Microstructural and mechanical properties of Cu-7vol.%ZrB2 alloy produced by powder metallurgy techniques

Abstract

The Cu-7vol.%ZrB2 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.%ZrB2 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.%ZrB2 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 ZrB2 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 Cu7vol.%ZrB2 alloy.