激光增材制造砂型涂料涂覆工艺研究

Study on coating process of sand mold by laser additive manufacturing

随着科技力量和工艺技术的发展,制造业及用户厂家对铸件质量,尤其是铸件及砂型表面质量的需求逐渐提高。基于增材制造技术的激光烧结技术由于加工速度快且成型精度高,在铸造行业得到了国内外研究机构的广泛认同,但是由于粉末的尺度、激光光斑直径以及离散化分层的影响,砂型表面质量仍存在提升的空间。为获得具备良好表面质量的砂型,适当地选用铸型涂料是一条有效的途径。利用增材制造技术制备试验砂型,将机器人与砂型涂料涂覆相结合,利用影像测量设备对涂覆后砂型表面进行观测,对影响涂层表面质量的因素进行研究。通过多指标正交试验分析方法,获得了在满足表面粗糙度需求的前提下,涂层厚度尽可能小的最优因素组合,为激光增材制造砂型后处理表面质量提升提供了工艺参考。

With the development of scientific strength and process technology, the demand for casting quality, especially surface quality of casting and sand, has gradually increased in manufacturing and user manufacturers. The laser sintering technology on the basis of additive manufacturing technology has high processing speed and high molding precision. The application in the foundry industry has been widely recognized by domestic and foreign research institutions, but due to influence of the powder size, the diameter of the laser spot and the discrete layering, there is still room for improvement in the sand surface quality. In order to obtain the sand mold with good surface quality, the proper selection of the mold coating is an effective way. The test sand mold has been prepared by the additive manufacturing technology and the robot has been combined with the sand coating. The coated sand mold surface has been observed by the image measuring equipment to study the factors affecting the surface quality of the coating. Through the multi-index orthogonal experimental analysis method, the optimal factor combination of the smallest coating thickness has been obtained under the premise of satisfying the surface roughness requirement, which provides a process reference for the surface quality improvement of sand mold by laser additive manufacturing.