水射流喷丸强化的试验研究

为获得水射流喷丸强化对材料表面力学特性和疲劳寿命的影响规律,选择喷丸压力、移动速度和靶距为影响因素,应用水射流对2A11铝合金和45钢进行喷丸试验;采用显微硬度计和X射线应力分析仪分别测定喷丸表面显微硬度和表面残余应力,利用扫描电子显微镜进行疲劳断口形貌观察,应用能谱仪进行内部疲劳源区夹杂物成分分析,获得水射流喷丸强化增益效果及疲劳裂纹萌生机制,指出水射流喷丸可以提高两种材料的表面显微硬度、表面残余压应力和疲劳寿命,并存在最大表面显微硬度靶距和最大表面残余压应力靶距,在试验条件下,2A11铝合金和45钢喷丸疲劳试样比未喷丸疲劳试样的疲劳寿命分别最大提高1.74倍和2.67倍,且水射流喷丸疲劳裂纹萌生位置的机制与传统喷丸相同。

Test research of water jet peening strengthening

In order to obtain the effect laws of water jet peening strengthening effect on peened material surface mechanical properties and fatigue life，chosen peening pressure，movement velocity，target distance as effect factors，did peening test to 2A11 aluminum alloy and 45 steel by water jet.The micro hardness tester and X- ray stress analyzer were used to respectively determine peened surface micro hardness and surface residual stress.The scanning electron microscope was used to observe the fatigue fracture morphology，the energy dispersive spectrometer was used to analyze inclusions composition in the area of internal fatigue source，got the water jet peening strengthening amplification effect and fatigue crack initiation mechanism.It is indicated that water jet peening can improve the surface micro hardness，surface residual press stress and fatigue life of both materials，the biggest surface micro hardness target distance and the biggest surface residual press stress target distance exist.Under test conditions，the fatigue life of peened samples on 2A11 aluminum alloy and 45 steel，respectively，increases 1.74 times and 2.67 times at most than that of initial samples，moreover，the mechanism of the fatigue crack initiation position with water jet peening is the same to traditional peening.