Microstructural and mechanical properties of Cu-7vol.%ZrB ₂ alloy produced by powder metallurgy techniques

Abstract The Cu-7vol.%ZrB ₂ alloy examined in this study was consolidated via powder metallurgy (PM) processing by combining mechanical alloying and hot pressing. Powder mixture with composition: 94.78 wt.% copper, 4.1 wt.% zirconium, and 1.12 wt.% boron was used as a starting material. Mechanical alloying of powder mixture was performed at various times: 5, 10, 15, 20, 25, and 30 h. Structural changes that occur in the samples of copper alloy with 7vol.%ZrB ₂ after milling and during hot pressing process were studied with the use of X-ray diffraction. Scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometry (EDS) was applied to examine the morphological properties and elemental analysis of the hot-pressed samples as a function of milling times. Also, hardness of the Cu-7vol.%ZrB ₂ alloy was investigated, and the results showed that hardness of the samples increased as the milling time increased. The compressive properties at room temperature are correlated to the corresponding hardness results. Distribution of ZrB ₂ particles and presence of agglomerates in the Cu matrix directly depend on the milling time and show strong influence on compressive properties and fracture of Cu-7vol.%ZrB ₂ alloy.