Effects of boron and chromium carbide on impact wear and corrosion behavior of copper composites produced by powder metallurgy

In this study, the effects of boron (B) and chromium carbide (Cr 3 C 2 ) reinforcements on the impact wear and corrosion behaviour of copper-based composites produced by powder metallurgy were investigated. Composites containing 0, 5 and 10 wt.% reinforcement were characterised using X-ray diffraction, scanning electron microscope–energy-dispersive X-ray spectroscopy, optical microscopy and three-dimensional profilometry. Impact wear tests were performed under cyclic loading conditions of 10,000 and 100,000 cycles at 2.0 and 3.0 Hz, while corrosion performance was evaluated in 3.5 wt.% NaCl solution using potentiodynamic polarisation. The CuBCr5 composite exhibited the lowest volume loss under the investigated impact wear conditions, with a minimum value of 0.030 mm 3 and a value of 0.200 mm 3 under the most severe condition. In addition, CuBCr5 showed the best corrosion resistance, with a corrosion rate of 0.808 mpy and a corrosion current density of 2.00 µA/cm 2 . These improvements were attributed to improved densification, grain refinement, more homogeneous reinforcement distribution and the possible development of a more stable protective surface layer. Although reinforcement addition reduced the electrical conductivity compared with Pure Cu, the CuBCr5 composite maintained a more stable conductivity response than CuBCr10 within the investigated frequency range. Overall, the results indicate that 5 wt.% B–Cr 3 C 2 reinforcement provides the most balanced combination of impact wear resistance, corrosion resistance and electrical response in Cu-based composites.