热处理对激光选区熔化成型CoCrMo合金性能影响研究

为了获得性能优良的医学植入体，需对热处理后的激光选区熔化（SLM）成型零件的性能进行研究。应用拉伸试验机和冲击试验机分别对成型件进行拉伸和冲击实验；显微硬度计测试CoCrMo合金在不同条件下的硬度差别；通过金相显微镜和扫描电子显微镜（SEM）对其表面形貌进行观察，研究其断裂机理。结果表明:未处理的SLM成型件具有较高的抗拉强度，1 200℃退火炉冷条件下具有较高的延伸率；硬度随热处理温度的升高逐渐降低；冲击功与热处理温度之间呈U型关系；随热处理温度的升高，成型件晶粒逐渐变大，内应力逐渐变低；1 200℃退火条件下的断裂机理为韧性断裂，这为激光选区熔化成型CoCrMo合金在医学植入体方面的应用提供了依据。

Influence of heat treatment on the performance of selective laser melting manufacturing CoCrMo alloy

In order to acquire medical implants with excellent performance, research needs to be conducted on the performance of selective laser manufacturing parts after heat treatment. Tensile testing machine and impact testing machine were adopted to carry out tensile and impact experiments respectively to the manufacturing parts. Metalloscope and SEM were used to observe the surface topography and study its fracture mechanism. The results show that the untreated manufacturing parts built by SLM have high strength of extension. SLM manufacturing CoCrMo alloy has higher ductility under cold condition in 1 200℃ annealing furnace. The hardness decreases with the temperature increase of heat treatment. There is a U-shaped relationship between the impact energy and heat treatment temperature. With the increase of heat treatment temperature, crystal grain of SLM manufacturing parts become bigger gradually and the internal stress reduces. The fracture mechanism under the condition of 1 200℃ annealing is ductile fracture, which provides the basis for the application of SLM CoCrMo alloy in the medical implants.