Effect of initial surface topography on the surface status of LY2 aluminum alloy treated by laser shock processing

• Published in: Vacuum Vol. 86; no. 10; pp. 1482 - 1487
• Main Authors: Dai, F.Z., Lu, J.Z., Zhang, Y.K., Luo, K.Y., Wang, Q.W., Zhang, L., Hua, X.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 27.04.2012
• Subjects: Aluminum base alloys; Compressive properties; Laser shock processing; Microhardness; Profilers; Residual stress; Surface roughness; Surface topography; Topography; Laser shock processing; Surface topography; Microhardness; Residual stress
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2012.02.001

Samples manufactured by LY2 aluminum (Al) alloy with different initial surface topography were treated by laser shock processing (LSP), and then the surface topographies before and after LSP were carefully investigated with a non-contact optical profiler (NCOP). Moreover, the residual stress and microhardness were also examined. Results showed the following three aspects: (a) Initial surface topography will influence the surface roughness of LY2 when treated by LSP. The values of surface roughness of all the tested samples would tend to be stable after one LSP impact, and there was an ultimate value for the surface roughness after multiple LSP impacts, which was about 0.58 μm. (b) With the increase of initial surface roughness, the compressive residual stress decreased when subjected to one LSP impact. The surface residual stress of all the samples tended to be saturated after three LSP impacts, and the saturated value was nearly equal. (c) With the increase of initial surface roughness, the microhardness of all the samples increased when subjected to one LSP impact. ► LY2 Al alloys with different initial surface were prepared and then treated by LSP. ► The surface roughness of LY2 Al alloy tends to be stable after one LSP impact. ► The surface roughness tend to be saturated (∼0.58 μm) after multiple LSP impacts.