A kind of melt-infiltrated tungsten-copper composite material and its manufacturing method

Abstract

The present invention proposes a melt-infiltrated tungsten-copper composite material and a manufacturing method thereof. The method comprises: step 1: batching and ball milling: batching by weight percentage Ni: 0.7% to 1.0%, Cu: 2.4% to 2.6%, and the balance W, and putting in a hard alloy ball for mixing; step 2: adding paraffin wax to the mixed powder, the addition amount is 2.5%; step 3: pressing into a tungsten-copper column blank with a hydraulic press under a pressure of 40T; step 4: pressing the pure copper powder into a column blank with a hydraulic press under a pressure of 40T; step 5: dewaxing the pressed tungsten-copper column blank in a push rod dewaxing furnace; step 6: pre-sintering the pressed tungsten-copper column blank in a continuous hydrogen sintering furnace; step 7: stacking the sintered column blank and the pure copper column blank in a molybdenum boat and infiltrating copper sintering in a continuous hydrogen sintering furnace; step 8: machining the copper-infiltrated column blank into a product that meets the requirements. The tungsten-copper composite material manufactured by the melt infiltration method has good physical and mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of material manufacturing, and in particular relates to a melt-infiltrated tungsten-copper composite material and a manufacturing method thereof. Background Art

[0002] Tungsten copper composite material is a composite material composed of tungsten particles with a body-centered cubic structure and copper bonding phase with a face-centered cubic structure. This composite material has the characteristics of tungsten such as high strength, high hardness, and low expansion coefficient, and has the characteristics of copper such as high plasticity and good electrical and thermal conductivity. Therefore, it has been widely used. Specifically, it can be used to prepare important materials such as resistance welding and electrical contacts.

[0003] The specific process of manufacturing tungsten-copper composite materials by melt infiltration is to first prepare a porous tungsten particle skeleton with a certain strength and density (i.e., the pre-sintering process), and then inject a metallic copper solution (i.e., the copper infiltration sintering process), so that it flows along the gaps between the tungsten particles under the action of capillary force and gravity and fills and wets the pores of the porous tungsten skeleton, thereby obtaining a relatively dense tungsten-copper composite material. Due to the expansion of application scenarios and the improvement of usage requirements, the density and mechanical properties of existing preparation methods cannot meet the existing high requirements. Therefore, it is necessary to prepare a tungsten-copper composite material with better physical and mechanical properties. At present, the tungsten-copper composite material prepared by the melt infiltration method has the characteristics of high density and excellent mechanical properties, which can meet more needs. Summary of the invention

[0004] The technical problems of the present invention are:

[0005] Due to the expansion of application scenarios and the improvement of usage requirements, the density and mechanical properties of existing preparation methods cannot meet the existing high requirements.

[0006] The objects of the present invention are:

[0007] It is necessary to prepare tungsten-copper composite materials with better physical and mechanical properties.

[0008] The technical solution of the present invention is:

[0009] On the one hand, the present invention provides a method for manufacturing a molten-infiltrated tungsten-copper composite material, comprising the following steps:

[0010] Step 1: Ingredients for ball milling: Ingredients are prepared according to the weight percentage of Ni: 0.7% ~ 1.0%, Cu: 2.4% ~ 2.6%, and the balance is W, and cemented carbide balls are added. The prepared materials and balls are placed in a ball mill for mixing to make the various powders evenly mixed;

[0011] Step 2: Add paraffin wax to the mixed powder in an amount of 2.5% to reserve a certain amount of pores for the inflow of copper liquid during copper infiltration and sintering;

[0012] Step 3: Press the tungsten copper column blank into a tungsten copper column blank using a hydraulic press under a pressure of 40T;

[0013] Step 4: Press the pure copper powder into a column blank using a hydraulic press under a pressure of 40T;

[0014] Step 5: Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min;

[0015] Step 6: pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min;

[0016] Step 7: stack the sintered column blank and the pure copper column blank in a molybdenum boat, with the pure copper column blank placed on top, and perform copper infiltration sintering in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min;

[0017] Step 8: Machining the copper-infiltrated column blank into a product that meets the requirements.

[0018] Preferably, the weight percentage is Ni: 0.75%, Cu: 2.5%, and the balance is W for mixing.

[0019] Preferably, the weight percentage is Ni: 1.0%, Cu: 2.5%, and the balance is W.

[0020] Preferably, the weight percentage is Ni: 0.25%, Cu: 2.5%, and the balance is W.

[0021] Preferably, the tungsten copper column blank is pressed by a hydraulic press under a pressure of 40T, with a blank mass of 510±5g, a blank diameter of 54.7±0.2mm, and a pressing height of 21±0.2mm;

[0022] Under a pressure of 40T, pure copper powder is pressed into a cylindrical blank using a hydraulic press. The mass of the pressed blank is 115±2g.

