金属光固化3D打印研究现状

Review of the stereolithographic 3D printing of metals

通过对金属光固化3D打印的研究结果和工艺流程进行总结,划分了四种主要的实现途径,即固化烧结法、固化镀膜法、混合固化法和固化模具法,其中固化烧结法是制备金属零件的主要方法,固化镀膜法常用于制备精密电磁设备元件,而混合固化法通常直接固化浆料而无需经过烧结使零件一步成型;归纳了金属光固化3D打印所使用的光敏树脂成分和所制备零件的性能;指出了该技术目前发展还存在浆料中金属与聚合物性质差异、工艺参数研究不足、光敏树脂配方较少等亟待解决的关键科学问题;从研究工艺参数对零件性能的影响、开发新型光敏树脂配方和发明更适用于金属光固化3D打印的设备方面展望了其未来的发展方向.

Stereolithographic three-dimensional(3D)printing of metals is a new additive manufacturing technology.The metal parts prepared by this technology have the characteristics of complex shape and precise structure,and no post-processing is required.It is an advanced manufacturing technology that has enormous potential in fabricating complex parts owing to the considerable progress of stereolithography,digital light processing,liquid crystal displays,continuous liquid interface production,and two-photon polymerization in recent years.This paper summarizes the current research progress on stereolithographic 3D printing of metals and defines four major methodologies,namely,curing sintering,curing coating,mixed curing,and curing mold.Of these,the curing sintering method is the primary technique to prepare metal parts by mixing metal powder with photosensitive resin and forming parts through degreasing and sintering at high temperatures.In curing coating,a metal film is coated on the surface of a solidified resin matrix,which is often used to prepare precision electromagnetic equipment.The mixed curing process is used to directly cure metal slurry without sintering to complete the one-step formation of parts.The curing mold technique is used to realize the multistep formation of parts by using the resin matrix or the ceramic matrix as the mold,followed by subsequent treatments such as casting.In this review,the composition of metal slurry and the resulting properties of the stereolithographic 3D printed metal parts are summarized.Key scientific questions on the property difference between metals and polymer in the slurry,immature processing parameters,lack of reliable compositions for photosensitive resin are still unresolved.The direction of future development is forecasted by studying on the influence of process parameters on the performance of parts,on the new formulas of photosensitive resin,and on more suitable equipment for the stereolithographic 3D printing of metals.