激光能量输入对直接激光沉积莫来石陶瓷组织性能的影响  

Effect of Laser Energy Input on Microstructure and Properties of Direct Laser Deposited Mullite Ceramics

作　　者：赵大可 吴东江[1] 牛方勇[1] 马广义[1] Zhao Dake;Wu Dongjiang;Niu Fangyong;Ma Guangyi(Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学精密与特种加工教育部重点实验室,辽宁大连116024

出　　处：《稀有金属材料与工程》2021年第3期1007-1015,共9页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51805070,51790172);中央高校基本科研业务项目(DUT19RC(3)060);辽宁省自然科学基金指导计划项目(2019-ZD-0010)。

摘　　要：研究了激光能量密度对直接激光沉积熔体自生莫来石陶瓷孔隙/密度、微观组织和力学性能的影响。结果表明,较低激光能量密度(15 J/mm^(2))所制备的陶瓷样件边缘分布有尺寸较大的气孔,使得样件整体孔隙率较高,且表面粘粉严重,这与成形扫描速度大和硅酸盐熔体粘度高有关。而较高激光能量密度(90 J/mm^(2))虽然可以获得表面光滑、莫来石晶粒尺寸较小的陶瓷样件,但由于单位时间内输入熔池能量高,粉末蒸发产生的气孔来不及逃逸出熔池,使得样件心部形成较大的气孔,影响样件的力学性能。在激光能量密度为45J/mm^(2)时,获得了表面相对光洁、孔隙率较低和力学性能较好的莫来石陶瓷样件。本研究结果为直接激光沉积增材制造高性能陶瓷过程中合理选定工艺条件提供了理论指导及技术支撑。The effects of laser energy density on the porosity/density,microstructure,and mechanical properties of direct laser deposited melt growth mullite ceramics were investigated.The results show that the mullite ceramic samples prepared with lower laser energy density(15 J/mm^(2))have large pores distributed on the edges,making the porosity of the specimen higher.The sample surface has serious sticky powder,which is related to the high scanning speed and the high viscosity of the silicate melt.The ceramic samples with a smooth surface and smaller mullite grain size can be prepared by higher laser energy density(15 J/mm^(2)).However,due to the high energy input into the molten pool per unit time,the pores generated by the evaporation of the powder are too late to escape from the molten pool,resulting in larger pores in the core of the sample,deteriorating the mechanical properties of the samples.The mullite ceramic samples with a relatively smooth surface,low porosity,and high mechanical properties can be obtained when the laser energy density is 45 J/mm^(2).The results of this study can provide theoretical guidance and technical support for the rational selection of process conditions in the process of manufacturing high-performance ceramics with directed laser additive manufacturing.

关 键 词：增材制造 陶瓷 激光能量密度 孔隙 力学性能 

分 类 号：TQ174.758.11[化学工程—陶瓷工业]