bridgman method, czochralski method or zone-melting process etc., developed and multiple directional solidification technique.But in traditional directional solidification, because the cooldown rate of test specimen is subjected to the restriction that solid phase end heat is derived speed, be difficult to obtain uniform cooldown rate, again because in order to obtain the oriented freezing organization of even refinement, greatly reduce drawing velocity, the problem that production efficiency is low is difficult to solve.

For the refinement oriented freezing organization, reduce solidifying segregation and improve freezing rate, Recent study various novel directional solidification techniques.Comprise: the high gradient directional freeze method, the high undercooling directional freeze method, the electromagnetic shaping directional freeze method of special alloy, the continuous casting of single crystal directional freeze method, crystal orientation control directional freeze method, the directional freeze method of high tough ceramic material, said method all can not be used for the directional solidification of titanium-base alloy, this is because the high activity of titanium alloy self, the problem of a key is exactly how to avoid the pollution of container material (crucible and casting mold) to alloy when it is carried out directional solidification, so that keep the accuracy of alloy composition, eliminate the erosion of physics and chemical field trash to directional solidification castings, guarantee that alloy still has higher physics and mechanical property after the directional solidification preparation, be suitable for the application in special industry equipment and occasion.

Electromagnetic hydroimechanics is laid a good foundation for illustrating the various actions of fluid under the effect of magnetic field by electromagnetic field is combined with hydrodynamics.According to Maxwell's electromagnetic theory, alternating electromagnetic field can transform the energy of self in continuous media, the metal or alloy that is flow regime under the high temperature, because electrical conductivity height, magnetic resistance are easy to be subjected to the Joule heat effect and the Lorentz force action in magnetic field for a short time, just occurred in industry like this that electromagnetic induction fusing, electromagnetic agitation, melt shape control, drivings/suppression fluid are mobile, the metal technology in electromagnetic processing of various ways such as suspension and atomizing.

At present, utilize the electromagnetic continuous-casting technology of electromagnetic hydroimechanics principle to obtain very great development, its principle is: after induction produces eddy current, eddy current and magnetic field force interact, produce the electromagnetic push that points to molten metal inside, when thrust during greater than the molten metal static pressure liquid metal pushed away inductor and formed fluid column, cooling and pull by to lower metal have formed continuous casting process.Successful Application is in the no mould continuous casting of aluminium alloy for electromagnetic casting technology (EMC), and the annual aluminium alloy ingot blank that relies on this method to produce accounts for more than 30% of Gross World Product.In the iron and steel billet was produced, the effect that people also begin to utilize electromagnetic field to replace crystallizer made metal forming, the blemish that causes to eliminate the relative friction with crystallizer of strand.

Yet ferrous materials density is big, and only under the electromagnetic field effect of macro-energy very, electromagnetic push could make the metal fluid column keep side upright, and the alternating electromagnetic field in the reality can not produce high like this energy.General Electric Apparatus Co.(U.S.A.) in 1984 has declared and applied alternating electromagnetic field outside crystallizer, rely on crystallizer wall to bear the patent of the so-called soft-contact mould of part metals hydrostatic pressure power, bear the molten metal static pressure jointly by electromagnetic push and crystallizer wall, reduced dynamic pressure, the iron and steel billet material that has excellent surface quality for production is laid a good foundation, and is called as the soft-contact electromagnetic continuous casting technology.After this, this technology is in country such as the U.S., France, Japan, Korea S and domesticly all be rapidly developed, and adopt the soft-contact mould technology to make continuous casting billet quality obviously improve, and used electromagnetic push is much smaller than the electromagnetic force of no mould continuous casting electromagnetic.

