The effect of interface modification on fracture behavior of tungsten fiber reinforced copper matrix composites

Wf/Cu composites, Wf(Ni)/Cu composites and Wf/Cu82Al10Fe4Ni4 composites were fabricated by penetrating casting method. Bending strength and dynamic compressive strength of the composites were tested. Fracture mode and microstructure were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The result showed that the interface strength of Wf(Ni)/Cu composites and Wf/Cu82Al10Fe4Ni4 composites were higher than Wf/Cu composites. In Wf(Ni)/Cu composites, nickel plated on the surface of tungsten fibers has diffused into the inner of tungsten fibers, and a large number of tungsten grains and Ni4W intermetallic compounds appeared within tungsten fibers. In Wf/Cu82Al10Fe4Ni4 composites, Fe–Ni solid solutions precipitated on the interface between matrix and tungsten fibers, and tungsten has diffused into the Fe–Ni solid solutions. Dynamic compression test showed that the dynamic compressive strength and plasticity of Wf/Cu82Al10Fe4Ni4 composites were highest among the three kinds of composites.

► Interface strength of Wf/Cu composites can be enhanced by means of plating Ni on tungsten fiber.
► There exists recrystallization of tungsten fibers in Wf(Ni)/Cu composites.
► Interface strength of Wf/Cu composites can be enhanced by means of adding Fe, Ni and Al in matrix.
► Fibrous structure within original tungsten fibers is kept in Wf/Cu82Al10Fe4Ni4 composites.