A gradient structure platinum alloy material and its preparation method and finished product

Abstract

The present invention relates to a platinum alloy material with a gradient structure, a preparation method and a finished product thereof. The platinum alloy material is composited with platinum alloy material layers in different states by adopting a powder metallurgy hot isostatic pressing sintering technology. By adjusting the composition, grain size, thickness and relative order of each layer of material, while having processing performance similar to that of pure platinum material and surface corrosion resistance similar to that of dispersion-strengthened platinum material, the thickness of the interlayer welding area is further increased, the interlayer composite strength is greatly improved, and the platinum alloy material is guaranteed not to be delaminated during processing, welding and use, the reliability of the material is significantly improved, and composite defects are greatly reduced. The material has broad market application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation and processing of platinum alloy materials, and specifically relates to a gradient structure platinum alloy material, and a preparation method and a finished product thereof. Background Art

[0002] Platinum alloy materials are widely used in the manufacture of glass product production equipment for ultra-high temperature service conditions, such as glass fiber bushings, platinum crucibles, etc. Under ultra-high temperature (>1200℃) service conditions, platinum alloys will experience multiple tests such as erosion caused by glass liquid scouring, electric current heating shock during rapid heating, thermal fatigue caused by the flow of external heat transfer media, and static creep stress caused by the gravity of glass liquid and alloy itself.

[0003] Since alloy grain boundaries are the concentrated areas of internal dislocations, defects and impurities, the above external factors will first act on the alloy grain boundaries, causing corrosion and tensile creep, resulting in grain boundary depression. When corrosion and creep depressions are superimposed and penetrate the grains, grain boundary cracks will occur, and eventually the cracks will extend to material cracking, causing microcracks or even local cracking in platinum products.

[0004] A series of reinforced platinum alloy materials have been developed to meet this challenge. At present, dispersion strengthening is one of the effective means to improve the high-temperature creep resistance of platinum alloy materials. Platinum and platinum-rhodium alloy dispersion-strengthened materials prepared with zirconium oxide, yttrium oxide, etc. as strengthening agents are widely used in glass product manufacturing equipment used under ultra-high temperature conditions. This is achieved by introducing dispersed phase strengthening elements such as zirconium and yttrium into platinum alloys, generating nano-scale internal oxidation second phase particles in the platinum matrix and dispersing and precipitating them, and using the dispersion strengthening effect and solid solution strengthening effect of the second phase to hinder dislocation movement and recrystallization processes, so as to obtain significant high-temperature strengthening effects. Because dispersion-strengthened platinum alloy materials have strong high-temperature creep resistance and high-temperature grain growth inhibition capabilities, platinum alloy equipment produced using this material has better high-temperature deformation resistance and erosion resistance, and the service life of the equipment is significantly improved compared to non-reinforced materials.

[0005] However, due to the inherent characteristics of dispersion-strengthened materials, the toughness and welding performance of dispersion-strengthened platinum alloy materials are significantly reduced compared to non-strengthened materials. Abnormal cracking often occurs during rolling, welding and equipment use, resulting in material scrapping and equipment failure, seriously affecting the stability of related production lines. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the inventors have found through research that a multi-layer platinum alloy material with a gradient structure of multiple layers of composite materials can be manufactured by using powder metallurgy hot isostatic pressing sintering technology to obtain the required performance.

[0007] Specifically, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a gradient structure platinum alloy material, which is composited by two to multiple layers of platinum alloy materials in different states, wherein the platinum alloy material is selected from one or more of dispersion strengthened platinum material, pure platinum material, dispersion strengthened platinum-rhodium alloy material, and pure platinum-rhodium alloy material.

[0008] Furthermore, in the gradient structure platinum alloy material described in the present invention, the rhodium content in the dispersion strengthened platinum-rhodium alloy material is 0.1%wt to 30%wt, and the rhodium content in the pure platinum-rhodium alloy material is 0.1%wt to 30%wt, calculated as a percentage by mass.

[0009] Furthermore, in the gradient structure platinum alloy material described in the present invention, the thickness of each layer of the platinum alloy material is ≥5 μm.

[0010] Furthermore, in the gradient structure platinum alloy material described in the present invention, the grain size of each layer of the platinum alloy material is ≥0.5 μm.

