Microstructure And Properties Of Domestic M40/Al Composites

In this paper, domestic M40/Al composites were fabricated by pressure infiltration process. Microstructure observation and physical property test were used to analyze the effect of Mg content on the microstructure, physical property and thermophysical properties of domestic M40/Al composites.Microstructure observation indicate that the surface of domestic M40 is rougher then Toray M40. Domestic M40’s degree of graphitization is lower than Toray M40, but its surface’s graphitization is higher. The main interface reactant of M40 / Al composites is Al4C3. With the increase of Mg content, the generation amount and size of Al4C3 decreased, when the content of Mg reach a certainty value, the formation of Al4C3 is restrained.The physical properties studies have shown that: the elastic modulus of the three kinds of domestic M40/Al composites are almost the same, because o f the strength of interface has no obvious effect for the elastic modulus. With the increase of Mg content, the tensile strength of domestic M40/Al increased, the tensile strength of domestic M40/5A06 is the highest(1010.9GPa). But the corresponding transverse tensile strength gradually reduces, only reach 1/6, 1/10 and 1/20 of the longitudinal tensile strength, respectively. In the same time, with the increase of Mg content, the interfacial bonding weakened and the interlaminar shear strength decreased, but the thermal expansion increased. With the rise o f temperature, The thermal expansion of the three kinds of domestic M40/Al composites all presents a tendency of increase first, then decrease, and then increase.Compare the physical properties of domestic M40/Al and Toray M40/Al, the tensil strength of domestic M40/Al increase 189.9GPa,132.6GPa and 104.9GPa respectively. That’s beacause of domestic M40 has a higher tensile strength, and the Al4C3 of the interface is lesser. So compared with Toray M40/Al, domestic M40/Al has a lower interfacial bonding strength.