NiTi形状记忆合金激光选区熔化成形温度场的数值模拟与试验研究
Numerical Simulation and Experimental Study of Temperature Field in Laser Selective Melting of NiTi Shape Memory Alloy
贺庆 1闫俊霞 2区炳显 3孟祥伟1
作者信息
- 1. 江南大学机械工程学院,江苏无锡 214122
- 2. 江南大学机械工程学院,江苏无锡 214122;江苏省食品先进制造装备技术重点实验室,江苏无锡 214122
- 3. 江南大学机械工程学院,江苏无锡 214122;江苏省特种设备安全监督检验研究院,国家石墨烯产品质量监督检验中心(江苏),江苏无锡 214174
- 折叠
摘要
激光选区熔化(selective laser melting,SLM)成形过程涉及复杂的热量变化与能量传输,使熔池的温度分布与形貌结构发生变化,从而导致成形件性能受到影响.通过有限元ANSYS软件建立三维瞬态模型,研究激光功率与扫描速度对SLM成形NiTi单层多道热行为的影响.结果表明,由于扫描过的区域会对未扫描区域预热,导致前后两条扫描轨迹的峰值温度存在差异,且熔池的峰值温度与尺寸会随激光功率的增大或扫描速度的减小而增大;当激光沿不同路径移动时,激光功率相较于扫描速度对熔池的温度梯度影响更大;结合试验可知,随着功率与扫描速度的增大,显微组织更加均匀,但功率过小或者扫描速度过大,会使NiTi合金成形件组织内产生孔隙、杂质相以及裂纹等缺陷.
Abstract
The forming process of Selective Laser Melting(SLM)involves complex heat change and energy transfer,which changes the temperature distribution and morphology structure of the molten pool,thus affecting the performance of the form-ing parts.In this paper,a three-dimensional transient model was established by finite element software ANSYS to study the effects of laser power and scanning speed on the thermal behavior of NiTi monolayer formed by SLM.The results show that the scanned area will preheat the unscanned area,leading to the difference in peak temperature between the two scanning tracks,and the peak temperature and size of the molten pool will increase with the increase of laser power or the decrease of scanning speed.When the laser moves along different paths,the laser power has a greater impact on the temperature gradient of the molten pool than the scanning speed.Combined with the experiments,it can be seen that as power and scanning speed elevate,the microstructure of the NiTi alloy formed parts becomes more uniform.However,excessively low power or high scanning speeds can induce pores,impurities,and cracks within the NiTi alloy component's microstructure.
关键词
激光选区熔化/NiTi形状记忆合金/数值模拟/工艺参数/温度场Key words
laser selective melting/NiTi shape memory alloy/numerical simulation/process parameters/temperature field引用本文复制引用
基金项目
江苏省市场监督管理局科技项目(KJ21125038)
江苏省特种设备安全监督检验研究院科技项目(KJY2020038)
出版年
2024
NETL
NSTL
万方数据