在普通喷丸设备上加增压罐,采用增压喷丸方法对7050铝合金表面进行喷丸处理;用X射线衍射仪、光学显微镜、透射电镜、选区电子衍射仪等对合金表层结构进行了观察与分析,并用显微硬度计测试了表层的硬度.结果表明:经增压喷丸处理后7050铝合金表层的衍射峰明显宽化,随着处理时间的增加,塑性变形层厚度增加,表层晶粒细化至纳米级,平均晶粒尺寸约为40 nm;纳米化后的合金表层硬度比心部硬度提高了1.5倍,其原因可归结为细晶强化及加工硬化.

A technique called added-pressure shot peening (APSP),which combined with a pressurizing vessel in the common shot peening equipment,had been applied to shot peen on the surface of 7050 aluminium alloy.X-ray diffraction,optical microscope,transmission electron microscopy and selected area electron diffraction were employed to observe and analyze the surface microstructure as well as microhardness tester for the microhardness of the surface layer.The results show that after treatment the diffraction peak of the alloy surface brodened obvionsly.The thickness of plastic deformation layer increased as the treatment time increase,the surface layer grain was refined into nanometer about 40 nm.The microhardness of nanostructure surface increased by 1.5 times which could be attributed to reduction of grain size and work hardening.