Copper-zirconium alloys with high conductivity were produced using powder
metallurgy. Two-steps manufacturing process, containing mechanical alloying
followed by hot pressing, was applied in achieving improved mechanical and
physical properties of Cu-Zr alloy. In this paper, the influence of boron on
Cu-Zr alloys properties was studied on Cu-1Zr (wt.%) and Cu-1.1Zr-0.3B
(wt.%) systems. Scanning electron microscopy, laser nanoparticle sizer,
computed tomography and X-ray diffraction were employed for observation of
changes in the microstructure during production steps. More specifically -
variations in size of the Cu particles, powder mixtures? structural
parameters, and development of CuZr phase in binary alloy, CuZr phase and
ZrB2 particles in ternary alloy were observed. It was shown that presence of
boron increases dislocation density in ternary alloy over the mechanical
alloying time compared to binary alloy. The results presented in this study
show higher hardening effect in Cu-Zr- B alloy compared to Cu-Zr alloy,
resulting in stable hardness values during thermomechanical treatment.
Further, it can be seen that finely dispersed reinforcing ZrB2 particles in
copper matrix does not have significant influence on its conductivity.
Moreover, both systems Cu-Zr and Cu-Zr-B exhibit better electrical
conductivity after thermomechanical treatment as a result of zirconium
reduction in solid solution due to its precipitation.