Low-Plasticity Burnishing

Low-plasticity burnishing (LPB) has been devel- oped as an affordable means of imparting residual compressive stresses to surface layers of metal parts (especially engine components) in order to increase their fatigue lives. Heretofore, surface compressive stresses to enhance the fatigue lives have been produced, variously, by shot peening or laser shock peening. Unfortunately, thermal relaxation has been found to result in loss of the needed surface-layer compressive stresses, with consequent shortening of component lives and reduction of engine performances. Hence, what is needed is a means of imparting thermally stable surface compression.