Experimental investigations into mechanical response and damage mechanisms of fiber aluminum hierarchical composites

Abstract

Carbon fiber reinforced aluminum matrix hierarchical composites have attracted the attention as a potential lightweight material for aerospace. Two typical Cf/Al composites were prepared by pressure infiltration method with changing the infiltration pressure. The analysis of microstructure, mechanical properties and failure behavior were carried out to systematically reveal the damage mechanisms of composites to realize their full potential. The results show that the infiltration process and solidification behavior of composites can be revealed by analyzing the evolution law of macrosegregation and microstructures. Compared with the matrix alloy, the bending strength of H-Cf/Al composites increased by 47%, and the compression strength of P-Cf/Al composites increased by 128%. To clarify the crack propagation behaviors of H-Cf/Al composite, toughening mechanisms such as crack deflection, crack bridging, and crack branching are discussed. The shear tests show that the failure characteristics of H-Cf/Al composites are mainly fiber bundle interface cracking, while the strong interlaminar shear strength of P-Cf/Al composites dominated by fiber splitting is attributed to serious interface reaction. In addition, main damage mechanisms affecting the ultimate failure were identified, namely interface splitting cracks, plastic deformation of matrix and fiber damage. This study provides meaningful enlightenment for the preparation and application of fiber-reinforced metal matrix composites.