Preparation method of negative expansion material Hf0. 87Ta0. 13Fe2Cux
The vacuum suspension smelting process addresses the issue of component uniformity in Hf 0.87 Ta 0.13 Fe2Cu x composite materials by ensuring full contact and uniform heating, resulting in improved mechanical properties for thermal expansion control.
Patent Information
- Application Number
- CN202411132883.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2024-12-06
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The preparation of Hf 0.87 Ta 0.13 Fe2Cu x composite materials using arc melting results in poor component uniformity due to insufficient stirring, affecting mechanical processing properties and hindering widespread application in microelectronic devices and precision optical instruments.
A vacuum suspension smelting process is employed, where copper, iron, and hafnium-tantalum particles are layered in a crucible according to melting points, with staged heating and cooling to ensure full contact and uniform heating, and electromagnetic stirring to improve component uniformity.
The method produces a negative expansion material with improved uniformity and mechanical properties, enhancing its suitability for applications requiring precise thermal expansion control.
Smart Images
Figure CN119082526A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of negative expansion materials, and in particular relates to a negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x Preparation method. Background Art
[0002] Due to the anharmonic vibration of atoms, most materials usually show the phenomenon of "thermal expansion and contraction". This positive thermal expansion causes the material size to change with the operating temperature. In the fields of microelectronic devices and precision optical instruments, the thermal stress generated by the thermal expansion of materials will seriously affect the normal function of the instrument, and in severe cases, it will cause the interface matching failure or fall off. 1-x Ta x Fe2 alloy exhibits abnormal thermal expansion near its magnetic transition temperature. This negative thermal expansion material has broad application prospects in the above-mentioned fields.
[0003] Hf 1-x Ta x Fe2 alloy is a pseudo-binary compound with strong brittleness. Room temperature brittleness and poor machinability are the main reasons for Hf 1-x Ta x The biggest obstacle to the use of Fe2 alloys. Therefore, it is necessary to find a metal material with better ductility and Hf 1- x Ta x Fe2 alloy composite can effectively improve the mechanical processing properties of materials and is of great significance for preparing low expansion or zero expansion materials.
[0004] Cu is a material with high thermal conductivity and excellent ductility. Research on the composite of negative expansion materials and Cu matrix has been carried out for a long time, such as ZrW2O8 / Cu, La(Fe,Si,Co) 13 / Cu and other composite materials. 0.87 Ta 0.13 Fe2Cu x The composite material has attracted widespread attention due to its near-zero expansion performance. The distribution of the second phase Cu phase in the Laves phase of the C14 structure improves the mechanical processing performance of the composite material. The content and distribution uniformity of the second phase Cu phase in the Laves phase of the C14 structure determine the excellent degree of mechanical processing performance of the material.
[0005] Currently, the preparation of Hf 0.87 Ta 0.13 Fe2Cu xThe commonly used method for alloying is arc melting, which uses electric energy to melt metal by forming an arc between the electrode and the material being melted; only when the arc is strong enough can it produce a slight stirring effect on the molten metal material in the copper crucible. If the arc strength is insufficient, it will not produce a stirring effect on the metal material in the copper crucible. It is impossible to maintain a high-intensity arc during arc melting, so Hf prepared by arc melting 0.87 Ta 0.13 Fe2Cu x The poor uniformity of composite material components affects the mechanical processing properties of the composite material and hinders its widespread application in actual production. Summary of the invention
[0006] In view of this, the object of the present invention is to provide a negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x A preparation method, which can prepare a negative expansion material Hf with good component uniformity 0.87 Ta 0.13 Fe2Cu x .
[0007] In order to achieve the above object, the present invention adopts the following technical solutions:
[0008] A negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x A preparation method, the preparation method comprising the following steps:
[0009] Step S1, preparing copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 3 to 15 mm according to a stoichiometric ratio (i.e., molar ratio) of 0.1 to 1:2:0.87:0.13; then laying the copper particles, iron particles, hafnium particles and tantalum particles layer by layer from bottom to top in a crucible fixedly installed in a suspension smelting furnace and having a groove at the bottom;
[0010] Step S2: Vacuum to 3-5×10 -3 Pa, then fill with argon to -0.08~-0.03KPa, within 10~15s, increase the heating power from 0 to 85~95kw, keep the heating power unchanged until the temperature in the suspension melting furnace reaches 1160~1230℃, then increase it to 110~120kw at a rate of 0.5~1.5kw / s, and perform vacuum suspension melting for 3~5min;
[0011] Step S3: Within 15 to 25 seconds, the heating power of 110 to 120 kW is reduced to 45 to 60 kW, and the temperature is kept for 8 to 12 seconds. Then, within 3 to 7 seconds, the heating power is reduced to 0 kW, and the negative expansion material Hf with a convex portion at the bottom is obtained by water cooling at a temperature of 380 to 620°C for 25 to 35 minutes. 0.87 Ta 0.13 Fe2Cu x .
