( 1. 南京航空航天大學(xué) 材料科學(xué)與技術(shù)學(xué)院， 南京 210016；
2. 中國工程物理研究院 機(jī)械制造工藝研究所， 綿陽 621900)
摘 要: 研究了選區(qū)激光燒結(jié)專用多組分銅基金屬粉末（組分包括純Cu， 預(yù)合金CuSn， CuP）的燒結(jié)性能。結(jié)果表明， 通過合理控制激光工藝參數(shù)（特別是激光功率和掃描速率）， 能順利實(shí)現(xiàn)粉末燒結(jié)成形， 且無明顯的“球化”效應(yīng)和翹曲變形。 掃描電鏡和X射線衍射分析證實(shí)， 此組粉末體系的激光燒結(jié)是基于液相燒結(jié)機(jī)制， 其中熔點(diǎn)較低的CuSn充當(dāng)粘結(jié)金屬，熔點(diǎn)較高的Cu充當(dāng)結(jié)構(gòu)金屬； 而添加元素P則起稀釋劑的作用， 能避免Cu顆粒表面氧化。 研究了粉末體系中粘結(jié)金屬含量對粉末燒結(jié)致密化和燒結(jié)件微觀組織的影響。 結(jié)果表明， 在一定范圍內(nèi)粘結(jié)金屬含量的提高有利于改善燒結(jié)致密度；但若粘結(jié)金屬過量， 則會(huì)因“球化”效應(yīng)而降低致密度。
關(guān)鍵字: 快速原型制造；選區(qū)激光燒結(jié)； 銅基金屬粉末； 液相燒結(jié)； 添加劑
（ 1. College of Materials Science and Technology,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. Institute of Machinery Manufacturing Technology,
China Academy of Engineering Physics, Mianyang 621900, China）
Abstract: Selective laser sintering of a special multi-component Cu-based metal powder which consists of high-purity Cu, pre-alloyed CuSn and CuP was processed. The experimental results show that choosing suitable laser processing parameters, especially laser power and scanning rate, can effectively control “balling” effect and curling deformation during laser sintering. The scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses show that the bonding mechanism of this process is liquid phase sintering, during which the Cu powder with higher melting point acts as the structure metal; while the CuSn powder with lower melting point acts as the binder. The element phosphorus acts as fluxing agent to react with oxygen, preventing the Cu particles form oxidation. The influence of the content of binder in powder system on the densification and attendant microstructural features of the sintered samples was investigated. It is found that with the increase of the binder content, the microstructures become denser; however, an excess of binder results in “balling” phenomena, hence damaging the densification.
Key words: rapid prototyping; selective laser sintering; Cu-based metal powder; liquid-phase sintering; additive
