阅读说明：本技术 一种利用梯度铜钨合金粉末制备铜钨梯度功能材料的工艺 (Process for preparing copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder ) 是由 刘萍 周兴 康迪 王小军 周宁 于 2020-10-19 设计创作，主要内容包括：本发明提供了一种利用梯度铜钨合金粉末制备铜钨梯度功能材料的工艺,具体包括：混粉基体的制备：混合带有不同比例成型剂的各个梯度铜钨粉末,得到含有不同比例成型剂的各个梯度铜钨粉末的混粉基体；压制：将混好的不同比例成型剂的各个梯度铜钨粉末的混粉基体根据需求分别倒入适合的模具中,在液压机上进行压制,得到各个成型工件；脱胶：进行烧结脱胶；烧结：将准备好的铜块放在不同梯度的铜钨坯块上,再在钼丝炉进行液相烧结；采用本发明方法进行铜钨梯度材料的制备,能够有效地降低材料成本及设备要求,进一步降低成本,提高材料性能,并且满足批量化生产。(The invention provides a process for preparing a copper-tungsten gradient functional material by using gradient copper-tungsten alloy powder, which specifically comprises the following steps: preparing a mixed powder matrix: mixing the gradient copper-tungsten powder with the forming agents in different proportions to obtain a mixed powder matrix containing the gradient copper-tungsten powder with the forming agents in different proportions; pressing: respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to requirements, and pressing on a hydraulic press to obtain each formed workpiece; degumming: sintering and degumming; and (3) sintering: placing the prepared copper blocks on copper-tungsten briquettes with different gradients, and then performing liquid phase sintering in a molybdenum wire furnace; the method for preparing the copper-tungsten gradient material can effectively reduce the material cost and the equipment requirement, further reduce the cost, improve the material performance and meet the requirement of batch production.)

1. A process for preparing a copper-tungsten gradient functional material by using gradient copper-tungsten alloy powder is characterized by specifically comprising the following steps of:

the method comprises the following steps: preparation of the Mixed powder matrix

Mixing the gradient copper-tungsten powder with the forming agents in different proportions to obtain a mixed powder matrix containing the gradient copper-tungsten powder with the forming agents in different proportions;

step two: pressing

Respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to requirements, and pressing on a hydraulic press to obtain each formed workpiece;

step three: degumming

Charging the formed workpieces into a furnace, vacuumizing and maintaining the vacuum at 90-110 Pa; heating to 120 ℃ at a speed of 4-6 ℃/min, preserving heat for 30min, heating to 500 ℃ at a speed of 2-4 ℃/min, preserving heat for 60min, heating to 700 ℃ at a speed of 1-2 ℃/min, preserving heat for 60min, heating to 900 ℃ at a speed of 2-4 ℃/min, preserving heat for 120min, then closing heating and cooling, discharging at a temperature of less than 100 ℃ to obtain copper-tungsten billets with different gradients;

step four: sintering

And placing the prepared copper blocks on copper-tungsten briquettes with different gradients, and then performing liquid phase sintering in a molybdenum wire furnace.

2. The process for preparing the copper-tungsten gradient functional material by using the gradient copper-tungsten alloy powder as claimed in claim 1, wherein the step one comprises the following specific steps: and respectively putting the copper and tungsten powder with different gradients into a mixing machine in batches, then respectively putting the forming agents with different proportions into the mixing machine, and mixing for 4-6 h to obtain a mixed powder matrix of the copper and tungsten powder with different gradients, wherein the forming agents account for 0.5-4.5% of the copper and tungsten powder by mass percent.

3. The process for preparing copper-tungsten gradient functional material by using the gradient copper-tungsten alloy powder as claimed in claim 2, wherein the ratio of the forming agent added in each gradient copper-tungsten powder is different, wherein the ratio of the forming agent added in CuW55 is 4.5%, the ratio of the forming agent added in CuW60 is 4%, the ratio of the forming agent added in CuW65 is 3.5%, the ratio of the forming agent added in CuW70 is 3%, the ratio of the forming agent added in CuW75 is 2.5%, the ratio of the forming agent added in CuW80 is 1.5%, the ratio of the forming agent added in CuW85 is 1%, and the ratio of the forming agent added in CuW90 is 0.5.

