Microscopic study of Al-SiC particulate composites processed by laser shocks

Coatings of composite Al + 50 wt% SiC were initially deposited using the hi gh velocity oxy-fuel (HVOF) technique and subsequently submitted to shocks generated by a Nd:glass laser. The as-sprayed and laser-treated samples of the coatings were analyzed with an optical microscope (OM) and a transmissi on electron microscope (TEM). The OM study evidenced the improvement of the contact between the aluminum matrix and SIC reinforcement in the laser sho ck-treated samples. TEM investigations enabled us to find a high concentrat ion of linear defects at the surface of the samples. These defects, indicat ing the plastic deformation of the aluminum matrix, are related to the poor performance of laser-treated composites in the sliding wear tests. (C) 200 0 Elsevier Science S.A. All rights reserved.