扫描电子束铝合金表面处理应力场仿真与试验验证

Simulation and Experimental Research of Stress Field in the Process of Aluminum Alloy Surface Modifying by Electron Beam

研究扫描电子束铝合金表面处理应力场的分布规律,对了解残余应力的形成机理具有十分重要的理论及实际意义。在热弹塑性理论的基础上建立电子束表面处理应力场的有限元模型,分析高温热力学参数对电子束表面处理应力场的影响;通过仿真与试验验证相结合的方法确定材料的高温热力学参数,得到铝合金电子束表面扫描后的应力分布规律。随着弹性模量和切变模量的增加,ADC12铝合金材料表面的变形量和最大应力均成非线性增加。经电子束表面处理后试样表面扫描带附近为拉应力,而在其他位置为压应力;最大拉应力出现在扫描带的内侧边缘处,外侧边缘次之,而扫描带中间的拉应力最小;最大表面应力为127.6 MPa,变形量为1.8 mm。

It has great theoretical and practical significance in researching the scanning electron beam surface treatment stress distribution for understanding the formation mechanism of residual stress.Based on the thermal elastoplastic theory,a finite element model of electron beam surface treatment stress field is established to analysis the influence of high temperature thermodynamics parameters on the stress distribution of aluminum after electron beam surface treatment.Through the method that simulation combined with experimental verification,the material thermodynamic parameters of the high temperature is determined and the distributions of the stresses of the aluminum alloy surface after scanned is obtained.ADC12 aluminum alloy area deformation and the maximum stress increased nonlinearly with elastic and shear modulus.Tensile stress centralize nearby scanning band of sampling surface after surface treated,compressive stress centralized at the other location.The maximum tensile stress is present in the inner side of scanning band,the lateral border is lower than that,the value in the middle of scanning band is the lowest.The maximum surface stress is 127.6 MPa,deformation comes to 1.8 mm.