关键词: 特种加工工艺, 选区激光烧结, 液相烧结, 多组分铜基金属粉末

Abstract: Selective laser sintering (SLS) of a self-developed multi-component Cu-based metal powder is investigated. The powder system consists of a mixture of pure Cu powder, pre-alloyed CuSn and CuP powder. The experimental results demonstrate that choosing suitable laser processing parameters and layer thickness can effectively control "balling" effect and curling deformation in laser sintering of this powder system. The X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to analyze the structural phase, surface morphology and microstructure of the laser-sintered sample. It shows that the bonding mechanism of this multi-component Cu-based metal powder is liquid-phase sintering. The binder CuSn melts and infiltrates into the pores between the Cu particles and solidifies to form sintering necks, which sufficiently bond the structural metal Cu. The element phosphorus acts as flux and reacts with oxygen to form CuPO₃ in SLS process, which prevents the Cu particles form oxidation. A case study on SLS of this Cu-based metal powder to fabricate a gear is carried out. 82% relative theoretical density and transverse dimension error of 1.9% are achieved.

Key words: non-traditional machining, selective laser sintering, liquid-phase sintering, multi-component Cu-based metal powder