基于凝聚介质模型的矩形均匀激光诱导冲击强化研究

The Research on Rectangular Uniform Laser Induced Shock Strengthening Based on Condensed Medium Model

基于凝聚介质模型分析了均匀矩形激光脉冲诱导冲击压强峰值,以及其在金属材料中产生的残余压应力分布。利用稠密气体状态方程和冲击波基本关系式推导得到矩形均匀激光冲击产生的塑性影响深度L_(p)与激光峰值光强I_(p)的2/3次方存在正比关系。对LY2铝合金材料进行矩形均匀激光冲击强化并测试其残余应力深度及振动疲劳寿命,残余应力深度超过1.2 mm,与未处理试件相比较,振动疲劳寿命平均提升了4.5倍。利用矩形均匀激光冲击强化可有效预防金属材料的振动疲劳失效,提高金属材料的振动疲劳寿命,延长金属材料的服役时间。

The shock pressure induced by rectangular uniform laser pulse and the distribution of residual compressive stresses in metal materials were analyzed based on the condensed matter model.The plastic influence depth L_(p) produced by rectangular uniform laser shock was derived from the basic shock wave relations and the stiffened gas equation of state,which was related to the two-thirds power of laser peak intensity I_(p).The LY2 aluminum alloy was shocked by rectangular uniform laser pulse and the residual stress and vibration fatigue life were measured.The residual stress depth was more than 1.2 mm.Compared with the untreated specimens,the average vibration fatigue life was increased by 4.5 times.Therefore,using the rectangular uniform laser peening technique can effectively prevent the vibration fatigue failure of metal materials,improve the vibration fatigue life,and prolong the service time of metal materials.