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对FGH97粉末高温合金进行激光冲击强化和喷丸强化,利用X射线应力分析仪测定强化层的残余应力,测定650℃下旋转弯曲疲劳性能,利用SEM观察分析疲劳断口特征。结果表明,2种表面强化方法都可以提高FGH97粉末高温合金的疲劳性能,但激光冲击强化比喷丸强化具有更深的残余压应力层和较好的表面粗糙度,且残余应力在高温疲劳载荷下的松弛较小,因此具有更好的强化效果;与未表面强化的试样相比,喷丸强化和激光冲击强化试样的疲劳裂纹源都出现在亚表面,而未强化试样的疲劳裂纹源则出现在表面。
The FGH97 powder superalloy was subjected to laser shock peening and shot peening. The residual stress of the strengthened layer was measured by X-ray stress analyzer. The bending fatigue properties at 650 ℃ were measured. The fatigue fracture characteristics were analyzed by SEM. The results show that both of the surface strengthening methods can improve the fatigue properties of FGH97 powder superalloys. However, laser shock peening has deeper residual compressive stress layer and better surface roughness than shot peening, and the residual stress under high temperature fatigue load Less slack, so it has a better strengthening effect; compared with the non-surface-enhanced specimens, the shot-peening and laser-induced fatigue cracked specimens appear on the subsurface without fatigue cracks The source appears on the surface.