Effect of the matrix alloy on the fracture type and bending strength of the carbon-aluminum composites

Abstract

composite with a metal matrix fabrication is one of the most important. In the case of carbon-aluminum composites, the choice of alloy affects the possibility of the brittle carbides formation and the bond strength at the matrix-fiber interface, which determines the nature of fracture and the ultimate strength of the composite material.In this work, unidirectional composite materials with matrices of aluminum alloys grades A7, AMg4 and AK12, reinforced with continuous carbon fibers, were obtained and investigated. Mechanical tests for three-point bending and microstructural studies of the composite materials fracture surfaces were carried out. It was found that aluminum alloys, which contain magnesium (AMg4) or silicon (AK12), can reduce the chemical interaction of the composite components and increase the material strength as a whole. Thus, the three-point bending strength of composites with matrices A7, AMg4, and AK12 was 288, 389, and 413 MPa, respectively. In this case, the nature of specimen fractures correlates with the obtained strength values.