Effect of the Q‐switch parameters on the sintering behavior of laser micro sintering Cu‐based metal powder using Q‐switched Nd‐YAG laser

Abstract

Purpose -The purpose of this paper is to investigate the effect of the Q-switching parameters on the sintering behavior of laser micro sintering Cu-based metal powder, using Q-switched 1064 nm Nd-YAG laser. Design/methodology/approach -An experimental study has been performed. Metal powder mixture with Cu and Cu-P alloy powders has been utilized. Q-switching duration of 15 ms , 25 ms, rate of 25 kHz , 45 kHz have been used. Findings -The results show that as the Q-switching rate and duration increases, the peak laser power decreases and the densification enhances. However, an optimal peak laser power exists and if the peak laser power is too low, the density of the sample is also low. The densification regime of laser micro-sintering is not only caused by the liquid phase filling the pores, but is also caused by the Cu powder migrating and by coalescence, e.g. including initial stage and intermediate stage of the traditional furnace liquid phase sintering. However, the degree of these stages depends on the peak power and input laser energy. Originality/value -The effect of the Q-switching parameters on sintering behavior of laser micro sintering Cu-based metal powder using Q-switched 1064 nm Nd-YAG laser has been obtained. It is found that the densification behavior is Q-switching parameters dependent, although the average laser power is same. The densification regime of laser micro-sintering includes initial stage and intermediate stage of the traditional furnace liquid phase sintering, but the degree is Q-switching parameters dependent.

A finite element model of thermal evolution in laser micro sintering

“…The resolution and surface roughness obtained by this new technology was more than one order of magnitude better than those fabricated by conventional selective laser sintering (SLS) process [2]. Therefore, LMS attracted more and more attention in these years [3,4]. During the LMS process, a powder layer thin as tens of micrometers is laser-scanned to fuse the two-dimensional slice to an underlying solid piece, which consists of a series of stacked and fused two-dimensional slices.…”