Effect of Shot Peening on Bending Strength of Magnesium Pipe

• Published in: MATERIALS TRANSACTIONS Vol. 57; no. 6; pp. 966 - 972
• Main Authors: Harada, Yasunori, Fukuda, Izumi, Yamamoto, Atsushi
• Format: Journal Article
• Language: English
• Published: Sendai The Japan Institute of Metals and Materials 01-01-2016; Japan Science and Technology Agency
• Subjects: Automotive electronics; Axial loads; Bend strength; Bend tests; bending; bending strength; compression test; Compressive properties; Compressive strength; deformation twin; Electron back scatter; electron backscatter diffraction; Lateral loads; magnesium alloy; Magnesium alloys; Magnesium base alloys; material testing; Pipe; Pipes; Shot peening; Surface layers; surface treatment; tension test; Wall thickness; Workpieces; Yield stress
• ISSN: 1345-9678; 1347-5320
• DOI: 10.2320/matertrans.P-M2016811

This paper deals with the effect of shot peening on the bending strength of an AZ31 magnesium alloy pipe. Magnesium alloy has a wide range of application prospects in the automobile and electronic industries. AZ31 alloy is the most widely used commercial magnesium alloy. In our experiment, extruded pipes of 22 mm O.D., 18 mm I.D., and 2 mm wall thickness were used. Shot peening treatments were applied to the surface of the workpiece using an impeller-type or an air-type peening machine. Tensile and compressive tests were carried out under axial load at a crosshead speed of 10 mm/min, and bending strength tests were performed at a crosshead speed of 100 mm/min under lateral load using an Instron-type testing machine. In the bending tests, the peened workpiece could withstand higher bending yield load. The surface layer of the peened workpieces was also observed by electron backscatter diffractometry (EBSD). It was found that multiple deformation twins were formed during shot peening. The results of the present study revealed that the compressive yield stress of shot-peened pipes is strongly related to their bending strength.