The development of the soft contact continuous casting technology of electromagnetism is improving the continuous casting steel billet quality, enhances productivity and the shortened process aspect has clear superiority, provides technical guarantee for producing the zero defect strand.Because succeeding in developing of ferrous materials soft-contact electromagnetic continuous casting technology, driven the development of the electromagnetic field process technology of material, enter after the nineties in last century, this technology also develops to the direction of no meniscus continuous casting, it is hot tap continuous casting electromagnetic technology, by top hot topping is set at continuous cast mold, keep metal liquid measure and temperature constant, simultaneously apply the electromagnetic field of high frequency at crystallizer/liquid metal/hot topping point of interface place, effectively improve the initial solidification condition of strand, control the initial position of solidifying of molten metal, further improved slab surface quality.

Multi-functional cold crucible electromagnetism Accurate Shaping and device for directionally solidifying that the applicant declares, in the body of heater of this device, be provided with charge bar, charge bar comprises loading rod and unloading rod (unloading rod claims bed material again), loading rod is connected with upper motor by last feeding rod, unloading rod passes through down, and pumping rod is connected with lower motor, the described lower end of pumping rod down also is connected with the swing angle system, outside at charge bar, the inside of induction coil is provided with cold-crucible, body of heater is a double-decker, below the inside of body of heater be unloading rod under be provided with the directional solidification crystallizer, in the inside of directional solidification crystallizer coolant metal is housed.

Summary of the invention:

The object of the present invention is to provide a kind of and cold crucible electromagnetism Accurate Shaping and device for directionally solidifying to be used, can process titanium and alloy thereof, have process continuously and flow process lack the water-cooled electromagnetic copper type directional freeze method of the titanium-base alloy of characteristics, in the body of heater of cold crucible electromagnetism Accurate Shaping and device for directionally solidifying for being evacuated down to 0.05～1Pa earlier, after return applying argon gas to 300～400Pa, body of heater inside is provided with charge bar 1, charge bar 1 is provided at an outer portion with water-cooled copper type 2, the outside of water-cooled copper type 2 is provided with induction coil 3, the number of turn of coil 3 is 2～4 circles, described charge bar 1 comprises loading rod 1-1 and bed material 1-2, after loading rod 1-1 and bed material 1-2 send into the induction range of coil 3, bed material stretches into 50～70mm in the copper type, it is 20kHz that coil 3 feeds single-phase alternating current, a kind of in three kinds of frequencies of 50kHz and 100kHz, it is 40～70KW that power supply applies power, after 4～16 minutes, loading rod 1-1 and bed material 1-2 are moved downward with the speed of 1.4～80 μ m/s, and bed material is entered in the setting crystallizer 9 thereunder get final product.The present invention is directed to titanium alloy, in the water-cooled copper type,, constitute the continuous directional solidification system by the two combines with electromagnetism progressive forming and directional solidification technique.Its induction coil by having induction heating function is carried out fusing, overheated, constraint shapes, is shaped and solidified the metal that needs directional solidification, and these processes all are to carry out in the split-type water-cooled copper type that can not pollute metal.Metal liquid temperature gradient of solid-liquid interface of required maintenance in process of setting is by being obtained by the low temperature in the room temperature liquid metal low-melting-point metal liquid of the high-temperature of superheated melt below extending in the copper type, by keeping stable setting rate, thereby make solid liquid interface keep stable, will keep carrying out smoothly of this continuous, directed process of setting like this.Method of the present invention and a few class are applicable to that the processing method of titanium and alloy thereof relatively has the characteristics that process is continuous and flow process is short, especially suitable control conduct heat and mass transfer and mobile processing conditions under can autotelic adjustment member tissue morphology, reduce manufacturing deficiency, help improving the comprehensive mechanical property of alloy, particularly use very important mechanical behavior under high temperature for high temperature.The present invention has following significance for this reason: developed high-quality at advanced materials such as titanium alloys, efficient, safe, special and material forming and technology of preparing cheaply, advanced, the special method that shapes of development simultaneously is also for reducing production costs and the compatibility of improvement and living environment is laid a good foundation.

