Tungsten Copper Fine-grain Liner Fabricating Process (2/2)

In these composite materials, tungsten copper is the most ideal material for the liner. Tungsten copper alloy is Cu difference between two kinds of physical and chemical properties of W and face-centered cubic structure of the body-centered cubic structure is neither large nor the formation of pseudo alloy intermetallic compounds. It not only has high hardness, high strength, high density, low thermal expansion coefficient and excellent abrasion resistance of W and also has plasticity and excellent electrical and thermal conductivity of Cu. Tungsten jet head with a higher speed, when penetrating armor can shorten the time through, thereby facilitating against reactive armor. But it is brittle and the powder adhesion is poor, the added copper powder with good ductility can contribute to the shaping process and improve the jet stability, avoid breaking.

However, tungsten copper alloy material prepared by the conventional powder metallurgy method, since good metal powder flowability and there are many random factors hard to be controlled in mechanized packing, press-forming and other processes, it will cause some problems, such as coarse grains, poor uniformity and density distribution, depth fluctuations, which can not meet the requirements of the weapon. In addition, the tungsten copper composite liner is very sensitive to the height of burst; under the big height of burst the penetration depth has a rapid decline and the ideal height of burst is 3 times than the diameter.

This is also the commonness of composite liner, which means under small height of burst, the armor depth increase by 30% than the pure copper liner, but under big height of burst it is difficult to obtain the good jet ductility. For the reason, the researchers have proposed a kind of new process that spray pyrolysis milling – wet milling – liquid-phase sintering to fabricate tungsten copper liner. Wherein the spray pyrolysis milling precipitated nano-scale tungsten phase approximately spherical and uniformly distributed on the Cu substrate, improving both activity; wet ball milling can reduce the powder oxidation and prevent metal grains from gathering and growing; liquid-phase sintering is beneficial for higher densification and better uniformity.

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