Production process of tungsten-copper alloy

The technical process of preparation of tungsten-copper alloy by powder metallurgy is made by mixing of powder ingredients and limited forming and sintering. Tungsten-copper or molybdenum-copper powder was sintered in liquid phase at 13001500° after limited molding. The uniformity of the materials prepared by this method is not good, there are many closed Spaces, and the fine density is generally lower than 98%. However, by adding a small amount of nickel to the activated sintering method, mechanical alloying method or oxide recovery method, the preparation of ultrafine and nano powders can improve the sintering activity, and then improve the fine density of tungsten-copper and molybdenum-copper alloys. However, the conductive and thermal functions of the material decreased significantly due to nickel activation sintering, and the conduction function of the material also decreased due to the introduction of impurities in mechanical alloying. The process of preparing powder by oxide co-recovery method is complicated and the processing power is low.

1, injection molding method injection molding method into high density tungsten alloy. The production method is to mix nickel powder, copper tungsten powder or iron powder of uniform particle size of 15 microns with tungsten powder of particle size of 0.52 microns and 515 microns, and then mixed into 25%30% organic binder (such as white wax or polymethyl acid vinegar) injection mold, steam cleaning and light method to remove the adhesive, sintering in the medium to obtain high density tungsten alloy.

2, copper oxide powder method copper oxide powder (mixed and ground back to copper) rather than metal copper powder, copper alloy in the sintered pressed billet form a matrix, tungsten as a strengthening frame. The high expansion component is limited by the second component around, and the powder is sintered in wet at a lower temperature. The selection of very fine powder can improve the sintering function and fineness, so that it can reach more than 99%.

3, tungsten, molybdenum skeleton penetration method will first tungsten powder or molybdenum powder limited molding, and sintering into a tungsten, molybdenum skeleton with certain porosity, and then copper penetration. This method is suitable for tungsten copper, molybdenum copper products with low copper content. Compared with tungsten-copper, molybdenum-copper has the advantages of small mass, simple production, line expansion coefficient, thermal conductivity and some primary mechanical functions are suitable for tungsten-copper. Although the heat resistance function is not as good as tungsten copper, but better than some heat resistant materials, so the use prospect is better. Due to the poor wettability of molybdenum-copper than tungstan-copper, especially in the preparation of molybdenum-copper with low copper alloy content, the fine density of the material after melting is low, resulting in the material's air tightness, electrical conductivity and thermal conductivity can not meet the requirements, and its use is limited.