In-situ microscopy investigation of failure mechanisms in Al/SiC p metal matrix composite produced by laser embedding

Abstract

Laser surface treatments are suitable techniques for improving the mechanical, tribological and chemical properties of metal surfaces. In the laser injection process the laser beam interacts primarily with the substrate and to a lesser extent with the particles, which are simultaneously injected into the melt pool produced by the absorbed laser power density. Metal Matrix composite (MMC) layers with interesting properties and very good connection to the metal substrate may be prepared by a selection of suitable combination of metallic substrate and ceramic particles. In this study Al/SiC MMC layers prepared by laser injection of SiC particles into Al substrate were mechanically tested to reveal the weakest structural components from a mechanical point of view. The objective is to obtain accurate information about the initiation and propagation of cracks in such heterogeneous structures by microscopic inspections of the sample surface during the loading. A combination of techniques was used to characterize the nucleation and progress of fracture: i.e., in-situ microscopy observations during testing and by conventional fractographic methods after failure.