温度辅助激光冲击强化对GH4169合金力学性能的影响

Effect of temperature-assisted laser shock peening on mechanical properties of GH4169 alloy

利用波长为1064 nm、脉宽为14 ns、单脉冲能量为5 J的Nd:YAG纳秒脉冲激光器对GH4169合金试件进行了常温激光冲击强化处理和温度辅助激光冲击强化处理;采用X射线衍射仪和HV-1000显微硬度计测量了强化处理前后试件的表面残余应力与表面显微硬度。实验结果表明:经激光冲击强化与温度辅助激光冲击强化处理后,试件表面引入了一定数值的残余压应力,同时表面显微硬度得到提高;但在残余压应力和显微硬度数值方面,经温度辅助激光冲击强化处理的试件均比常温激光冲击强化处理的试件要大,且随着辅助温度的增加,试件的表面残余压应力和表面显微硬度值均呈增加趋势。因此,在一定的温度范围内,采取温度辅助激光冲击强化的方式对GH4169合金进行处理,可以获得比常温激光冲击强化处理更好的强化效果,同时适当提高强化温度,在一定程度上可以进一步提高GH4169合金的强化效果。

The treatment of room temperature laser shock peening and temperature-assisted laser shock peening for GH4169 alloy samples were carried out on using Nd:YAG laser system with the wavelength of 1064 nm,pulse width of 14 ns and pulse energy of 5 J.Surface residual stress and micro-hardness before and after laser peening were tested by X-ray diffraction machine and HV-1000 micro-hardness tester,respectively.The experimental results show that after the treatment of laser shock peening and temperature-assisted laser shock peening,a certain amount of residual compressive stress is introduced on the surface of samples.Meanwhile,the micro-hardness of samples is improved.However,in terms of the values of residual compressive stress and micro-hardness,the samples shock processed by temperature-assisted laser shock peening are lager than the sample shock processed by room temperatnre laser shock peening.And with the increase of the assisted temperature,both the surface residual compressive stress and surface micro-hardness of the GH4169 alloy samples show an increasing trend.So,in a certain temperature range,the GH4169 alloy processed by the temperature-assisted laser shock peening can get a better strengthen effect than that by the laser shock peening at room temperature,and increasing the assisted temperature appropriately can improve the strengthen effect of GH4169 alloy.