Description of drawings:

Fig. 1 is the structural representation of the inventive method institute coupling apparatus, and Fig. 2 is water-cooled copper type 2 and water pipe 8 syndeton schematic diagrames, and Fig. 3 is the A-A cutaway view of Fig. 2, and Fig. 4 is a syndeton schematic diagram of going up feeding rod 21 and loading rod 1.

The specific embodiment:

The specific embodiment one: the course of work of present embodiment is as follows: with reference to Fig. 1, body of heater 4 is installed on the support frame 6 by bolt, support frame 6 is level and stably is fixed on the ground with foundation bolt 6-1 connection; At body of heater 4 inner bottom parts two groups of circulating water channels 7 are arranged, circulating water channel 7 is communicated with body of heater 4 with water pipe 8, and the other end of water pipe 8 is communicated with water-cooled copper type 2, thereby the water route of body of heater is communicated with the water route of water-cooled copper type; By being connected of water pipe 8 and circulating water channel 7, can also play a supporting role to water-cooled copper type 2; The crystallizer 9 of inner water flowing cooling adopts welding manner to be fixed on the middle position, bottom of body of heater 4, the outside of body of heater 4 is stretched in its bottom, for the directional solidification of being implemented provides the pressure cooling effect, its cooling effect is that the low-melting alloy cooling fluid 10 by its inner splendid attire realizes, low-melting alloy cooling fluid 10 is bianry alloy liquid or ternary alloy three-partalloy liquid, described bianry alloy liquid is Ga-24.5%, In-75.5%, described ternary alloy three-partalloy liquid is Ga-25%, In-13%, Sn-62%, perhaps ternary alloy three-partalloy liquid is Ga-21%, In-16%, Sn-63%.In the body of heater of cold crucible electromagnetism Accurate Shaping and device for directionally solidifying for being evacuated down to 0.05～1Pa earlier, after argon gas to the 300～400Pa that recoils, body of heater inside is provided with charge bar 1, charge bar 1 is provided at an outer portion with water-cooled copper type 2, the outside of water-cooled copper type 2 is provided with induction coil 3, the number of turn of coil 3 is 2～4 circles, described charge bar 1 comprises loading rod 1-1 and bed material 1-2, after loading rod 1-1 and bed material 1-2 send into the induction range of coil 3, bed material stretches into 50～70mm in the copper type, coil 3 feeds single-phase alternating current, it is 40～70KW that power supply applies power, after 4～16 minutes, loading rod 1-1 and bed material 1-2 are moved downward with the speed of 1.4～80 μ m/s, and bed material is entered in the setting crystallizer 9 thereunder get final product.The center of crystallizer 9 has the material bar that moves of internal water shell type recirculated water cooling promptly to descend pumping rod 11, following pumping rod 11 is connected with crystallizer 9 bottom movable sealings, when directional solidification, move downward, play the effect that the alloy billet that will solidify moves apart the hot-zone part 18 of water-cooled copper type 2; Moving up and down of following pumping rod 11 relies on the servomotor 13 that is fixed on the base 12 to drive, motor 13 drives connected threaded rod 14 motions, threaded rod 14 drives connected synchronizing bar 15 motions, and driving down by synchronizing bar 15 again, pumping rod 11 moves up and down; The lower end of following pumping rod 11 is connected with swing angle motor 17 on being fixed on base 16, adjusts pattern angles and pattern shape by swing angle motor 17 and can drive down pumping rod 11 and do the low-angle rotation.

