A method for improving the bonding surface strength of copper tungsten and copper

Abstract

The invention discloses a method for improving the strength of the joint surface between copper, tungsten and copper, and relates to the technical field of manufacturing products from metal powder, including S1. Powder loading: firstly, tungsten powder and copper powder are prepared according to the mass percentage of tungsten powder of 5%-95%. Form copper-tungsten composite powder, and then put the configured composite powder into the graphite crucible for preparing copper-tungsten alloy; S2, compaction: use stainless steel pressing plate to compact the copper-tungsten composite powder placed in the graphite crucible, S3 1. Powder spreading: Copper powder is spread on the top of the copper-tungsten composite powder billet, and then the copper powder is compacted; S4. Sintering: Put the graphite crucible with the copper powder billet into the discharge plasma sintering furnace, and vacuumize the furnace At the same time, mechanical pressure is applied to the copper-clad powder blank, and the copper-tungsten alloy with a copper-clad layer is obtained with the furnace cooling; the method of the invention can improve the tensile strength of the joint surface while ensuring the conductivity of the tungsten-copper contact.

Description

technical field [0001] The invention relates to the technical field of manufacturing products from metal powder, in particular to a method for improving the strength of the bonding surface between copper tungsten and copper. Background technique [0002] Tungsten copper alloy is an alloy composed of tungsten and copper. Commonly used alloys contain 10% to 50% copper. The alloy is prepared by powder metallurgy, which has good electrical and thermal conductivity, good high temperature strength and certain plasticity. At a very high temperature, such as above 3000°C, the copper in the alloy is liquefied and evaporated, absorbing a large amount of heat and reducing the surface temperature of the material. So this kind of material is also called metal sweating material. [0003] Since tungsten and copper are immiscible with each other, tungsten copper alloy has low expansion, wear resistance, corrosion resistance of tungsten and high electrical and thermal conductivity of copp...

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Problems solved by technology

[0004] Because of its good electrical conductivity and tensile strength, copper-tungsten alloys are mostly used in the field of electronic products or high-voltage electrical contacts. The national standard GB / T 8320 copper-tungsten and silver-tungsten electrical contacts stipulates: "Copper-tungsten integral electrical contacts The tensile strength of the joint surface between the copper-tungsten alloy of the contact and the conductive end is not less than 185MPa" when the conductive end is copper; however, due to the limitations of the current sintering process and sintering equipment, the joint surface between copper-tungsten and copper cannot be used during the sintering process. To avoid the presence of impurities, oxides, etc., it is difficult to control the tensile strength of the CuW / Cu joint surface above 185Mpa, and the production cycle is long

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