Investigation on the Cracking Mechanism of Melt Growth Alumina/Aluminum Titanate Ceramics Prepared by Laser Directed Energy Deposition  

作　　者：Yunfei Huang Dongjiang Wu Chengxin Li Weijie Lv Guangyi Ma Cong Zhou Fangyong Niu 

机构地区：[1]State Key Laboratory of High-performance Precision Manufacturing,Dalian University of Technology,Dalian,116024,China [2]Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China

出　　处：《Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers)》2023年第4期23-32,共10页中国机械工程学报（增材制造前沿）（英文）

基　　金：supported by National Natural Science Founda-tion of China(Grant.Nos.51805070,51790172,52175291);Funda-mental Research Funds for the Central Universities of China(Grant.Nos.DUT22YG210,DUT22LAB117);Science Center for Gas Turbine Project of China(Grant.No.P2022-B-IV-012-001);Shenzhen Sci-ence and Technology Innovation Commission of China(Grant.No.JCYJ20210324115413036).

摘　　要：Oxide melt growth ceramics(OMGCs)exhibit excellent performance and microstructure stability near their melt-ing point and are expected to become a new structural material for long-term stable service in extremely high-temperature water-oxygen environments.Owing to its unique advantages of high efficiency,flexible manufac-turing,and near-net shaping,laser directed energy deposition(LDED)has become a promising technology for the rapid preparation of high-performance OMGCs.However,owing to the limited understanding of the crack-ing mechanism,the severe cracking problem that hinders OMGCs-LDED towards engineering applications has not been resolved.Alumina/aluminum titanate(Al_(2)O_(3)/Al_(x)Ti_(y)O_(z),A/AT)ceramics are prepared using an LDED system and their cracking characteristics are investigated.Subsequently,numerical simulations are conducted to reveal the dominant factors and influencing mechanisms of the cracking behavior.The results demonstrate that the cracking nucleation process is mainly controlled by solidification defects,whereas the cracking propagation process is determined primarily by both the microstructure and stress level.This study provides a theoretical basis for the development of appropriate cracking suppression methods for OMGCs-LDED.

关 键 词：Additive manufacturing Laser directed energy deposition Composite ceramics Alumina/aluminum titanate Cracking mechanism 

分 类 号：TQ174[化学工程—陶瓷工业]