Mechanical Surface Treatment Technologies for Gas Turbine Engine Components

Abstract

Various mechanical surface treatment technologies have been invented and developed to induce a protective layer of compressive residual stress at the surface of gas turbine engine components where the operating loads are tensile dominated. The benefits of these surface treatments are to prevent crack initiation, to retard propagation of small cracks, and even to resist corrosion and wear damage. In this paper the literature on these technologies and their effects on component reliability and durability is reviewed, with an emphasis on shot peening (SP), laser shock peening (LSP), and low plasticity burnishing (LPB). The relative advantages of these three surface treatment technologies, as well as their limitations, are identified and evaluated. The most important issues for these three technologies, and the relative merits of the resultant residual stress fields, are presented and discussed with a view to enhancing gas turbine engine component operating lives.