[0012] Furthermore, after step S3, the preparation method further comprises the following steps:
[0013] Step S4: After wiping the crucible with alcohol for several times (2 to 4 times), the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x The convex part is placed in the crucible with the convex part facing upwards;
[0014] Step S5: Vacuum to 3-5×10 -3 Pa, then fill with argon to -0.08~-0.03KPa, increase the power from 0 to 130~140kw within 15~20s, keep the heating power unchanged, until the temperature in the suspension melting furnace reaches 1160~1230℃, then increase the heating power to 150~160kw at a rate of 0.5~1.5kw / s, and perform vacuum suspension melting for 3~5min;
[0015] Step S6: Within 30 to 40 seconds, the heating power of 150 to 160 kW is reduced to 90 to 120 kW, and the heat preservation is carried out for 15 to 20 seconds; within 45 to 55 seconds, the heating power of 90 to 120 kW is reduced to 45 to 60 kW, and the heat preservation is carried out for 10 to 15 seconds, and then within 10 to 15 seconds, the heating power is reduced to 0 kW, and the negative expansion material Hf is obtained by water cooling at a temperature of 380 to 620°C for 25 to 35 minutes. 0.87 Ta 0.13 Fe2Cu x .
[0016] Furthermore, in the step S1, the purity of the copper particles, iron particles, hafnium particles and tantalum particles is 99.5-99.8%.
[0017] Furthermore, in step S2, the vacuum degree after evacuation is 3.5 to 4.5×10 -3 Pa, and then fill with argon to -0.06~-0.04KPa.
[0018] Furthermore, in step S3, the negative expansion material Hf 0.87 Ta 0.13 Fe2Cux The expansion coefficient at a temperature of -100°C to 25°C is -0.20 to -0.15 ppm / °C.
[0019] Furthermore, in step S6, the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x The expansion coefficient at a temperature of -100°C to 25°C is -0.44 to -0.36 ppm / °C.
[0020] In summary, the technical solution of the present invention has the following technical effects:
[0021] The present invention sequentially places copper particles, iron particles, hafnium particles and tantalum particles into a crucible of a suspension smelting furnace in the order of melting points from low to high, from the bottom to the top of the crucible, so as to ensure that during vacuum suspension smelting, copper and iron with low melting points melt first at the bottom of the crucible, provide a molten liquid environment, and promote hafnium and tantalum with high melting points in the upper half of the crucible to continue to melt. Meanwhile, the copper and iron with low melting points are prevented from splashing out of the crucible during vacuum suspension smelting to damage the coil inside the smelting furnace (if copper with low melting points is added to the crucible last, the copper liquid melted first during the smelting process is easy to splash outside the crucible); the heating power is adjusted in stages (i.e., the temperature is increased in stages) so that the molten metal materials are Full contact and uniform heating improve the uniformity of the negative expansion material ingot; by slowly reducing the power in stages (i.e., staged cooling), the metal column in a suspended state slowly falls down, avoiding the formation of large shrinkage holes in the negative expansion material ingot due to too fast cooling speed, resulting in a large number of defects; vacuum suspension smelting is adopted, and during the smelting process, the metal material melt is in the magnetic field, and the vertical electromagnetic force and gravity offset each other, so that the melt is in a suspended state, and the electromagnetic force in other directions will produce a continuous electromagnetic stirring effect on the melt, so that the Hf, Ta, Fe, and Cu metal materials are fully in contact in the molten state, without crucible pollution, and the alloy is pure, ensuring the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x The uniformity of the components improves the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu x thermodynamic properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 The negative expansion material Hf of Example 1 0.87 Ta 0.13 Fe2Cu 0.1 Metallographic diagram;
[0024] Figure 2 The negative expansion material Hf of Example 2 0.87 Ta 0.13 Fe2Cu 0.5 Metallographic diagram;
[0025] Figure 3 The negative expansion material Hf of Example 3 0.87 Ta 0.13 Metallographic diagram of Fe2Cu1. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0027] Embodiment 1:
[0028] Step S1, prepare copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 3 mm and a purity of 99.5% according to the stoichiometric ratio of 0.1:2:0.87:0.13; then lay the copper particles, iron particles, hafnium particles and tantalum particles in a crucible with a groove at the bottom fixedly installed in the suspension smelting furnace in layers from bottom to top in the order of copper particles, iron particles, hafnium particles and tantalum particles. The suspension smelting furnace is a 10kg smelting furnace, and the crucible size is φ50mm*100mm.
