三维金属零件的电子束选区熔化成形

针对电子束选区熔化成形技术中金属粉末在高能电子束作用下容易溃散的特点,进行不同形状的316L不锈钢粉末的成形研究,得出既不溃散又具有较好成形性的粉末配比.针对成形过程中成形区域的温度场分布特点,提出成形件旋转法和多连通区域零件的薄层切割法,能较好地解决成形件第一条扫描线球化和成形区域不同部位所需温度不相同的问题,简化CAD模型的数据处理过程.在材料研究和工艺研究的基础上,制造出三维金属零件,层间为完全冶金结合,层内没有未熔颗粒和空洞,组织结构为均匀细小的蜂窝状枝晶组织,水平和垂直拉伸试样的极限强度和断后伸长率为600 MPa、40%和560 MPa、35%.

PRODUCED THREE-DIMENSIONAL METAL PARTS BY ELECTRON BEAM SELECTIVE MELTING

Aimed at the problem that metal powder is easily break out of the powder bed under the action of high-energy electron beam, two kind shapes of 316L stainless steel powder are investigated, and the mixture powder which has the good forming ability and high counteract ability again the high-energy electron beam are gained. Aimed at the character-istic of temperature field during electron beam selective melt-ing ( EBSM ), the rotating and slicing methods of multi-connect areas are adopted, which not only solve the problem of first line scan balling and the matching between the regions of the part and the temperature distribution, but also simplify the data processing of CAD model. Under the research on the materials and scanning methods, some three-dimensional parts are manufactured, the interfaces between the layers are fully met-allurgical bonding, no unmelted particle and voids are founded in the part, the microstructure of the three-dimension forming parts are fine and cellular dendrites. The ultimate strength and elongation of the parallel and the vertical testing samples are 600 MPa, 40 / and 560 MPa, 35 /, respectively.