Tungsten copper liner is considered as the heart of ammunition,
which not only has high hardness, high strength and low coefficient of thermal
expansion of W, but also has good plasticity and excellent thermal and
electrical conductivity of Cu. Compared with single metal liner, this kind of
composite liner has many advantages, such more reasonable energy conversion and
absorption mechanism, fuller utilization of chemical energy, better performance
in armor, lower cost, a broader application prospect and so on. With the
production technology and process innovation, dense liner gradually is replaced
by powder liners.
Since tungsten copper powder liner has high density, good
ductility, deep penetration, less plugging and other advantages, it has been
play an important role in shaped charge and some military fields. But in the
process of tungsten copper liner, with the increasing temperature, Cu loss is
always an inevitable problem. Cu loss will reduce the density and strength of
materials. Related researchers based on pressure
pressing, sintering temperature and time factors on the rate of variation of
copper analyzed, and summed up the impact of copper and relative density on jet
liner properties for the preparation of tungsten-copper powder liner offers
theoretical basis. The experiments show that he rate of copper sintered samples
with the pressing pressure increases with increasing sintering time and
sintering temperature decreases, Cu loss is opposite. This is due to:
1. The pressure increases effectively narrows the distance of W
grains, which reduces the Cu loss from the inside and slows internal material
Cu particles outward evaporation rate;
2. The increasing pressure enlarges the contact
area of Cu surface that the original Cu particles have a larger free energy in
the melting process is easier and the adjacent Cu particles fuse to form larger
particles. And it reduces the volatile rate of fine particles at high
temperature that the content of Cu remained stable. Therefore, the content of
Cu impact on the jet penetration is significant less than the relative density,
but plays an important role in the stability of the jet. The smaller the rate
of copper loss, the liner jet penetration is more stable.
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