4. The process for preparing copper-tungsten gradient functional material by using gradient copper-tungsten alloy powder according to claim 1, wherein the forming agent is SBP glue.

5. The process for preparing the copper-tungsten gradient functional material by using the gradient copper-tungsten alloy powder as claimed in claim 1, wherein the specific steps of the second step are as follows: and respectively pouring the mixed powder matrix of the gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to the requirement, and adjusting the pressure to 60T on a 200T hydraulic press for pressing to obtain a formed workpiece.

6. The process for preparing the copper-tungsten gradient functional material by using the gradient copper-tungsten alloy powder as claimed in claim 1, wherein the specific process of the fourth step is as follows: and putting the prepared copper blocks on copper-tungsten briquettes with different gradients, putting the copper blocks into a molybdenum wire furnace, carrying out infiltration at 1200-1450 ℃, and carrying out liquid phase sintering under the condition of 2 h/boat to ensure that copper is fully infiltrated into the briquettes.

7. The process for preparing the copper-tungsten gradient functional material by using the gradient copper-tungsten alloy powder as claimed in claim 1, wherein the sintering temperature of the fourth step is 1200-1450 ℃.

8. The application of the copper-tungsten gradient functional material prepared by the method according to any one of claims 1 to 7, wherein the copper-tungsten gradient functional material is selected to be correspondingly graded according to actual product requirements to manufacture various types of heat sink materials, liner materials, electronic packaging materials and electrical contact materials.

9. The use of claim 8, wherein two copper-tungsten graded functional materials, CuW60 and CuW80, are selected, the base layer made of CuW60 and the working surface layer made of CuW80 are used to manufacture the high-voltage switch component for opening and closing the circuit.

Technical Field

The invention relates to the technical field of preparation of copper-tungsten gradient functional materials, in particular to a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder.

Background

The tungsten copper material is a so-called pseudo alloy because it is composed of tungsten having a high melting point and high hardness and copper having a high electrical conductivity and high thermal conductivity, and the tungsten and copper are not solid-dissolved with each other.

The tungsten-copper composite material is a two-phase pseudo alloy consisting of two metals of tungsten and copper with large difference in physical and chemical properties, and each property of the tungsten-copper composite material can change along with the change of the structure.

The tungsten-copper material has the advantages that the intrinsic physical properties of tungsten and copper are presented in terms of performance, and the tungsten-copper material has the characteristics of high strength, high hardness and low expansion of tungsten and also has the high electric conductivity and high heat conductivity of copper; therefore, the material is widely applied to the industries of aerospace, aviation, electronics, electric power, metallurgy, machinery, civil equipment and the like.

In the prior art, copper-tungsten alloy is prepared by a powder metallurgy method, powder containing copper and tungsten in different proportions is subjected to hot pressing, multiple processes such as hot pressing, degreasing, hydrogen sintering and the like are involved, certain requirements are imposed on pressing equipment and sintering equipment, the copper-tungsten alloy is not suitable for batch production, and the material cost and the processing cost in the production process are high.

Disclosure of Invention

Aiming at the existing problems, the invention provides a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder, and the method can reduce the material cost and equipment requirements, further reduce the cost, improve the material performance and meet the requirement of batch production.

The technical scheme of the invention is as follows: a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder specifically comprises the following steps:

the method comprises the following steps: preparation of the Mixed powder matrix

Mixing the gradient copper-tungsten powder with the forming agents in different proportions to obtain a mixed powder matrix containing the forming agents in different proportions;

step two: pressing

Respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to requirements, and pressing on a hydraulic press to obtain each formed workpiece;

step three: degumming

Charging the formed workpieces into a furnace, vacuumizing and maintaining the vacuum at 90-110 Pa; heating to 120 ℃ at a speed of 4-6 ℃/min, preserving heat for 30min, heating to 500 ℃ at a speed of 2-4 ℃/min, preserving heat for 60min, heating to 700 ℃ at a speed of 1-2 ℃/min, preserving heat for 60min, heating to 900 ℃ at a speed of 2-4 ℃/min, preserving heat for 120min, then turning off the furnace to cool, discharging at a temperature of less than 100 ℃ to obtain copper-tungsten billets with different gradients; the density of the formed workpiece can be slowly increased by adopting a gradient heating treatment mode, so that the particles can be tightly contacted until a tightly packed structure is formed, and the degumming treatment is more thorough;

step four: sintering

And placing the prepared copper blocks on copper-tungsten briquettes with different gradients, and then performing liquid phase sintering in a molybdenum wire furnace.

