基于SLS的叶轮精密铸造工艺及性能

Research on Precision Casting Process and Performance of Impeller Based on SLS

为提升叶轮零件的铸造质量,将3D打印模样与石膏型精密铸造相结合,对模样的成型位置及浸蜡工艺进行分析,利用选区激光烧结技术(SLS)制得高质量叶轮模样,基于顺序凝固和排气优良设计顶注式横浇道–内浇道式浇注系统,经ProCAST软件模拟验证设计方案的合理性,最后通过真空加压浇注成功得到合格铸件,并分析T5热处理对铸件力学性能的影响。结果表明:SLS可与石膏型铸造良好结合,3D打印模样的力学性能取决于受力面是否为打印面,浸蜡可明显提升模样的力学性能;铸件经T5热处理后,其抗拉强度和布氏硬度分别从184 MPa和57 HB上升至330 MPa和109 HB,共晶硅的熔断和钝化是力学性能提升的主要原因。

In this paper,3D printing pattern is combined with plaster precision casting to improve the casting quality of impeller parts.The molding position and wax dipping process of the pattern were analyzed.The high quality impeller pattern was prepared with selective laser sintering(SLS).Based on the excellent sequential solidification and exhaust,a top-pouring gating system was designed,and the design scheme was simulated with ProCAST software to verify the rationality.Then,qualified castings were successfully obtained with vacuum pressure pouring,and the influence of T5 heat treatment on the mechanical properties of castings was studied.The results show that SLS can combine well with plaster precision cast-ing.The mechanical properties of 3D printing patterns depend on whether the stress surface is the printing surface.Wax dipping process can significantly improve the mechanical properties of the patterns.After T5 heat treatment,the tensile strength and Brinell hardness of the casting increase from 184 MPa and 57 HB to 330 MPa and 109 HB,respectively.The melting and passivation of eutectic Si are the main factors for the improvement of mechanical properties.