作　　者： ; ;

机构地区： 华南理工大学机械与汽车工程学院

出　　处： 《机械工程学报》 2007年第8期175-180,共6页

摘　　要： 研究激光、铺粉、扫描三个重要选区激光熔化子系统的技术要点。通过计算成形过程所需激光能量,确定激光器的选用。研究表明成形升降台的连续下降精度、铺粉辊的回转偏心量及径向跳动量都对实现最小铺粉厚度控制有着重要影响。结合扫描速度对比试验,分析扫描系统的扫描特征,认为采用快的扫描速度是选区激光熔化工艺的一个重要特点,此外应采用合适的扫描策略克服热变形。在上述研究基础上,采用铜基合金粉末进行三维金属实体成形试验,试验分析表明,成形实体是一个由等轴晶和枝晶组成,相对密度达95%,具有冶金结合组织的金属实体,尺寸精度为±0.5 mm。所获得的成形实体多层断面构造、铺粉、扫描特征等信息可证实部分技术要点分析。 The key points of the three main subsystems of selective laser melting （SLM） rapid prototyping system such as the laser, the powder delivering and the scanning systems, are studied through calculation of the needed laser energy during SLM processing. The selection of laser to be used is confirmed. It is found that the accuracy of the cylinder movement, the ec- centricity and interval in the radial run-out of the roller have important influences on the control of minimal layer thickness. Combined with an experiment of selective melting of metal powder at varying scanning speeds, the scanning performance is analyzed, and the result shows that fast scanning speed and proper scanning strategy should be used during SLM processing to avoid thermal deformation. Based on above research work, an experiment for producing metal part using Cu-based powder is carried out. The result shows the part is metallurgical bonded entity with density of 95%, dimension precision of ± 0.5 ram, and the micmstructure of the part is composed of equiax and dendritic crystal. The cross section and the shape of the SLM part, the processing parameters such as layer thickness and scanning speed, demonstrate the key points of SLM technique.

关 键 词： 选区激光熔化 快速成形 金属零件 冶金结合

领　　域： [机械工程] [金属学及工艺] [一般工业技术] [金属学及工艺]