The Improvement Of Fatigue And Surface Charac.of Alloy 7075-t6 By Secondary Peening With Glass Beads

Author:  Snowman, A. and Schmidt, R.G.
Source:  Conf Proc: ICSP-1, (p.313-322)
Doc ID:  1981075
Year of Publication:  1981
Abstract:  
Metallic shot peening, first developed in the late 1920's, is recognized as an excellent process for increasing the fatigue life of metals. Glass bead peening is a newer technique for which quantitative data has been lacking. Consequently, a series of studies were initiated to determine the effects of glass bead peening on the fatigue life of aluminum alloys. Previous studies at Potters showed that when 7075-T6 aluminum alloy sheet specimens were peened with either glass beads or steel shot, equal increases in fatigue life resulted, providing the operations were performed at the same arc height peening intensities. In this study, steel shot peened specimens were given a second peening operation with glass beads and the data showed that this technique resulted in a further improvement in fatigue life, as well as a significant reduction in surface roughness. The paper describes the methods used to obtain and evaluate these improvements and presents the fatigue life data, together with a discussion of the improved surface characteristics. Descriptors: Shot peening; Aluminum alloy; 7075-T6; Glass beads; Fatigue life; Surface roughness; Arc height