激光快速制造中的组织结构不均匀性分析

结合快速成型研究趋势，进行了金属粉末的激光快速制造试验，深入探讨了制件内部的组织结构不均匀现象。研究表明：金属材料的激光快速制造制件内部，随激光作用次数的不同，制件层组织糙化，并由均匀微米级等轴晶结构向树枝状结晶结构转化。相邻层的结合界面上，材料组织由细小等轴晶、较为粗大的板条状结构与枝晶组成。

Study on Microstructure Unevenness of Production by Laser Rapid Manufacturing

According to the development of rapid prototyping, fundamental experiments on rapid manufacturing of metallic parts by high power CO2 laser were carried out and the microstructure unevenness of the production was discussed systemically. It is indicated that with the increasing of scanning times by laser, the layer microstructure of the production are coarsened. At the same time, the internal microstructure of the production layer change from micron equiaxed crystal to dendrite crystal, the microstructure of the interface of two neighboring layers is consisted of ultra fine equiaxed crystals, coarser lathing structures and dendrite crystals.