An investigation on morphology and structure of Cu–Cr alloy powders prepared by mechanical milling and alloying

Abstract

A method combined with mechanical milling (MM) and mechanical alloying (MA) was performed to prepare nanocrystal Cu–Cr supersaturated solid solution from commercially available powders. Cu and Cr powders were pre-milled separately by MM for 20h, and then mechanically alloyed with as-received Cr and Cu powders respectively in a wet condition for 100h. The morphology and structure of the samples were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique respectively. Compared with MA without pre-milling and pre-milling of Cu, MA of pre-milled Cr and as-received Cu mixtures could produce finer alloy powders with higher powder yield, narrower range of size distribution, smaller crystallite size and higher dissolution of Cr, which will show desirable properties after subsequent consolidation and present an attractive potential for technological applications. The mechanical alloying mechanisms including morphological changes, crystallite refinement and solid solubility extension were discussed to explain the phenomena during the fabrication process.