铝合金7075T651高压水喷丸强化工艺试验研究

Experimental research on the high pressure water jet peening process for aluminum alloy 7075T651

高压水喷丸强化是金属表面强化的新方法,即利用在水中的高压水射流所产生的气穴效应打击金属零件表面,从而对零件进行表面强化的工艺。基于不同的高压水喷丸强化工艺参数,对航空常用铝合金材料7075T651开展高压水喷丸强化试验,分析了强化试件的表面形貌、表面质量、表面残余应力以及强化层组织结构。结果表明,液体冲蚀过程中会产生气泡多次溃灭现象,由此产生同心圆环形强化区域;喷射压力和喷射距离是影响材料表面质量和残余应力分布的重要工艺参数;高压水喷丸强化后强化层晶体取向发生了改变,晶粒明显细化,为原始组织晶粒度的66.7%。

The high pressure water jet peening（ WJP）,as a new kind of surface peening method which blow the surface of metal by means of a submerged high speed water jet with cavitation,is used to peen the surface of treated components. The submerged water jet peening experiments for aluminum alloy 7075T651 which is widely used in aerospace industry were conducted based on the different process parameters of WJP. The surface morphology,surface quality,residual stress distribution and structure of the treated specimen surface were investigated. Results show that concentric ring strengthen area is generated by bubbles breaking phenomenon during water jet peening process. The peening pressure and peening distance are important process parameters which effect the surface quality and residual stress distribution of treated specimen. It is found that the orientation of phase particles in 7075T651 change near the peened layer surface after WJP,and the grain size is refined obviously,which is about 66. 7% of initial grain size.