Water-cooled copper type 2 is formed through machining by the red copper billet, interior bone, the diameter of interior bone is 30mm, as shown in Figure 2, water-cooled copper type 2 is inside and outside straight joint formula splitted structure, and the width L in the slit 34 between adjacent two lobes is 0.3-0.8mm, fills the mica material of low conductivity in the slit 34 and makes electric insulation between lobe and the lobe, but whole short transverse is not run through in slit 34, extends to from top to bottom till 2/3rds to 3/4ths places; The thin-wall copper pipeline circle 3 of the spiral inner water flowing cooling of two to four circles closely is wrapped in the outer surface of water-cooled copper type 2, when coil 3 inside feed the alternating current of the different frequency of being supplied with by power supply, can excite alternating magnetic field, and pass through water-cooled copper type distinguish wall to diffusion inside, produce the needed hot-zone 18 of process, because the supply frequency difference is very big to the influence of the Energy distribution of hot-zone, this method has been selected a kind of in 20kHz, 50kHz and three kinds of frequencies of 100kHz; Stable in order to guarantee the hot-zone in addition, coil 3 extends about the half turn distance to the not parting zone of copper type 2; Thin-wall copper pipeline circle 3 outward extending two is connector side by side, be fixed to by insulating disc 19 by nut and fluid sealant packing ring and be fixed on the electrode contact 20 on the body of heater 4, coil 3 and water-cooled copper type 2 will keep the perpendicularity requirement when installing, and be concentric with charge bar 1 to guarantee; Last feeding rod 21 is fixed on the synchronizing bar 22, synchronizing bar 22 is connected with motor 23, thereby under the drive of the adjustable digital servomotor 23 of feeding speed, finish the feeding campaign, in order to guarantee that thermal deformation does not take place feeding rod 21 in the feeding process, the described feeding rod 21 of going up adopts jacket structure for water, be connected with movable sealing between last feeding rod 21 and the body of heater 4, motor 23 is fixing by the support 24 that is welded on the body of heater; During work, at first bed material 1-2 is sent in the water-cooled copper type 2, the initial material 35 that dissolves was welded together with bed material 1-2 and formed end material rod this moment, dissolve the material 35 dissolve the back formed diameter be 25～28mm, by last feeding rod 21 loading rod 1-1 is sent in the water-cooled copper type 2 again, enter in copper tube coil 3 scopes, but with dissolve material and 35 reserve appropriate gap, the time that loading rod 1-1 and bed material 1-2 enter coil 3 induction ranges is, bed material 1-2 minute enters prior to loading rod 1-15～10, and bed material stretches into 50～70mm in the copper type; After feeding the high frequency single-phase alternating current of power supply in the copper tube coil 3, under the electromagnetic induction effect, by distinguish water-cooled copper type 2 inside, can on fuel rod 1-1 and bed material 1-2, produce Joule heat and electromagnetic push, thereby form the top fusing, the effect of bottom magnetic force constraint, molten drop drops on the melt of bed material 1-2 and restrained back hot forming, keep after 4～16 minutes, last feeding rod 21, following pumping rod 11 moves downward under the drive of motor, the speed that last feeding rod 21 and following pumping rod 11 move downward is 1.4～80 μ m/s, and the speed of last feeding rod 21 is according to pumping rod 11 is definite down; Melt solidifies gradually, and following pumping rod 11 drive bed material 1-2 move downward to enter and keep thermogrades in the crystallizer 9, thereby obtain good oriented freezing organization; For the lubricity of improving forming process and the Quench that weakens water-cooled copper type 2, when processing is prepared, evenly apply flux material at inwall, used flux is binary flux or ternary flux or quaternary flux, by weight percentage, binary flux is CaO-70%, CaF ₂-30%; Ternary flux is CaO-70%, CaF ₂-10%, CaCl ₂-20%; Quaternary flux is CaO-70%, CaF ₂-10%, CaCl ₂-5%, MgCl ₂-15%.With reference to Fig. 4, two-way blind hole coupling nut 25 is by last screw thread, the mode of following pin will go up feeding rod 21 and loading rod 1-1 couples together, upper end and the last feeding rod 21 that are two-way blind hole coupling nut 25 are connected by helicitic texture, at the side of coupling nut 25 perforate 25-1, hole 25-1 can pass through the thermocouple wire 26 of thermometric smoothly, and thermocouple wire 26 exits are fixed on the patchboard 27 and stretch out and connect with temperature measuring equipment by compensating wire in the stove 28 and stove outer conductor 29; The lower end of two-way blind hole coupling nut 25 is connected with loading rod 1-1 by pin 36, and pin 36 all is the loose fit mode with nut 25, loading rod 1-1, can guarantee that like this loading rod 1-1 has the moving space of enough strings when entering water-cooled copper type 2; The flange port 4-1 of body of heater 4 vacuumizes for furnace chamber and the anti-protective gas that fills provides passage, and vacuum is finished by the vacuum system of routine; When needing, fill protective gas in body of heater, protective gas is by the gas bottle air feed; The ring flange 31 that is used for fixing multiplexed signal sampling terminal 30, the sealing of employing O-ring seal also is fixed on the body of heater 4; All water cooling systems that the inventive method needs all are connected with water tank by water pipe, and supply water by water pump; Watch window 32 is arranged at the top of body of heater 4, and inner clamping thermostable transparent quartz glass 33 can be observed heating state in the stove.

