Laser sintering of Cu-Zr-ZrB2 composite

Abstract

Cu-4.1Zr-1.1B (wt%) composite has been synthesized by mechanical alloying, cold pressing of mechanically alloyed powders and, for the first time in literature, sintering by laser irradiation (pulsed, millisecond Nd: YAG laser was employed) in nitrogen atmosphere. The influence of different sintering parameters on the properties of laser-sintered materials was investigated. Microstructural changes during laser sintering were studied using scanning electron microscopy and X-ray diffraction. Rapidly solidified structure, as well as the presence of ZrB2 particles and metastable CuZr phase, which are a product of laser sintering, affected higher degree of copper matrix hardening which was retained up to high temperatures. In general, laser sintering of Cu-4.1Zr-1.1B (wt%) green compact using the parameters: laser frequency 3 Hz, laser pulse duration 8 ms, pulse energy similar to 19 J, number of scans 4 yields the optimum combination of high density, microhardness and electrical conductivity. (C) 2014 Elsevier B.V. All rights reserved.