Further, the step one comprises the following specific steps: and respectively putting the copper and tungsten powder with different gradients into a mixing machine in batches, then respectively putting the forming agents with different proportions into the mixing machine, and mixing for 4-6 h to obtain a mixed powder matrix of the copper and tungsten powder with different gradients, wherein the forming agents account for 0.5-4.5% of the copper and tungsten powder by mass percent.

Furthermore, the proportion of the forming agent added in each gradient copper-tungsten powder is different, wherein the proportion of the forming agent added in CuW55 is 4.5%, the proportion of the forming agent added in CuW60 is 4%, the proportion of the forming agent added in CuW65 is 3.5%, the proportion of the forming agent added in CuW70 is 3%, the proportion of the forming agent added in CuW75 is 2.5%, the proportion of the forming agent added in CuW80 is 1.5%, the proportion of the forming agent added in CuW85 is 1%, and the proportion of the forming agent added in CuW90 is 0.5%; the forming agents with different contents are added into the copper-tungsten powder with different gradients, so that the raw materials can be effectively saved and the cost can be reduced on the basis of forming.

Furthermore, the forming agent specifically adopts SBP glue; SBP glue has strong caking property, and can ensure that the green compact strength of a formed workpiece is higher.

Further, the specific steps of the second step are as follows: and respectively pouring the mixed powder matrix of the gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to the requirement, and adjusting the pressure to 60T on a 200T hydraulic press for pressing to obtain a formed workpiece.

Further, the fourth specific process is as follows: putting the prepared copper blocks on copper-tungsten briquettes with different gradients, putting the copper blocks into a molybdenum wire furnace, carrying out infiltration at 1200-1450 ℃, and carrying out liquid phase sintering under the condition of 2 h/boat to ensure that copper is fully infiltrated into the briquettes; the liquid phase sintering mode can rearrange the particles of the degummed formed workpiece, and is more beneficial to fully infiltrating copper into the compact.

Further, the copper-tungsten gradient functional material is selected to be correspondingly graded according to actual product requirements to manufacture various types of heat sink materials, shaped charge liner materials, electronic packaging materials and electrical contact materials.

Furthermore, two copper-tungsten gradient functional materials of CuW60 and CuW80 are selected, a base layer made of CuW60 and a working surface layer made of CuW80 are selected, and the high-voltage switch component for the circuit breaking is manufactured.

Further, the fourth specific process is as follows: placing the prepared copper block on copper-tungsten billets with different gradients, placing the copper block into a microwave oven, and then carrying out infiltration at 1200-1450 ℃ under a 2.45GHz microwave auxiliary thermal field to ensure that copper is fully infiltrated into the billets; the microwave-assisted sintering is beneficial to reducing the sintering time, and can accelerate the densification process, so that the structure of the alloy is more uniform.

Compared with the prior art, the invention has the beneficial effects that: the method for preparing the copper-tungsten gradient material can effectively reduce the material cost and the equipment requirement, further reduce the cost, improve the material performance and meet the requirement of batch production; and has the following characteristics: 1) no special requirement on the granularity of the raw material powder; 2) the multilayer gradient material is directly formed in one step under a conventional hydraulic press without hot pressing; 3) sintering and copper infiltration are carried out in a continuous sintering furnace, so that the production efficiency is improved; 4) the thickness of each layer of the gradient material is easy to control.