[0029] Step S2: Vacuum to 3×10 -3 Pa, and then fill with argon to -0.08KPa. Within 10s, increase the heating power from 0 to 85kw, and keep the heating power of 85kw unchanged until the temperature in the suspension melting furnace reaches 1160℃, and then increase it to 110kw at a rate of 0.5kw / s, and carry out vacuum suspension melting for 3min.
[0030] Step S3: Within 15 seconds, the heating power of 110 kW is reduced to 45 kW, and the temperature is kept for 8 seconds. Then, within 3 seconds, the heating power is reduced to 0 kW, and the product is water-cooled at 380°C for 25 minutes to obtain a negative expansion material Hf having a convex portion at the bottom and an expansion coefficient of -0.15 ppm / °C at a temperature of -100°C-25°C.0.87 Ta 0.13 Fe2Cu 0.1 .
[0031] Step S4: After wiping the crucible twice with alcohol, add the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu 0.1 Place it in the crucible with the raised part facing upward.
[0032] Step S5: Vacuum to 3×10 -3 Pa, and then fill with argon to -0.08KPa, increase the power from 0 to 130kw within 15s, and maintain the heating power of 130kw unchanged until the temperature in the suspension melting furnace reaches 1160℃, then increase the heating power to 150kw at a rate of 0.5kw / s per second, and carry out vacuum suspension melting for 3min.
[0033] Step S6: Within 30 seconds, the heating power of 150 kW is reduced to 90 kW, and the heat preservation is carried out for 15 seconds; within 45 seconds, the heating power of 90 kW is reduced to 45 kW, and the heat preservation is carried out for 10 seconds, and then within 10 seconds, the heating power is reduced to 0 kW, and the water-cooled molding is carried out at a temperature of 380°C for 25 minutes to obtain a negative expansion material Hf having an expansion coefficient of -0.44 ppm / °C at a temperature of -100°C-25°C 0.87 Ta 0.13 Fe2Cu 0.1 .
[0034] From negative expansion material Hf 0.87 Ta 0.13 Fe2Cu 0.1 The metallographic diagram shows that the negative expansion material Hf 0.87 Ta 0.13 The second phase Cu of Fe2Cu1 is evenly distributed in the Laves phase of C14 structure.
[0035] Embodiment 2:
[0036] Step S1, prepare copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 15 mm and a purity of 99.8% according to the stoichiometric ratio of 1:2:0.87:0.13; then lay the copper particles, iron particles, hafnium particles and tantalum particles layer by layer from bottom to top in a crucible fixedly installed in a suspension smelting furnace with a groove at the bottom. The suspension smelting furnace is a 10kg smelting furnace, and the crucible size is φ50mm*100mm.
[0037] Step S2: Vacuum to 5×10 -3Pa, and then fill with argon to -0.03KPa. Within 15s, increase the heating power from 0 to 95kw, and maintain the 95kw heating power unchanged until the temperature in the suspension melting furnace reaches 1230℃, and then increase it to 120kw at a rate of 1.5kw / s, and carry out vacuum suspension melting for 5min.
[0038] Step S3: Within 25 seconds, the heating power of 120 kW is reduced to 60 kW, and the temperature is kept for 12 seconds. Then, within 7 seconds, the heating power is reduced to 0 kW, and the product is water-cooled at 620°C for 35 minutes to obtain a negative expansion material Hf having a convex portion at the bottom and an expansion coefficient of -0.20 ppm / °C at a temperature of -100°C-25°C. 0.87 Ta 0.13 Fe2Cu1.
[0039] Step S4: After wiping the crucible with alcohol 4 times, add the negative expansion material Hf 0.87 Ta 0.13 The raised portion of Fe2Cu1 is placed in the crucible with the raised portion facing upward.
