为研究飞秒脉冲激光冲击强化中等离子体压力时空演化规律,利用考虑电子态密度(DOS)效应的模型计算了电子热容和电声耦合系数随电子温度的演化规律,并与采用QEOS(quotidian equation of state)模型计算结果进行了对比;提出DOS飞秒脉冲激...为研究飞秒脉冲激光冲击强化中等离子体压力时空演化规律,利用考虑电子态密度(DOS)效应的模型计算了电子热容和电声耦合系数随电子温度的演化规律,并与采用QEOS(quotidian equation of state)模型计算结果进行了对比;提出DOS飞秒脉冲激光冲击强化模型,计算得到电子温度、晶格温度、等离子体羽位置时间演化规律和等离子体压力时空演化规律,并与QEOS飞秒脉冲激光冲击强化模型结果进行了对比。结果表明:DOS飞秒脉冲激光冲击强化模型计算得到的等离子体羽位置随时间的演化规律与实验结果吻合程度更好;增加激光能量或功率密度、考虑电子DOS效应会增加电子、晶格温度和等离子体压力。展开更多
The effects of nanosecond laser shock peening without coating(LSPwC)and nanosecond stacked femtosecond laser shock peening compound strengthening(LSP-CS)on the surface integrity and fretting fatigue lifetime at 500℃o...The effects of nanosecond laser shock peening without coating(LSPwC)and nanosecond stacked femtosecond laser shock peening compound strengthening(LSP-CS)on the surface integrity and fretting fatigue lifetime at 500℃of GH 4169 dovetail component were investigated.The results show that LSP treatment does not significantly lead to changes in the grain size of GH 4169 alloy,but it introduces a large number of dislocations,resulting in the formation of a plastic deformation layer and residual compressive stress layer.The surface microhardness increased by 20.5%and 28.6%after being treated by LSPwC and LSP-CS,respectively.The surface residual compressive stresses were(-306.5±42.5)MPa and(-404.3±34.7)MPa,respectively;The depth of both the hardening layer and the residual compressive stress layer is 400μm,and along the cross-section with 0-100μm region after LSP-CS treatment has higher hardness and greater residual compressive stress.The fretting fatigue lifetime of the GH 4169 dovetail component at 500℃was increased by 346.8%and 494.9%,which is the result of the combined effects of the hardening layer and the residual stress layer.The LSP-CS treatment can effectively make up for the disadvantage of the LSPwC treatment,and further enhance the fretting fatigue lifetime of the GH 4169 dovetail component at high temperature.展开更多
文摘为研究飞秒脉冲激光冲击强化中等离子体压力时空演化规律,利用考虑电子态密度(DOS)效应的模型计算了电子热容和电声耦合系数随电子温度的演化规律,并与采用QEOS(quotidian equation of state)模型计算结果进行了对比;提出DOS飞秒脉冲激光冲击强化模型,计算得到电子温度、晶格温度、等离子体羽位置时间演化规律和等离子体压力时空演化规律,并与QEOS飞秒脉冲激光冲击强化模型结果进行了对比。结果表明:DOS飞秒脉冲激光冲击强化模型计算得到的等离子体羽位置随时间的演化规律与实验结果吻合程度更好;增加激光能量或功率密度、考虑电子DOS效应会增加电子、晶格温度和等离子体压力。
基金Project(2022YFB3401900)supported by the the National Key R&D of ChinaProject(2025YFHZ0163)supported by the the Science and Technology Projects in Sichuan Province,ChinaProject(2682024GF004)supported by Fundamental Research Funds for the Centeral University,China。
文摘The effects of nanosecond laser shock peening without coating(LSPwC)and nanosecond stacked femtosecond laser shock peening compound strengthening(LSP-CS)on the surface integrity and fretting fatigue lifetime at 500℃of GH 4169 dovetail component were investigated.The results show that LSP treatment does not significantly lead to changes in the grain size of GH 4169 alloy,but it introduces a large number of dislocations,resulting in the formation of a plastic deformation layer and residual compressive stress layer.The surface microhardness increased by 20.5%and 28.6%after being treated by LSPwC and LSP-CS,respectively.The surface residual compressive stresses were(-306.5±42.5)MPa and(-404.3±34.7)MPa,respectively;The depth of both the hardening layer and the residual compressive stress layer is 400μm,and along the cross-section with 0-100μm region after LSP-CS treatment has higher hardness and greater residual compressive stress.The fretting fatigue lifetime of the GH 4169 dovetail component at 500℃was increased by 346.8%and 494.9%,which is the result of the combined effects of the hardening layer and the residual stress layer.The LSP-CS treatment can effectively make up for the disadvantage of the LSPwC treatment,and further enhance the fretting fatigue lifetime of the GH 4169 dovetail component at high temperature.