Detailed Description

Example 1: a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder specifically comprises the following steps:

the method comprises the following steps: preparation of the Mixed powder matrix

Different gradients of copper tungsten powder: respectively putting CuW55 powder, CuW60 powder, CuW65 powder, CuW70 powder, CuW75 powder, CuW80 powder, CuW85 powder and CuW90 powder into a mixer in batches, respectively putting a forming agent accounting for 0.5 percent of the mass of each copper-tungsten powder into the mixer, and mixing for 4 hours to obtain a mixed powder matrix of each gradient copper-tungsten powder: 0.5% of forming agent-containing CuW55 powder, 0.5% of forming agent-containing CuW60 powder, 0.5% of forming agent-containing CuW65 powder, 0.5% of forming agent-containing CuW70 powder, 0.5% of forming agent-containing CuW75 powder, 0.5% of forming agent-containing CuW80 powder, 0.5% of forming agent-containing CuW85 powder, and 0.5% of forming agent-containing CuW90 powder; wherein the forming agent specifically adopts SBP glue;

step two: pressing

Respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to the requirement, and adjusting the pressure to 60T on a 200T hydraulic press for pressing to obtain each formed workpiece;

step three: degumming

Charging the formed workpieces into a furnace, vacuumizing and maintaining the vacuum at 90 Pa; heating to 120 ℃ at a speed of 4 ℃/min, preserving heat for 30min, heating to 500 ℃ at a speed of 2 ℃/min, preserving heat for 60min, heating to 700 ℃ at a speed of 1 ℃/min, preserving heat for 60min, heating to 900 ℃ at a speed of 2 ℃/min, preserving heat for 120min, then closing the heating and cooling, discharging at 60 ℃ and obtaining copper-tungsten billets with different gradients;

step four: sintering

And putting the prepared copper blocks on copper-tungsten briquettes with different gradients, putting the copper blocks into a molybdenum wire furnace, and carrying out infiltration at 1200 ℃ and liquid-phase sintering under the condition of 2 h/boat to ensure that copper is fully infiltrated into the briquettes.

The copper-tungsten gradient functional material with corresponding gradient is selected according to the actual product requirements to manufacture various types of heat sink materials, shaped charge liner materials, electronic packaging materials and electrical contact materials.

Example 2: a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder specifically comprises the following steps:

the method comprises the following steps: preparation of the Mixed powder matrix

Different gradients of copper tungsten powder: respectively putting CuW55 powder, CuW60 powder, CuW65 powder, CuW70 powder, CuW75 powder, CuW80 powder, CuW85 powder and CuW90 powder into a mixer in batches, respectively putting a forming agent accounting for 2 percent of the mass of each copper-tungsten powder into the mixer, and mixing for 5 hours to obtain a mixed powder matrix of each gradient copper-tungsten powder: 2% forming agent CuW55 powder, 2% forming agent CuW60 powder, 2% forming agent CuW65 powder, 2% forming agent CuW70 powder, 2% forming agent CuW75 powder, 2% forming agent CuW80 powder, 2% forming agent CuW85 powder, 2% forming agent CuW90 powder; wherein the forming agent specifically adopts SBP glue;

step two: pressing

Respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to the requirement, and adjusting the pressure to 60T on a 200T hydraulic press for pressing to obtain each formed workpiece;

step three: degumming

Charging the formed workpieces into a furnace, vacuumizing and maintaining the vacuum at 100 Pa; heating to 120 ℃ at a speed of 5 ℃/min, preserving heat for 30min, heating to 500 ℃ at a speed of 3 ℃/min, preserving heat for 60min, heating to 700 ℃ at a speed of 2 ℃/min, preserving heat for 60min, heating to 900 ℃ at a speed of 3 ℃/min, preserving heat for 120min, then closing the heating and cooling, discharging at 50 ℃ to obtain copper-tungsten billets with different gradients;

step four: sintering

And putting the prepared copper blocks on copper-tungsten briquettes with different gradients, putting the copper blocks into a molybdenum wire furnace, and carrying out infiltration at 1300 ℃ and liquid-phase sintering under the condition of 2 h/boat to ensure that copper is fully infiltrated into the briquettes.

The copper-tungsten gradient functional material with corresponding gradient is selected according to the actual product requirements to manufacture various types of heat sink materials, shaped charge liner materials, electronic packaging materials and electrical contact materials.

