Effects of TiO_2 coating on microstructure and mechanical properties of magnesium matrix composite reinforced with Mg_2B_2O_5w

摘要

The interface between the reinforcement and the matrix is very important for metal matrix composites. The effects of TiO_2 coating on microstructure and mechanical properties of Mg_2B_2O_5w-reinforced AZ91D magnesium matrix composite fabricated by squeeze casting technique were studied. The results indicate the flexural strength and flexural modulus of Mg_2B_2O_5w/TiO_2/AZ91D composite is 40% and 35% up on that of Mg_2B_2O_5w/AZ91D composite. The reason is that the MgO interfacial product resulting from the reaction between the TiO_2 coating and the liquid Mg can enhance the interfacial bonding strength and increase the load transfer from the matrix to the reinforcement, which leads to higher mechanical properties of Mg_2B_2O_5w/TiO_2/AZ91D composite.