精铸型壳的增材制造技术研究进展

增材制造技术用于精密铸造领域,可以满足市场对精密铸件的短周期、个性化、多样化、柔性制造的需求.增材制造技术可以制作树脂模型代替蜡模进行精密铸造,但更高效的方法是用增材制造技术直接制备精铸型壳.目前可用于制备精铸型壳的增材制造技术主要有三维打印法(3DP)、选择性激光烧结法(SLS)、光固化成形法(SLA)以及浆料挤出法.介绍了这几种增材制造技术的原理和研究进展,其中3DP法围绕粘结剂用量、后处理工艺展开研究,制备的型壳表面粗糙度高、致密度低;SLS法围绕粘结剂、粉末粒径、打印参数展开研究,制备的型壳表面质量好、力学性能高,容易出现过烧缺陷;SLA法围绕浆料制备、光敏树脂去除展开研究,制备的型壳理论精度高、后处理困难;浆料挤出法围绕浆料挤出性能、设备完善展开研究,制备的型壳致密度高,表面质量较差.

Research Progress of Additive Manufacturing Technology for Investment Casting Ceramic Shell

The application of additive manufacturing (AM) technology in the precision casting process can meet the market demand for short cycle, personalized, diversified and flexible manufacturing of precision castings. The AM technology can fabricate ceramic shell by using polymer parts instead of wax patterns for investment casting, but a more efficient method is to directly prepare investment casting ceramic shell by additive manufacturing technology. Additive manufacturing technologies that can be used to prepare investment casting ceramic shell mainly include three-dimensional printing (3DP), selective laser sintering (SLS), stereo lithography apparatus (SLA), and slurry extrusion. The work introduced the technological principles and research progress of these technologies. The 3DP process mainly researches the amount of binder and post-treatment process. The shell prepared by 3DP process has high surface roughness and low density. The SLS process mainly researches binder, powder particle size and printing parameters. The shell prepared by SLS process has good surface quality and high mechanical properties, and is prone to overburning defect. The SLA process mainly researches slurry preparation and photosensitive resin removal. The shell prepared by SLA process has high theoretical accuracy and post-treatment difficulty. The slurry extrusion process mainly researches slurry extrusion performance and equipment improvement. The shell prepared by slurry extrusion process has high density and poor surface quality.