齿轮曲面激光熔覆应力场数值模拟

Numerical simulation of gear laser cladding

激光熔覆的温度场及应力场分析基本上是基于平面基体上熔覆的分析。实际应用中熔覆可能会在任意曲面上进行,曲面与平面不同之处在于曲面的曲率会引起激光功率分布不均。通过分析齿轮轮齿熔覆层形貌、讨论影响激光实际应用功率的因素(包括粉末对激光的遮蔽、激光入射角度的变化和齿轮齿廓形状),并在考虑熔覆过程中相变问题的基础上,利用有限元软件模拟了不同熔覆材料与基体材料配对情况下齿轮表面熔覆的应力场。结果表明:采用适当的材料匹配及将基体预热到一定温度,可以减少甚至避免齿轮熔覆层裂纹的产生。

Most of the temperature and stress fields simulations in laser cladding were based on flat surface, while actually cladding may occur on any curved surface. The difference between cladding on flat surface and curved surface is that the latter will result in uneven distribution of laser power. Experiments of laser cladding have been done on different material gears under various technical conditions, and crackles have been observed by SEM. Some factors that affect laser power actually, such as laser shielding, the incident angle of laser and curved surface of gear are all considered. Based the analysis of the shape of layer after cladding and the phase transformaion during cladding, stress fields of gear surface laser cladding have been simulated by ANSYS in this article. The results indicate that appropriate material matching and base preheating can decrease the likelihood of crackles, even eliminate it.