High temperature fracture behavior of tungsten fiber reinforced copper matrix composites under dynamic compression

Wf/Cu82Al10Fe4Ni4 composite was fabricated by flow casting method. Dynamic compression tests with strain rate of 1600 s−1 at 20 °C, 200 °C, 400 °C and 600 °C were finished by means of Split Hopkinson Pressure Bar (SHPB). The results showed that the composites possessed obvious high temperature softening behaviors. The damages of Wf/Cu82Al10Fe4Ni4 composites all occurred within the tungsten fibers when compressed at 20 °C, 200 °C and 400 °C, indicating that the interface strength of the composites was high. While the damages of the composites occurred either in the tungsten fibers or in the matrix at 600 °C, in addition, the melt of matrix alloy also occurred. Microstructure of the composites after dynamic compressing at 600 °C was analyzed by transmission electron microscope (TEM), observation revealed that there were a lot of high-density dislocations, stacking faults and twins existing in the matrix. It was also found that the precipitated phase in the matrix played the role of the second phase strengthening.

► Interface strength of the composites was high.
► The composites possessed obvious high temperature softening behavior.
► Damage of the composites occurred in different location, when temperature changed.
► Stacking faults and twins occurred in the composites at 600 °C.