Effect of laser shock peening with and without protective coating on the microstructure and mechanical properties of Ti-alloy

•A high potential of LSP to improve surface and mechanical characteristics.•Laser interaction increases the surface parameters and average roughness increased.•Surface topology better results with the use of transparent and protective layer.•Interaction of laser beam increases the microhardness in all case. Owing to their good mechanical properties, titanium based alloys are used for machine parts and devices that operate in demanding regimes and environmental conditions. Laser shock peening (LSP) is an innovative technique for improvement of the surface and mechanical characteristics of the material. In this paper, LSP is employed for additional improvement of already good characteristics of Ti- alloy. Laser shock peening is performed on alloy surface, with and without protective and transparent layer and obtained microstructure, surface characteristics and mechanical properties are compared. LSP improved the surface topology and microhardness of material, producing overall better results when the Ti-alloy surface was coated by transparent and protective layer.