Example 3: a process for preparing a copper-tungsten gradient functional material by utilizing gradient copper-tungsten alloy powder specifically comprises the following steps:

the method comprises the following steps: preparation of the Mixed powder matrix

Different gradients of copper tungsten powder: respectively putting CuW55 powder, CuW60 powder, CuW65 powder, CuW70 powder, CuW75 powder, CuW80 powder, CuW85 powder and CuW90 powder into a mixer in batches, respectively putting 4 mass percent of forming agent of each copper-tungsten powder into the mixer, and mixing for 6 hours to obtain a mixed powder matrix of each gradient copper-tungsten powder: CuW55 powder containing 4% of forming agent, CuW60 powder containing 4% of forming agent, CuW65 powder containing 4% of forming agent, CuW70 powder containing 4% of forming agent, CuW75 powder containing 4% of forming agent, CuW80 powder containing 4% of forming agent, CuW85 powder containing 4% of forming agent and CuW90 powder containing 4% of forming agent; wherein the forming agent specifically adopts SBP glue;

step two: pressing

Respectively pouring the mixed powder matrix of each gradient copper-tungsten powder of the mixed forming agents with different proportions into a proper mould according to the requirement, and adjusting the pressure to 60T on a 200T hydraulic press for pressing to obtain each formed workpiece;

step three: degumming

Charging the formed workpieces into a furnace, vacuumizing and maintaining the vacuum at 110 Pa; heating to 120 ℃ at a speed of 6 ℃/min, preserving heat for 30min, heating to 500 ℃ at a speed of 4 ℃/min, preserving heat for 60min, heating to 700 ℃ at a speed of 2 ℃/min, preserving heat for 60min, heating to 900 ℃ at a speed of 4 ℃/min, preserving heat for 120min, then closing the heating and cooling, discharging at 20 ℃ and obtaining copper-tungsten billets with different gradients;

step four: sintering

And putting the prepared copper blocks on copper-tungsten briquettes with different gradients, putting the copper blocks into a molybdenum wire furnace, carrying out infiltration at 1450 ℃, and carrying out liquid phase sintering under the condition of 2 h/boat to ensure that the copper is fully infiltrated into the briquettes.

The copper-tungsten gradient functional material with corresponding gradient is selected according to the actual product requirements to manufacture various types of heat sink materials, shaped charge liner materials, electronic packaging materials and electrical contact materials.

Example 4: the difference from example 1 is: the proportion of the forming agent added in each gradient copper-tungsten powder is different, wherein the proportion of the forming agent added in CuW55 is 4.5%, the proportion of the forming agent added in CuW60 is 4%, the proportion of the forming agent added in CuW65 is 3.5%, the proportion of the forming agent added in CuW70 is 3%, the proportion of the forming agent added in CuW75 is 2.5%, the proportion of the forming agent added in CuW80 is 1.5%, the proportion of the forming agent added in CuW85 is 1%, and the proportion of the forming agent added in CuW90 is 0..

Example 5: the difference from example 1 is: the fourth specific process comprises the following steps: putting the prepared copper block on copper-tungsten billets with different gradients, putting the copper block into a microwave oven, and then carrying out infiltration at 1300 ℃ under a 2.45GHz microwave-assisted thermal field to ensure that copper is fully infiltrated into the billets; the microwave-assisted sintering is beneficial to reducing the sintering time, and can accelerate the densification process, so that the structure of the alloy is more uniform.

Application example: preparing a high-voltage switch part for switching on and off a circuit by using the methods of the embodiments 1 to 5 respectively, wherein the high-voltage switch part comprises a base layer made of CuW60 and a working surface layer made of CuW80 and arranged on the base layer; the base layer is better connected with an external base material made of CuCr1 by taking CuW60 as a material; the working surface layer is made of CuW80, because the performance of CuW80 is better than that of CuW60, and the voltage grade of the working surface layer is higher.

Respectively carrying out performance parameter test on the prepared high-voltage switch parts, wherein the test structure is as follows:

and (4) conclusion: the high-voltage switch parts prepared by the method can meet the product performance, and the interface between the basic layer and the working surface layer is firmly combined.