ショットライニングによるAZ31合金の表面改質

抄録

Magnesium alloys are the lightest of all practical metals, and are relatively abundant in terms of resources and easier to recycle than plastics. However, compared to steel materials, magnesium alloys have low corrosion resistance and wear resistance, are prone to ignition, and are difficult to process, which are issues in their practical use. In the present study, the surface of magnesium alloys was modified by joining dissimilar materials using shot peening. The test material was an extruded magnesium alloy AZ31, and the workpiece was 50 mm in diameter and 5 mm thick. The dissimilar materials were laminated materials consisting of a resin sheet containing ceramic powder and a corrosion-resistant metal foil. The ceramic powder was alumina with a diameter of 0.1 mm. The corrosion-resistant metals were pure aluminum, pure titanium, pure copper, and pure nickel. The joining was performed using a cast steel shot with a diameter of 1 mm at a projection speed of 60 m/s and a projection time of 10 s. The joining property was evaluated by observing the cross section near the surface and by bending tests, and the wear resistance was evaluated by wear tests. The use of pure aluminum foil as an insert material and warm processing were effective in improving the joining property of the dissimilar materials. Additionally, wear tests showed improved wear resistance.