[0040] Step S5: Vacuum to 5×10 -3 Pa, and then fill with argon to -0.03KPa, increase the power from 0 to 140kw within 20s, and maintain the heating power of 140kw unchanged until the temperature in the suspension melting furnace reaches 1230℃, then increase the heating power to 160kw at a rate of 1.5kw / s per second, and carry out vacuum suspension melting for 5min.
[0041] Step S6: Within 40 seconds, the heating power of 160 kW is reduced to 120 kW, and the temperature is kept for 20 seconds; within 55 seconds, the heating power of 120 kW is reduced to 60 kW, and the temperature is kept for 15 seconds, and then within 15 seconds, the heating power is reduced to 0 kW, and the water-cooled molding is performed at a temperature of 620°C for 35 minutes to obtain a negative expansion material Hf having an expansion coefficient of -0.44 ppm / °C at a temperature of -100°C-25°C. 0.87 Ta 0.13 Fe2Cu1.
[0042] From negative expansion material Hf 0.87 Ta 0.13 The metallographic diagram of Fe2Cu1 shows that the negative expansion material Hf 0.87 Ta 0.13 The second phase Cu of Fe2Cu1 is evenly distributed in the Laves phase of C14 structure.
[0043] Embodiment 3:
[0044] Step S1, prepare copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 8 mm and a purity of 99.7% according to the stoichiometric ratio of 0.5:2:0.87:0.13; then lay the copper particles, iron particles, hafnium particles and tantalum particles layer by layer from bottom to top in a crucible fixedly installed in a suspension smelting furnace with a groove at the bottom. The suspension smelting furnace is a 10kg smelting furnace, and the crucible size is φ50mm*100mm.
[0045] Step S2: Vacuum to 4.5×10 -3 Pa, and then fill with argon to -0.04KPa. Within 12s, increase the heating power from 0 to 90kw, and keep the 90kw heating power unchanged until the temperature in the suspension melting furnace reaches 1200℃, and then increase it to 115kw at a rate of 1kw / s, and carry out vacuum suspension melting for 4min.
[0046] Step S3: Within 20 seconds, the heating power of 115 kW is reduced to 50 kW, and the temperature is kept for 10 seconds. Then, within 5 seconds, the heating power is reduced to 0 kW, and the mold is water-cooled at 500°C for 30 minutes to obtain a negative expansion material Hf having a convex portion at the bottom and an expansion coefficient of -0.18 ppm / °C at a temperature of -100°C-25°C. 0.87 Ta 0.13 Fe2Cu 0.5 .
[0047] Step S4: After wiping the crucible with alcohol for 3 times, add the negative expansion material Hf 0.87 Ta 0.13 Fe2Cu 0.5 Place it in the crucible with the raised part facing upward.
[0048] Step S5: Vacuum to 4.5×10 -3 Pa, and then fill with argon to -0.04KPa, increase the power from 0 to 135kw within 18s, and maintain the heating power of 135kw unchanged until the temperature in the suspension melting furnace reaches 1200℃, then increase the heating power to 155kw at a rate of 1kw / s per second, and carry out vacuum suspension melting for 4min.
[0049] Step S6: Within 35 seconds, the heating power of 155kw is reduced to 100kw, and the temperature is kept for 18 seconds; within 50 seconds, the heating power of 100kw is reduced to 50kw, and the temperature is kept for 12 seconds, and then within 12 seconds, the heating power is reduced to 0kw, and the water-cooled molding is carried out at a temperature of 500°C for 30 minutes to obtain a negative expansion material Hf with an expansion coefficient of -0.40ppm / °C at a temperature of -100°C-25°C 0.87 Ta 0.13 Fe2Cu 0.5.
[0050] From negative expansion material Hf 0.87 Ta 0.13 Fe2Cu 0.5 The metallographic diagram shows that the negative expansion material Hf 0.87 Ta 0.13 The second phase Cu of Fe2Cu1 is evenly distributed in the Laves phase of C14 structure.
[0051] Embodiment 4:
[0052] Step S1, prepare copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 10 mm and a purity of 99.6% according to the stoichiometric ratio of 0.5:2:0.87:0.13; then lay the copper particles, iron particles, hafnium particles and tantalum particles in a crucible with a groove at the bottom fixedly installed in the suspension smelting furnace in layers from bottom to top in the order of copper particles, iron particles, hafnium particles and tantalum particles. The suspension smelting furnace is a 10kg smelting furnace, and the crucible size is φ50mm*100mm.
