摘要
高性能金属构件的激光增材制造可以实现复杂零件的“近净成形”,是近年来航空、航天、船舶海洋等现代重大装备制造业的研究热点。由于增材制造过程中材料的熔凝行为受原材料组分和制备工艺的影响,一旦材料或成型工艺选择不合理,成型件会不可避免地出现缺陷,影响构件性能。因此,对金属构件激光增材制造中的缺陷产生机理及控制机制进行研究很有必要。总结了近年来金属构件激光增材制造缺陷的控制方法,归纳了缺陷的种类,对制造过程中的三种典型缺陷——裂纹、孔隙和夹杂的产生机制进行了分析,并根据其产生机理针对性地提出了相应的控制机制,展望了金属构件激光增材制造缺陷控制方法的未来发展方向。
Significance Metallic components have been widely used in aviation,aerospace,marine and other industrial departments for their excellent properties.Over the past decades,metallic components are developing toward to high-performance and multi-function but with low production cost,which pushes new manufacturing techniques to be used.Laser additive manufacture(LAM)is one of the new additive manufacturing techniques,which is widely used to manufacture near-net-shaped metal parts layer-by-layer by melting metal powders using a laser beam.Now,it is also widely used to manufacture large and critical high performance metallic components with advantages in reducing material waste,production time and cost.In the LAM process,the components undergo periodic and unstable thermal cycling,which influences the microstructure and internal stress.More importantly,the inappropriate selection of process parameters leads to the appearance of defects with degradation of mechanical property.For example,if there exists porosity in the material powder,the pores occur during LAM and the liquid condensation speed is faster than the gas escape speed.If the selected laser power is too low,the powder is hardly fully molten and the unfused pores and inclusions are generated.Therefore,the extensive researches worldwide focus on studying the generation mechanism of defects in the LAM process.In Deng’s research,the 15%(volume fraction)SiC ceramic reinforced steel(MS)metal matrix composites were prepared by selective laser melting(SLM).Facing the compatibility and cracking problems raised between SiC and metal matrix,great efforts on the suppression of defects during the SLM process are taken from various aspects,including laser melting,substrate preheating,and design of support and build directions.Substrate preheating can be used for the significant suppression of cracks.Tillmann et al.treated the IN718 component with the HIP method and the density of components was increased to 99.985%--99.989% within a certain range.However,most of the resea
作者
姚讯杰
王佳玮
杨雁程
张馨月
程序
张述泉
Yao Xunjie;Wang Jiawei;Yang Yancheng;Zhang Xinyue;Cheng Xu;Zhang Shuquan(School of Material Science and Engineering,Beihang University,Beijing 100191,China;Rersearch Institute for Frontier Science,Beihang University,Beijing 100191,China;Beijing Yuding Additive Manufacturing Research Institute Co.,Ltd.,Beijing 100096,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2022年第14期278-288,共11页
Chinese Journal of Lasers
基金
广东省基础与应用基础研究重大项目(2020B0301030001)。
关键词
激光技术
材料
激光增材制造
金属构件
缺陷
控制机制
laser technique
materials
laser additive manufacturing
metallic components
defect
control mechanism