【作者】 胡涛；

【导师】 杨继昌； 花银群；

【作者基本信息】 江苏大学 ， 机械制造及其自动化， 2002， 硕士

【摘要】 在激光相变硬化中,月牙形硬化层的最大深度与激光束作用下零件内的温度场分布有着十分密切的关系。作者分析了近年来国内外学者在激光相变硬化温度场分布与相变硬化层预测方面所作的研究成果,提出在激光作用下零件内沿激光扫描方向截面内的三维温度场分布,建立了一个三维非稳态移动热传导物理模型;并针对均强圆形光束模型,经适当的数学处理,得到了能够完整地描述激光扫描作用下零件沿激光扫描截面内三维非稳态移动热源温度场分布的近似解析解。在上述研究成果的基础上,作者依据优化设计理论,对给定的硬化层深度,应用世界上通用的ANSYS5.5有限元分析软件,模拟激光相变硬化温度场的形成以确定最优的激光硬化工艺参数,这是作者在激光参数的理论选择研究方面所作的有益尝试。实验研究表明,相变硬化层的理论预测具有较好的可靠性和准确性,它对激光热处理的实际应用具有重要的指导意义。更多还原

【Abstract】 For Laser Transformation Hardening (LTH) ,the maximal crescent-shaped sizes of the hardening case are closely to the temperature field induced by laser scanning on the surface of the part. First, Laser Transformation Hardening concept and its features are induced in brief. Second, the researches and the latest achievements on temperature distribution and prediction of hardened case made by many researchers are presented. The author makes an opinion that there is a feature of three-dimensional distribution in temperature field induced by laser scanning. Then a physical model with three dimensions motive transient conduction is set up. Finally, an analytical formula of three dimensions motive transient temperature distribution served for circular beam mode with homogenous power density is presented through suitable mathematics processing. Based on the optimization theory in the case of a given laser hardened case, the author simulates the temperature field of Laser Transformation Hardening and optimizes the laser hardening parameters with the ANSYS5.5 finite cell software which is current and high-efficient in the world nowadays. It is the author’s useful attempt in the optimization of laser hardening parameters. It is proved that the research methods are reasonable and the theoretical prediction of the hardened case is fairly reliable and accurate.更多还原