Effects of Laser Shock Peening on Corrosion Resistance of Additive Manufactured AlSi10Mg

Mechanical properties of Al alloys make them an ideal candidate for different sections of marine, aerospace, automotive, etc. industries. Recently taking the advantages of additive manufacturing (AM), many complex infrastructures/components can be fabricated with very high design freedom via Al alloys. Although Al alloys have good natural corrosion resistance, however improving this property attracts lots of attention in the past few years. Post-processing methods can play a key role for addressing the issues related to internal and surface anomalies associated with as-built AM parts. Generally, these anomalies have detrimental effects on mechanical properties. In the present study, the effect of laser shock peening (LSP) treatment with different laser pulse overlaps and energies was investigated comprehensively on microstructure, surface texture, porosity, hardness, residual stresses as well as corrosion resistance of laser powder bed fused (L-PBF) AlSi10Mg samples. LSP provides strain deformation on the surface, and the deformation enhances by laser beam energy. LSP1 (laser energy of 1.5 J and 50% overlap) and LSP3 (laser energy of 4.5 J and 50% overlap) introduce maximum local strain of 7.5 and 10.7, respectively. The surface roughness of as-built state mu m in terms of Rv was effectively diminished to 16.33 after LSP6 (laser energy of 4.5 J and 75% overlap). The results indicated that due to the modified surface texture, improved hardness and induced high compressive residual stresses in the surface layer. (surface hardness improvement and inducing high surface compressive residual stresses were obtained after LSP6 up to 26% and 289 MPa, respectively); the LSP treated samples exhibited higher corrosion resistance with the corrosion rate decreasing down to 50% as compared to the as-built state.

Automated summary

The mechanical properties of Al alloys make them ideal for various industries such as marine, aerospace, and automotive. Additive manufacturing (AM) has been used to fabricate complex infrastructures/components using Al alloys with great design freedom. Improving the corrosion resistance of Al alloys has been a focus of research. Laser shock peening (LSP) treatment with different laser pulse overlaps and energies was investigated in this study, and it was found that LSP treatment improved microstructure, surface texture, porosity, hardness, residual stresses, and corrosion resistance of laser powder bed fused (L-PBF) AlSi10Mg samples.