[0023] Preferably, W powder meets the requirements of GB / T3458-2006; Ni powder meets the requirements of GB / T7160-2017; Cu powder meets the requirements of GB / T5246-2007.

[0024] Preferably, the ratio of cemented carbide ball to material is 1.5:2, the ball material used is YG8, and the specification is φ10~φ15mm.

[0025] Preferably, the blank is buried in calcined alumina sand for sintering.

[0026] Preferably, the composite material has material properties of flexural strength ≥ 1200 MPa, Brinell hardness HBW ≥ 200, and density ≥ 15.35 g / cm3.

[0027] On the other hand, the present invention provides a melt-infiltrated tungsten-copper composite material, which is manufactured using the above-mentioned manufacturing method.

[0028] The advantages and beneficial effects of the present invention are:

[0029] The tungsten-copper composite material manufactured by the present invention adopts a melt infiltration method to manufacture the material, and the manufactured tungsten-copper composite material has good physical and mechanical properties. The manufacturing method of the present invention is simple and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. It is obvious that the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 Schematic diagram of the swing boat of the column blank during copper infiltration sintering. DETAILED DESCRIPTION

[0032] 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 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.

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] A method for manufacturing a melt-infiltrated tungsten-copper composite material, wherein the manufacturing process is mainly achieved through eight steps: ball milling, wax addition, tungsten-copper column pressing, copper column pressing, wax removal, pre-sintering, copper infiltration sintering, and mechanical processing. The tungsten-copper composite material manufactured by the present invention is a tungsten-copper composite material manufactured by the melt-infiltration method and has good physical and mechanical properties. The manufacturing method of the present invention is simple and has wide applicability.

[0035] Specifically, the method may include the following steps:

[0036] Step 1: Ingredients for ball milling: Ingredients are prepared according to the weight percentage of Ni: 0.7% ~ 1.0%, Cu: 2.4% ~ 2.6%, and the balance is W, and cemented carbide balls are added. The prepared materials and balls are placed in a ball mill for mixing to make the various powders evenly mixed;

[0037] Step 2: Add paraffin wax into the mixed powder at a dosage of 2.5%;

[0038] Step 3: Press the tungsten copper column blank into a tungsten copper column blank using a hydraulic press under a pressure of 40T;

[0039] Step 4: Press the pure copper powder into a column blank using a hydraulic press under a pressure of 40T;

[0040] Step 5: Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min;

[0041] Step 6: pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min;

[0042] Step 7: stack the sintered column blank and the pure copper column blank in a molybdenum boat, with the pure copper column blank placed on top, and perform copper infiltration sintering in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min;

[0043] Step 8: Machining the copper-infiltrated column blank into a product that meets the requirements.

[0044] Implementation Case 1:

[0045] ⑴ According to certain chemical composition and weight percentage, Ni: 0.75%, Cu: 2.5%, and the balance is W. After the raw materials are prepared, put them into a ball mill for powder metallurgy and mix them evenly;

[0046] ⑵ Add paraffin wax into the mixed powder at a dosage of 2.5%;

[0047] (3) Under 40T pressure, use a hydraulic press to press into a tungsten copper column blank, the pressed blank mass: 510±5g, pressed blank diameter: 54.7±0.2mm, pressed height: 21±0.2mm;

[0048] (4) Under 40T pressure, use a hydraulic press to press the pure copper powder into a column blank, the mass of the pressed blank is 115±2g;

[0049] ⑸ Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min;

[0050] (6) Pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min;

[0051] ⑺Put the sintered column blank and the pure copper column blank on a molybdenum boat (see attached Figure 1 ), the pure copper column blank is placed on the top and copper infiltrated and sintered in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min;

[0052] ⑻Machine the copper-infiltrated column blank into a product that meets the requirements.

[0053] The material performance was tested, and the test results were: flexural strength ≥1200Mpa, Brinell hardness HBW ≥200, density ≥15.35g / cm3.

[0054] Implementation Case 2:

[0055] ⑴ According to certain chemical composition and weight percentage, Ni: 1.0%, Cu: 2.5%, and the balance is W. After the raw materials are mixed, put them into a ball mill for powder metallurgy and mix them evenly;

[0056] ⑵ Add paraffin wax into the mixed powder at a dosage of 2.5%;

[0057] (3) Under 40T pressure, use a hydraulic press to press into a tungsten copper column blank, the pressed blank mass: 510±5g, pressed blank diameter: 54.7±0.2mm, pressed height: 21±0.2mm;

[0058] (4) Under 40T pressure, use a hydraulic press to press the pure copper powder into a column blank, the mass of the pressed blank is 115±2g;

[0059] ⑸ Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min;

[0060] (6) Pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min;

[0061] ⑺ Stack the sintered column blank and the pure copper column blank in a molybdenum boat, with the pure copper column blank placed on top, and perform copper infiltration sintering in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min;

[0062] ⑻Machine the copper-infiltrated column blank into a product that meets the requirements.