[0011] In another aspect, the present invention provides a method for preparing the gradient structure platinum alloy material as described above, comprising the following steps: Step 1) Powder batching: weigh several portions of platinum alloy powder in different states according to the material formula; Step 2) Filling the powder into the mold: According to the material formula, the platinum alloy powders in different states weighed in step 1) are layered and filled into a two-layer or multi-layer platinum mold, and different layers are separated by movable partitions; then the platinum mold filled with powder is placed on a vibration table, the vibration table is turned on to vibrate the powder and then the partition is removed; Step 3) hot isostatic pressing: the platinum mold processed in step 2) is sealed, and after vacuum pretreatment, the whole is placed in a hot isostatic pressing device for pressing to obtain a composite alloy blank; Step 4) diffusion treatment: after the blank obtained in step 3) is turned to remove the surface platinum mold, it is placed in a high-temperature furnace for thermal diffusion treatment to obtain a multi-layer alloy material; Step 5) calendering: the composite material obtained in step 4) is forged, rolled, rolled into strips, and drawn to obtain plates, rods, or wires.

[0012] Furthermore, in the method for preparing the gradient structure platinum alloy material described in the present invention, the platinum alloy powder in different states in step 1) is selected from one or more of dispersion strengthened platinum powder, pure platinum powder, dispersion strengthened platinum-rhodium alloy powder, and pure platinum-rhodium alloy powder.

[0013] Furthermore, in the preparation method of the gradient structure platinum alloy material described in the present invention, the rhodium content in the dispersion strengthened platinum-rhodium alloy powder is 0.1%wt~30%wt, and the rhodium content in the pure platinum-rhodium alloy material is 0.1%wt~30%wt, calculated as a percentage by mass.

[0014] Furthermore, in the method for preparing the gradient structure platinum alloy material of the present invention, the particle size range of the platinum alloy powder in different states in step 1) is 200nm≤D50≤200μm.

[0015] Furthermore, in the method for preparing the gradient structure platinum alloy material of the present invention, the thickness of each layer of the multi-layer alloy material described in step 4) accounts for 5%-95% of the total thickness of the material.

[0016] Furthermore, in the preparation method of the gradient structure platinum alloy material of the present invention: the processing parameters of the hot isostatic pressing in step 3) are: a holding pressure of 100-200 MPa, a holding temperature of 1200-1700° C., and a holding time of 0.5-4 h; The parameters of the diffusion treatment in step 4) are: 400° C. for 2 h, 800° C. for 5 h, 1100° C. for 5 h, 1400° C. for 10 h, and then taken out and air-cooled.

[0017] The advantages and beneficial effects of the present invention are: The gradient structure platinum alloy material prepared by the present invention is composited with different kinds of platinum alloy materials, and a variety of composite functions are obtained by adjusting the composition, grain size, thickness and relative order of each layer of material; the composite material has processing performance similar to that of pure platinum material and surface corrosion resistance similar to that of dispersion-strengthened platinum material.

[0018] 2) The present invention uses powder metallurgy hot isostatic pressing sintering technology to achieve the composite of different layers of materials, and performs full-area pressure sintering between layers at the grain scale, which greatly reduces composite defects. In addition, due to the spatial overlap of powder particles on both sides of the interface of different layers during the manufacturing process, the thickness of the interlayer welding area is further increased, which greatly improves the interlayer composite strength, ensures that the material does not delaminate during processing, welding and use, and significantly improves the reliability of the material, especially overcoming the defect of being unable to ensure the interlayer bonding strength caused by the strong anti-welding ability of the surface of the dispersion-strengthened material in conventional diffusion composite and welding composite methods. DETAILED DESCRIPTION

[0019] The technical scheme of the present invention is specifically described below in conjunction with the embodiments. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention. The raw materials, reagents, equipment, etc. used in the following embodiments are all commercially available or conventionally available.

[0020] In a specific implementation manner, in the gradient structure platinum alloy material described in the present invention, the thickness of each layer of platinum alloy material can be adjusted according to demand, and the thinnest can reach 5 μm.

[0021] In a specific embodiment, in the gradient structure platinum alloy material described in the present invention, the grain size of each layer of platinum alloy material can be adjusted according to demand, and the minimum can be 0.5 μm.

[0022] In a specific embodiment, in the gradient structure platinum alloy material described in the present invention, the relative order of different layers of the material can be adjusted according to needs.

[0023] In a specific embodiment, among the parameters involved in the preparation method of the present invention, the temperature tolerance is ±50°C, and the time tolerance is ±30min.