Operation principle of the present invention comprises electromagnetic confinement and two aspects of directional solidification, aspect electromagnetic confinement, high frequency magnetic field is with the raw material induction melting, and formation hump, by feeding rod speed control hump height, increase power the melt overheat degree is increased, and reduce with copper type inwall contact area, reduce the scull effect, make melt be in stable form; Aspect directional solidification, because the superhigh intensity of liquid metal cooling, form big temperature gradient distribution, electromagnetic field stirs molten matter is evenly distributed, the soft Contact Effect of electromagnetic confinement, make the side direction heat radiation be inhibited, form the solid liquid interface of planar interface at last, obtain the pollution-free directional solidification of water-cooled copper type at last.

The specific embodiment two: present embodiment is implemented the directional solidification process for adopting the inventive method to titanium-base alloy, alloying component is Ti-6wt%Al-4wt%V, this is a kind of general titanium alloy, accounts for more than 90% of present commercial titanium alloy use amount, is 1mm/min in speed, power is under the condition of 48KW this alloy to be implemented directional solidification, sample is vertical to be dug to obtaining, and after the polishing corrosion, whole planing surface has three big columnar grains, the freezing interface is a planar interface, can obtain oriented freezing organization.Tensile strength of alloys after the directional solidification changes little, and percentage elongation brings up to 12.7% by 8.2%.

The specific embodiment three: present embodiment is implemented the directional solidification process for adopting the inventive method to another kind of titanium-base alloy, alloying component is the Ti-36wt%Al alloy, this is a compound-material between a kind of titanium-based metal that contains a large amount aluminium, belong to novel light high-temperature-resistant structure material, in high temperature parts such as aero-engine, have a wide range of applications, at drawing velocity is 0.2mm/min, when power is 48KW this compound-material is implemented directional solidification, also can obtain oriented freezing organization, explanation can obtain to have the oriented freezing organization that solidifies feature under low discharging speed situation.Tensile strength is brought up to 287MPa by the 245MPa of as cast condition, and percentage elongation brings up to 0.35% by 0.1%.

The specific embodiment four: present embodiment is implemented the directional solidification process for adopting the inventive method to titanium-base alloy, alloying component is Ti-6wt%Al-4wt%V, this is a kind of general titanium alloy, accounts for more than 90% of present commercial titanium alloy use amount, is 1mm/min in speed, power is under the condition of 56KW this alloy to be implemented directional solidification, sample is vertical to be dug to obtaining, and after the polishing corrosion, whole planing surface has three big columnar grains, the freezing interface is a planar interface, can obtain oriented freezing organization.Tensile strength of alloys after the directional solidification changes little, and percentage elongation brings up to 12.7% by 8.2%.

