Surface Strengthening of Aerospace Material of Inconel 718 by GOV (Flow Peening) Process

Abstract

Inconel 718 was experimentally investigated in this paper due to the excellent mechanical properties and broad application area in aerospace industry. The purpose of current study is to improve surface strength of Inconel 718 samples having undesired white layer and microcracks because of electrical discharge machining process. In this research, newly developed GOV (flow peening) process by benefiting the superior capabilities of shot peening and abrasive flow machining such as generating compressive residual stresses which increases the corrosion resistance, surface strength, fatigue life and surface enhancement is applied to strengthen surfaces. SEM images were evaluated to verify the results of GOV process performance parameters on microhardness, residual stress, surface roughness and white layer removal. Consequently, compressive residual stress of - 1173.3 MPa, surface hardness of 545.5 HV and surface roughness Ra value of 0.46 mu m were obtained for Inconel 718 by GOV process.