No abstract

W-30 wt.% Cu nanocomposites were prepared by chemical reduction of a ball-milled WO3-CuO powder mixture under a hydrogen atmosphere. The prepared samples were analyzed by means of X-ray diffraction, transition electron microscopy, scanning electron microscopy and energy dispersed spectroscopy. Microstructural studies revealed higher density of the composite sintered at 1300 °C compared to 1 050 °C and 1 150 °C due to activated liquid phase sintering as well as the solution-reprecipitation mechanism at 1300 °C. Density and hardness of the W-Cu composite samples measured in the range of 87.5- 97.3 g cm-3 and 22 - 63 Rockwell A, respectively. It was also found that the wear mechanism of the composite includes the following steps: chipping of tungsten particles, plastic deformation of copper phase and formation of some Cu-free pores and micro-cracks, pulling out of tungsten particles and plastic strain and deformation of tungsten particles and formation of a mechanically mixed layer on the surface.

W-30 wt.% Cu nanocomposites were prepared by chemical reduction of a ball-milled WO3-CuO powder mixture under a hydrogen atmosphere. The prepared samples were analyzed by means of X-ray diffraction, transition electron microscopy, scanning electron microscopy and energy dispersed spectroscopy. Microstructural studies revealed higher density of the composite sintered at 1300 °C compared to 1 050 °C and 1 150 °C due to activated liquid phase sintering as well as the solution-reprecipitation mechanism at 1300 °C. Density and hardness of the W-Cu composite samples measured in the range of 87.5- 97.3 g cm-3 and 22 - 63 Rockwell A, respectively. It was also found that the wear mechanism of the composite includes the following steps: chipping of tungsten particles, plastic deformation of copper phase and formation of some Cu-free pores and micro-cracks, pulling out of tungsten particles and plastic strain and deformation of tungsten particles and formation of a mechanically mixed layer on the surface.