Fabrication of magnesium sheet with magnesium matrix surface composite to improve hardness and wear properties

Nowadays, there is an increasing demand for magnesium and its alloys as the lightest commercial metal with a high strength to density ratio. Nevertheles, afew undesirable properties, such as low hardness and poor wear resistance, have limited the applications of this exclusive metal. Fabrication of magnesium matrix composite could improve hardness and wear resistance in addition to strength increasing. Since converting all of a metal piece to composite could make it more brittle and increase the costs, fabrication of surface composite could be a solution. In this paper, a magnesium sheet with a surface composite has been fabricated by applying warm rolling process. Indeed, a layer of magnesium matrix composite (which has been fabricated by stir-casting) has been conjoined to a magnesium substrate layer using a zinc interlayer. This method could increase the production speed and decrease the costs. In addition to the connection of two layers together, the zinc interlayer would preserve the surfaces of the layers from oxidation without using any controlled atmosphere. The results show a proper connection between the surface composite and the substrate. According to the microhardness results, the hardness of surface composite increased about 23% and 52% in the cross-section and the surface, respectively. Moreover, wear resistance of surface composite improved about 43% in comparison to magnesium substrate. Also, wear rate decreased in the surface composite.