[0053] Step S2: Vacuum to 3.5×10 -3 Pa, and then fill with argon to -0.06KPa. Within 14s, increase the heating power from 0 to 88kw, and keep the heating power of 88kw unchanged until the temperature in the suspension melting furnace reaches (1180℃, then increase it to 118kw at a rate of 1.2kw / s, and perform vacuum suspension melting for 4min.
[0054] Step S3: Within 22 seconds, the heating power of 118 kW is reduced to 55 kW, and the temperature is kept for 10 seconds. Then, within 5 seconds, the heating power is reduced to 0 kW, and the product is water-cooled at 550°C for 28 minutes to obtain a negative expansion material Hf having a convex portion at the bottom and an expansion coefficient of -0.16 ppm / °C at a temperature of -100°C-25°C. 0.87 Ta 0.13 Fe2Cu 0.5 .
[0055] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.
Claims
1. A negative expansion material Hf 0.87 Ta 0.13 Fe 2 Cu x The preparation method of It is characterized in that The preparation method comprises the following steps: Step S1, preparing copper particles, iron particles, hafnium particles and tantalum particles with a diameter of 3 to 15 mm according to a stoichiometric ratio of 0.1 to 1:2:0.87:0.13; then laying the copper particles, iron particles, hafnium particles and tantalum particles layer by layer from bottom to top in a crucible fixedly installed in a suspension smelting furnace and having a groove at the bottom; Step S2: Vacuum to 3-5×10 -3 Pa, then fill with argon to -0.08~-0.03KPa, within 10~15s, increase the heating power from 0 to 85~95kw, keep the heating power unchanged until the temperature in the suspension melting furnace reaches 1160~1230℃, then increase it to 110~120kw at a rate of 0.5~1.5kw / s, and perform vacuum suspension melting for 3~5min; Step S3: Within 15 to 25 seconds, the heating power of 110 to 120 kW is reduced to 45 to 60 kW, and the temperature is kept for 8 to 12 seconds. Then, within 3 to 7 seconds, the heating power is reduced to 0 kW, and the negative expansion material Hf with a convex portion at the bottom is obtained by water cooling at a temperature of 380 to 620°C for 25 to 35 minutes. 0.87 Ta 0.13 Fe 2 Cu x .
2. The preparation method according to claim 1, It is characterized in that After step S3, the preparation method further comprises the following steps: Step S4: After wiping the crucible with alcohol for several times, the negative expansion material Hf 0.87 Ta 0.13 Fe 2 Cu x The convex part is placed in the crucible with the convex part facing upwards; Step S5: Vacuum to 3-5×10 -3 Pa, then fill with argon to -0.08~-0.03KPa, increase the power from 0 to 130~140kw within 15~20s, keep the heating power unchanged, until the temperature in the suspension melting furnace reaches 1160~1230℃, then increase the heating power to 150~160kw at a rate of 0.5~1.5kw / s, and perform vacuum suspension melting for 3~5min; Step S6: Within 30 to 40 seconds, the heating power of 150 to 160 kW is reduced to 90 to 120 kW, and the heat preservation is carried out for 15 to 20 seconds; within 45 to 55 seconds, the heating power of 90 to 120 kW is reduced to 45 to 60 kW, and the heat preservation is carried out for 10 to 15 seconds, and then within 10 to 15 seconds, the heating power is reduced to 0 kW, and the negative expansion material Hf is obtained by water cooling at a temperature of 380 to 620°C for 25 to 35 minutes. 0.87 Ta 0.13 Fe 2 Cu x .
3. The preparation method according to claim 2, It is characterized in that In the step S1, the purity of the copper particles, iron particles, hafnium particles and tantalum particles is 99.5-99.8%.
4. The preparation method according to claim 3, It is characterized in that In step S2, the vacuum degree after evacuation is 3.5-4.5×10 -3 Pa, and then fill with argon to -0.06~-0.04KPa.
5. The preparation method according to claim 4, It is characterized in that In step S3, the negative expansion material Hf 0.87 Ta 0.13 Fe 2 Cu x The expansion coefficient at a temperature of -100°C to 25°C is -0.20 to -0.15 ppm / °C.
6. The preparation method according to claim 5, It is characterized in that In step S6, the negative expansion material Hf 0.87 Ta 0.13 Fe 2 Cu x The expansion coefficient at a temperature of -100°C to 25°C is -0.44 to -0.36 ppm / °C.