The specific embodiment five: present embodiment is implemented the directional solidification process for adopting the inventive method to titanium-base alloy, alloying component is Ti-6wt%Al-4wt%V, this is a kind of general titanium alloy, accounts for more than 90% of present commercial titanium alloy use amount, is 1mm/min in speed, power is under the condition of 66KW this alloy to be implemented directional solidification, sample is vertical to be dug to obtaining, and after the polishing corrosion, whole planing surface has three big columnar grains, the freezing interface is a planar interface, can obtain oriented freezing organization.Tensile strength of alloys after the directional solidification changes little, and percentage elongation brings up to 12.7% by 8.2%.

Claims (7)

1. the water-cooled electromagnetic copper type directional freeze method of a titanium-base alloy, it is characterized in that in the body of heater of cold crucible electromagnetism Accurate Shaping and device for directionally solidifying for being evacuated down to 0.05～1Pa earlier, after return applying argon gas to 300～400Pa, body of heater inside is provided with charge bar (1), charge bar (1) is provided at an outer portion with water-cooled copper type (2), the outside of water-cooled copper type (2) is provided with induction coil (3), the number of turn of coil (3) is 2～4 circles, described charge bar (1) comprises loading rod (1-1) and bed material (1-2), after loading rod (1-1) and bed material (1-2) are sent into the induction range of coil (3), bed material stretches into 50～70mm in the copper type, it is 20kHz that coil (3) feeds single-phase alternating current, a kind of in three kinds of frequencies of 50kHz and 100kHz, it is 40～70KW that power supply applies power, after 4～16 minutes, loading rod (1-1) and bed material (1-2) speed with 1.4～80 μ m/s is moved downward, and bed material is entered in the setting crystallizer 9 thereunder get final product.

2. the water-cooled electromagnetic copper type directional freeze method of titanium-base alloy according to claim 1, it is characterized in that described bed material (1-2) upper end molten have dissolve material (35), the described material (35) that dissolves dissolves afterwards that formed diameter is 25～28mm.

3. the water-cooled electromagnetic copper type directional freeze method of titanium-base alloy according to claim 1, it is characterized in that the time that loading rod (1-1) and bed material (1-2) enter coil (3) induction range is that bed material (1-2) entered prior to loading rod (1-1) in 5～10 minutes.

4. according to the water-cooled electromagnetic copper type directional freeze method of claim 1,2 or 3 described titanium-base alloys, it is characterized in that described water-cooled copper type (2) is inside and outside straight joint formula splitted structure, the internal diameter size of described copper type is 30mm, the width (L) in the slit (34) between adjacent two lobes is 0.3-0.8mm, fill insulant in the slit (34), the height (K) of slit (34) is 2/3rds to 3/4ths of a water-cooled copper type height (H).

5. the water-cooled electromagnetic copper type directional freeze method of titanium-base alloy according to claim 4 is characterized in that the installation site between coil (3) and the water-cooled copper type (2) is, coil (3) extends the half turn distance to the not parting zone of water-cooled copper type (2) lower end.

6. the water-cooled electromagnetic copper type directional freeze method of titanium-base alloy according to claim 4, it is characterized in that evenly applying flux material at the inwall of described water-cooled copper type (2), used flux is binary flux or ternary flux or quaternary flux, by weight percentage, binary flux is CaO-70%, CaF ₂-30%; Ternary flux is CaO-70%, CaF ₂-10%, CaCl ₂-20%; Quaternary flux is CaO-70%, CaF ₂-10%, CaCl ₂-5%, MgCl ₂-15%.

7. according to the water-cooled electromagnetic copper type directional freeze method of claim 1,2 or 3 described titanium-base alloys, it is characterized in that being equipped with in the described crystallizer (9) low-melting alloy cooling fluid (10), described low-melting alloy cooling fluid (10) is bianry alloy liquid or ternary alloy three-partalloy liquid, and described bianry alloy liquid is Ga-24.5%, In-75.5%, described ternary alloy three-partalloy liquid is Ga-25%, In-13%, Sn-62%, perhaps ternary alloy three-partalloy liquid is Ga-21%, In-16%, Sn-63%.

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