[0024] Example 1 A gradient structure platinum alloy material and a finished product thereof, wherein the preparation method thereof comprises the following steps: Step 1) Powder ingredients: weigh 2 parts of dispersion-strengthened platinum powder (particle size D50≈20μm), 500g each. Weigh 1 part of pure platinum powder (particle size D50≈100μm), weighing 9kg; Step 2) Fill the powder into the mold: The powder weighed in step 1) is filled into the three-layer platinum mold in layers, and the filling order is: dispersion-strengthened platinum powder-pure platinum powder-dispersion-strengthened platinum powder. The different layers are separated by movable partitions. Then place the platinum mold filled with powder on a vibration table, turn on the vibration table, set the vibration time to 5 minutes, and remove the partition after the powder is vibrated; Step 3) Hot isostatic pressing: Seal the platinum mold processed in step 2), put it into the hot isostatic pressing equipment as a whole after vacuum pretreatment, set the holding temperature to 1400℃, the holding pressure to 150MPa, the holding time to 0.5h, and start the pressing program. After the program is completed, the composite alloy billet is taken out after the equipment cools down; Step 4) diffusion treatment: the blank obtained in step 3) is turned to remove the surface platinum mold and then placed in a high-temperature furnace, the temperature is set to 1400° C., the heat preservation time is 2 hours, and thermal diffusion treatment is performed to obtain a composite alloy material; Step 5) Rolling processing: The composite alloy material prepared in step 4) is forged and then rolled into a plate with a thickness of 1.0 mm to obtain a finished product.

[0025] The plate prepared in this embodiment is further used to make a platinum crucible, which shows processing and welding properties comparable to those of pure platinum material, and surface corrosion resistance comparable to that of dispersion-strengthened platinum.

[0026] Example 2 A gradient structure platinum alloy material and a finished product thereof, wherein the preparation method thereof comprises the following steps: Step 1) Powder ingredients: weigh 9.5 kg of dispersion-strengthened platinum powder (particle size D50≈20 μm) and 0.5 kg of pure platinum powder (particle size D50≈100 μm); Step 2) Fill the powder into the mold: The powder weighed in step 1) is filled into two layers of platinum molds in layers, and the different layers are separated by movable partitions. Then the platinum mold filled with powder is placed on a vibration table, the vibration table is turned on, the vibration time is set to 10 minutes, and the powder is vibrated and the partition is removed; Step 3) Hot isostatic pressing: Seal the platinum mold processed in step 2), put it into the hot isostatic pressing equipment as a whole after vacuum pretreatment, set the holding temperature to 1500℃, the holding pressure to 190MPa, the holding time to 2h, and start the pressing program. After the program is completed, the composite alloy billet is taken out after the equipment cools down; Step 4) diffusion treatment: the blank obtained in step 3) is turned to remove the surface platinum mold and then placed in a high-temperature furnace at a temperature of 1500° C. for 2 h for thermal diffusion treatment to obtain a composite alloy material; Step 5) Rolling processing: The composite alloy material obtained in step 4) is forged and then rolled into a plate with a thickness of 1.5 mm to obtain a finished product.

[0027] The plate prepared in this embodiment is further used to make a glass fiber leak plate bottom plate, wherein the pure platinum layer faces upward and the dispersion strengthened platinum layer faces downward. At this time, the pure platinum layer provides solder for leak nozzle welding, significantly improves the leak nozzle welding quality, reduces welding microcracks, and at the same time, the dispersion strengthened platinum layer provides good high temperature strength for the bottom plate.

[0028] Example 3 A gradient structure platinum alloy material and a finished product thereof, wherein the preparation method thereof comprises the following steps: Step 1) Powder ingredients: weigh 0.5 kg of dispersion-strengthened platinum-rhodium 10 alloy powder (particle size D50≈50 μm), and weigh 9.5 kg of pure platinum-rhodium 10 alloy powder (particle size D50≈50 μm); Step 2) Fill the powder into the mold: The powder weighed in step 1) is filled into two layers of cylindrical platinum molds in the form of concentric circles. The inner circle is filled with pure platinum-rhodium 10 alloy powder, and the outer circle is filled with dispersion-strengthened platinum-rhodium 10 alloy powder. The two layers are separated by a movable cylindrical partition. Then place the platinum mold filled with powder on a vibration table, turn on the vibration table, set the vibration time to 10 minutes, and remove the partition after the powder is vibrated; Step 3) Hot isostatic pressing: Seal the platinum mold processed in step 2), put it into the hot isostatic pressing equipment as a whole after vacuum pretreatment, set the holding temperature to 1600℃, the holding pressure to 200MPa, the holding time to 4h, and start the pressing program. After the program is completed, the composite alloy billet is taken out after the equipment is cooled; Step 4) diffusion treatment: the blank obtained in step 3) is turned to remove the surface platinum mold and then placed in a high-temperature furnace, the temperature is set to 1600° C., the heat preservation time is 2 hours, and thermal diffusion treatment is performed to obtain a composite alloy material; Step 5) rolling processing: the composite alloy material obtained in step 4) is forged, tied into strips and then drawn into a wire with a diameter of 0.04 mm to obtain a finished product.

[0029] The wire material prepared in this embodiment is further used to make a thermocouple in pairs. The thermocouple has both high temperature measurement accuracy and good high temperature corrosion resistance.

