90W-7Ni-3Fe激光选区熔化热行为及试验分析

激光选区熔化是一种成形难加工金属的方法，文中以90W-7Ni-3Fe为研究对象，分别考虑材料在粉末和实体状态下的物性参数，建立温度场有限元模型，模拟成形过程中的温度场，研究了不同工艺参数下的熔池尺寸、温度梯度、冷却速率变化等. 温度场分析表明，熔道中心温度超过了钨的熔点，粉末充分熔化，而熔道搭接处温度仅超过镍铁熔点，钨颗粒并未熔化，因此在相邻道之间区域是以液相烧结方式形成. 同时，设计了相应参数的工艺试验，发现增大能量输入，可以使液相填充更加充分，成形件致密度提高.

90W-7Ni-3Fe selective laser melting heat behavior analysis and experimental research

Selective laser melting is a method for forming difficult-to-machine metals. In this paper, 90W-7Ni-3Fe is taken as the research object, and the physical properties parameters of the material in the powder and solid state are considered respectively, and the finite element model of the temperature field is established to simulate the forming process. Temperature field, the melt pool size, temperature gradient, cooling rate changes under different process parameters were studied. The analysis of the temperature field shows that the temperature of the center of the melt channel exceeds the melting point of tungsten, and the powder is fully melted, while the temperature of the overlap of the melt channel only exceeds the melting point of nickel iron, and the tungsten particles are not melted. Formed by sintering. At the same time, process experiments with corresponding parameters were designed, and it was found that increasing the energy input can make the liquid phase filling more sufficient and the density of the shaped parts increased.