选择性激光熔化成形瞬态温度场数值模拟  

Numerical Simulation of Transient Temperature Field in Selective Laser Melting

作　　者：李佳桂[1] 史玉升[1] 鲁中良[1] 黄树槐[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,武汉430074

出　　处：《中国机械工程》2008年第20期2492-2495,共4页China Mechanical Engineering

基　　金：湖北省自然科学基金创新群体项目(2004ABC001);中南大学粉末冶金国家重点实验室开放基金资助项目(200506123102A)

摘　　要：为揭示选择性激光熔化成形的机理,初步建立了其熔化过程的传热理论模型;考虑温度变化对材料热物性参数的影响,利用ANSYS参数化设计语言(APDL)建立了有限元数值模型并进行了温度场求解。计算结果显示:熔化成形过程中温度场等值线呈椭圆状,已凝固部分在光斑再次扫描至邻近部位和上层粉末时由于热传导作用而发生重熔;熔池的尺寸大小随吸收能量的增加而逐渐增大,由初始宽约0.2mm增至0.25mm左右;温度场分布均匀、温度梯度小可减小零件的翘曲变形;基板温度随时间的推移而逐渐升高。In order to reveal mechanism of selective laser melting process, the well--known heat conduction equation was used to describe the phenomena,and thermo physical parameters of materials were considered to be temperature--dependent. The moving laser beam was simulated by using the ANSYS parametric design language （APDL） to provide the heat boundary condition at different positions and different time, and then calculated temperature distribution. The result shows that temperature distribution is elliptic. Sweep line will be re--melted when laser beam moves beside of them again. The molten pool which can be seen is wider at the end than that of the front of the heat accumulation,which shows good agreement with the actual situation. Warpage will be reduced when temperature distribution is uniform and temperature gradient is small. The substrate＇s temperature will rise with the time increasing.

关 键 词：选择性激光熔化 传热理论模型 有限元模型 温度场 

分 类 号：TG14[一般工业技术—材料科学与工程] TN2[金属学及工艺—金属材料]