[0030] The gradient structure platinum alloy material obtained by the present invention is composited with different kinds of platinum alloy materials, and a variety of composite functions are obtained by adjusting the composition, grain size, thickness and relative order of each layer of material. For example, in Example 1, a three-layer composite structure is designed, in which the upper and lower layers are composed of fine-grained dispersion-strengthened platinum materials, each accounting for 5% of the total thickness, and the middle layer is pure platinum material. The platinum crucible made of the plate obtained in this embodiment has significantly improved welding performance compared to the reinforced material. Therefore, through the above-mentioned design process, the composite material of the present invention has both processing performance similar to that of pure platinum material and surface corrosion resistance similar to that of dispersion-strengthened platinum material.

[0031] On the other hand, the dispersed phase on the surface of the dispersion-strengthened material has a strong resistance to fusion welding, and conventional diffusion composite, welding composite and other means cannot guarantee the interlayer bonding strength. The present invention adopts powder metallurgy hot isostatic pressing sintering technology to realize the composite of different layers of materials, and performs full-area pressure sintering between layers on a grain scale, which greatly reduces composite defects. At the same time, due to the spatial overlap of powder particles on both sides of the interface of different layers during the manufacturing process, the thickness of the interlayer welding area is further increased, thereby greatly improving the interlayer composite strength, ensuring that the material does not delaminate during processing, welding and use, and significantly improving the reliability of the material.

[0032] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the embodiments, ordinary technicians in the field should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should be included in the scope of protection requested by the claims of the present invention.

Claims

1. A gradient structure platinum alloy material, characterized in that: The platinum alloy material is composited by two to multiple layers of platinum alloy materials in different states, wherein the platinum alloy material is selected from one or more of dispersion-strengthened platinum material, pure platinum material, dispersion-strengthened platinum-rhodium alloy material, and pure platinum-rhodium alloy material.

2. The gradient structure platinum alloy material according to claim 1, characterized in that: Calculated by mass percentage, the rhodium content in the dispersion-strengthened platinum-rhodium alloy material is 0.1%wt to 30%wt, and the rhodium content in the pure platinum-rhodium alloy material is 0.1%wt to 30%wt.

3. The gradient structure platinum alloy material according to claim 1, characterized in that: The thickness of each layer of the platinum alloy material is ≥5 μm.

4. The gradient structure platinum alloy material according to claim 1, characterized in that: The grain size of each layer of the platinum alloy material is ≥0.5 μm.

5. A method for preparing a gradient structure platinum alloy material, characterized in that: The following steps are involved: Step 1) Powder batching: weigh several portions of platinum alloy powder in different states according to the material formula; Step 2) Filling the powder into the mold: According to the material formula, the platinum alloy powders in different states weighed in step 1) are layered and filled into a two-layer or multi-layer platinum mold, and different layers are separated by movable partitions; then the platinum mold filled with powder is placed on a vibration table, the vibration table is turned on to vibrate the powder and then the partition is removed; Step 3) hot isostatic pressing: the platinum mold processed in step 2) is sealed, and after vacuum pretreatment, the whole is placed in a hot isostatic pressing device for pressing to obtain a composite alloy blank; Step 4) diffusion treatment: after the blank obtained in step 3) is turned to remove the surface platinum mold, it is placed in a high-temperature furnace for thermal diffusion treatment to obtain a multi-layer alloy material; Step 5) calendering: the composite material obtained in step 4) is forged, rolled, rolled into strips, and drawn to obtain plates, rods, or wires.

6. The method for preparing a gradient structure platinum alloy material according to claim 5, characterized in that: The platinum alloy powders in different states in step 1) are selected from one or more of dispersion-strengthened platinum powder, pure platinum powder, dispersion-strengthened platinum-rhodium alloy powder, and pure platinum-rhodium alloy powder.

7. The method for preparing a gradient structure platinum alloy material according to claim 6, characterized in that: Calculated by mass percentage, the rhodium content in the dispersion-strengthened platinum-rhodium alloy powder is 0.1%wt to 30%wt, and the rhodium content in the pure platinum-rhodium alloy material is 0.1%wt to 30%wt.

8. The method for preparing a gradient structure platinum alloy material according to claim 5, characterized in that: The particle size range of the platinum alloy powder in different states in step 1) is 200nm≤D50≤200μm.

9. The method for preparing a gradient structure platinum alloy material according to claim 5, characterized in that: The thickness of each layer of the composite alloy material described in step 4) accounts for 5%-95% of the total thickness of the material.

10. The method for preparing a gradient structure platinum alloy material according to claim 5, characterized in that: The processing parameters of the hot isostatic pressing in step 3) are: a holding pressure of 100-200 MPa, a holding temperature of 1200-1700° C., and a holding time of 0.5-4 h; The parameters of the diffusion treatment in step 4) are: 400° C. for 2 h, 800° C. for 5 h, 1100° C. for 5 h, 1400° C. for 10 h, and then taken out and air-cooled.