Abstract:To improve the surface properties, lining of magnesium alloys with hard powders by shot peening was carried out in order. The hard powders were tried to bond to the workpiece surface due to the collision of many shots. In order to fix the hard powders to the surface of the workpiece, the powders were set on an uneven surface. To easily facilitate fixing of powders, lining of the workpiece with the powder sandwiched between two aluminum foil sheets was also attempted. In this experiment, a centrifugal shot peening machine with an electrical heater was employed. The workpieces were magnesium alloys AZ31B and AZ91D, and the hard powders were commercial cemented carbide, alumina, and zirconia. The joinability of hard powders near the lined surface was observed by a optical microscope. The wear resistance was also evaluated by a wear test. The hard powders were successfully bonded to the surface of workpieces by the shot lining process. The results show that the present method is effective in wear resistance of the magnesium alloys.

Key words: shot peening; surface treatment; lining; joining; joinability; magnesium alloy; hardness; wear resistance; cemented