[0063] The material performance was tested, and the test results were: flexural strength ≥1200Mpa, Brinell hardness HBW ≥200, density ≥15.35g / cm3.

[0064] Implementation Case 3:

[0065] ⑴ According to certain chemical composition and weight percentage, Ni: 0.25%, Cu: 2.5%, and the balance is W. After the raw materials are prepared, put them into a ball mill for powder metallurgy and mix them evenly;

[0066] ⑵ Add paraffin wax into the mixed powder at a dosage of 2.5%;

[0067] (3) Under 40T pressure, use a hydraulic press to press into a tungsten copper column blank, the pressed blank mass: 510±5g, pressed blank diameter: 54.7±0.2mm, pressed height: 21±0.2mm;

[0068] (4) Under 40T pressure, use a hydraulic press to press the pure copper powder into a column blank, the mass of the pressed blank is 115±2g;

[0069] ⑸ Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min;

[0070] (6) Pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min;

[0071] ⑺ Stack the sintered column blank and the pure copper column blank in a molybdenum boat, with the pure copper column blank placed on top, and perform copper infiltration sintering in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min;

[0072] ⑻Machine the copper-infiltrated column blank into a product that meets the requirements.

[0073] The material performance was tested, and the test results were: flexural strength ≥1200Mpa, Brinell hardness HBW ≥190, ​​density ≥15.35g / cm3.

[0074] It should be noted that the above-mentioned process operations can be applied in combination to different degrees. For the sake of simplicity, the implementation methods of various combinations are not described in detail. Technical personnel in this field can flexibly adjust the order of the above-mentioned operating steps according to actual needs, or flexibly combine the above-mentioned steps.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing a tungsten-copper composite material by infiltration, characterized in that: The following steps are involved: Step 1: Ingredients for ball milling: Ingredients are prepared according to the weight percentage of Ni: 0.7% ~ 1.0%, Cu: 2.4% ~ 2.6%, and the balance is W, and cemented carbide balls are added. The prepared materials and balls are placed in a ball mill for mixing to make the various powders evenly mixed; Step 2: Add paraffin wax to the mixed powder in an amount of 2.5% to reserve a certain amount of pores for the inflow of copper liquid during copper infiltration and sintering; Step 3: Press the tungsten copper column blank into a tungsten copper column blank using a hydraulic press under a pressure of 40T; Step 4: Press the pure copper powder into a column blank using a hydraulic press under a pressure of 40T; Step 5: Dewax the pressed tungsten copper column blank in a push rod dewaxing furnace, the dewaxing temperature is 800℃~900℃, and the pushing speed is 4.0~6.0mm / min; Step 6: pre-sinter the pressed tungsten copper column blank in a continuous hydrogen sintering furnace at a sintering temperature of 1100°C to 1200°C and a pushing speed of 4.5 to 6.5 mm / min; Step 7: stack the sintered column blank and the pure copper column blank in a molybdenum boat, with the pure copper column blank placed on top, and perform copper infiltration sintering in a continuous hydrogen sintering furnace at a sintering temperature of 1500°C to 1700°C and a pushing speed of 4.5 to 6.5 mm / min; Step 8: Machining the copper-infiltrated column blank into a product that meets the requirements.

2. The method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In step 1: The weight percentage is Ni: 0.75%, Cu: 2.5%, and the balance is W.

3. The method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In step 1: The weight percentage is Ni: 1.0%, Cu: 2.5%, and the balance is W.

4. The method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In step 1: The weight percentage is Ni: 0.25%, Cu: 2.5%, and the balance is W.

5. The method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In steps 3 and 4: Under 40T pressure, a hydraulic press is used to press the tungsten copper column blank. The pressed blank mass is 510±5g, the pressed blank diameter is 54.7±0.2mm, and the pressed height is 21±0.2mm. Under a pressure of 40T, pure copper powder is pressed into a cylindrical blank using a hydraulic press. The mass of the pressed blank is 115±2g.

6. The method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In steps 3 and 4: W powder meets the requirements of GB / T3458-2006; Ni powder meets the requirements of GB / T7160-2017; Cu powder meets the requirements of GB / T5246-2007.

7. A method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In step 1: The carbide ball and material ratio is 1.5:2, the ball material used is YG8, and the specification is φ10~φ15mm.

8. A method for manufacturing a tungsten-copper composite material according to claim 1, characterized in that: In the steps 6 and 7, the blank needs to be buried in calcined alumina sand for sintering.

9. A method for manufacturing a tungsten-copper composite material according to any one of claims 1 to 8, characterized in that: In step 8: Composite material, the material properties of which are bending strength ≥1200Mpa, Brinell hardness HBW ≥200, and density ≥15.35g / cm3.

10. A tungsten-copper infiltration composite material, characterized in that: The method is manufactured by any one of claims 1 to 9.

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