AlSi10Mg粉末激光选区熔化温度场的数值模拟

Numerical simulation of selective laser melting temperature field of AlSi10Mg powder

使用有限元软件Ansys模拟Al Si10Mg激光选区熔化过程的温度场。考虑材料的热物性参数及激光能量吸收率随温度变化的特性,将激光热源视为三维高斯体热源,实现在粉床上的移动加载,实时进行材料由粉末态转化为实体态的单元属性转变,研究激光功率、扫描速度及扫描间距对粉床热行为的影响。结果表明:熔池最高温度、熔池尺寸及冷却速度随激光功率的增大逐渐增大;熔池最高温度与熔池尺寸随扫描速度的增大逐渐减小,熔池冷却速度随扫描速度的增大逐渐增大;扫描间距对熔池的最高温度、冷却速度及熔池尺寸影响不大,但扫描间距过大容易形成孔洞缺陷。

Finite element software ANSYS is used to simulate the temperature field of the selective laser melting of Al Si10 Mg powder.Considering the characteristics of the thermophysical property of the material and the laser energy absorption rate varying with temperature, the laser heat source is regarded as a three-dimensional Gaussian heat source for moving loading on the powder bed.During the loading process of the heat source,the conversion of the properties of the material from the powder state to the solid state is realized in real time. The effects of the laser power,scanning speed and scanning interval on the thermal behavior of the powder bed are studied. The results show that the maximum temperature,size and cooling rate of the molten pool increase as the laser power increases. The maximum temperature and size of the molten pool decrease as the scanning speed increases,however,the cooling rate of the molten pool increases as the scanning speed increases. The scanning interval has little effect on the maximum temperature,size and cooling rate of the molten pool,but too large scanning interval is likely to cause hole defects.