文献类型：期刊文献

中文题名：激光强化渗氮过程的数值模型及分析

英文题名：Numerical Model and Simulation for Laser-Intensified Surface Nitriding

作者：曹丽琴[1];轩福贞[1];王正东[1];涂善东[1]

机构：[1]华东理工大学机械与动力工程学院,上海200237

年份：2008

卷号：35

期号：8

起止页码：1255

中文期刊名：中国激光

外文期刊名：Chinese Journal of Lasers

收录：CSTPCD;;EI(收录号：20083811559084);Scopus;北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；

基金：上海市重点学科建设项目(B503)资助课题

语种：中文

中文关键词：激光技术;激光氮化;温度场;氮扩散;数值模拟

外文关键词：laser technique laser nitriding temperature field nitrogen diffusion numerical simulation

摘要：根据傅里叶传热方程和修正的菲克定律,建立了瞬态激光氮化温度场和浓度场的耦合模型,考虑移动热源形成的温度梯度对氮扩散的影响.有限元模拟分析了激光氮化工艺过程温度场和浓度场的分布规律.结果表明,严格控制氮化温度,反复调整热流密度和扫描速度,得到各自的临界值,可作为工艺可调参考范围.修正的扩散方程考虑了温度梯度对氮扩散的影响,较真实地反映了激光热作用下氮的扩散过程,得到了整个氮化层的厚度.区别于常规氮化工艺,激光氮化扩散的主动力是高的表面温度梯度,浓度梯度的影响减弱.增大热流量和降低扫描速度,都将使氮化深度增加,但参数的选择太高或太低,均得不到高质量的氮化结果.
Finite-element models of the temperature coupled the concentration of kinetics during laser nitriding were considered. Coupled calculations of the non-steady state Fourier heat conduction equation and the Fick law of modified diffusion equation showed the variation and distribution of nitrogen concentration and the temperature in the metal surface layer. The results indicate that, the temperature of laser nitriding can be controlled exactly to gain the critical values of the heat flux and scanning rate respectively by trial-and-error, as the applicable reference range of progress. The modified diffusion equation, which considered the temperature gradient and thus showed a fairly good explanation of the N diffusion using the high-energy laser to fill the heat. The whole thickness of nitrides layer can be obtained through the simulation. The dynamic of laser nitriding is the high surface temperature gradient, which differs from the conventional process. The nitrogen concentration gradient is never considered as the main influence element. The thickness of nitrides increases when heat flux is increased or the scanning rate is reduced. Simulation indicates that good results can be obtained when these parameters are chosen properly.