Effect of Y addition on the interfacial microstructures and mechanical properties of Cf/Mg composites

Magnesium (Mg) alloy containing 1 wt% Yttrium (Y) reinforced with 60 vol% carbon fiber (Cf) composites was fabricated by the pressure infiltration method. The morphological study with Y addition in the composite revealed that the Y element was prone to segregate on the surface of the carbon fiber during the fabrication process, forming plate-like intermetallic compound Mg2Y. The mechanical properties of the composite were investigated by a flexure test and a short-beam shear test. The results showed that the addition of Y element to the composite improved the bending strength and interlaminar shear strength greatly. A study of the fracture mechanism uncovered the important role of Y addition on the interface bonding strength of the Cf/Mg composite.