The Wear Behavior of In-Situ Al-AlN Metal Matrix Composites

摘要

A1-A1N composites are synthesized using NH_4Cl + CaO powder as a nitrogenation precursor in the melt of pure aluminum. In-situ formation of A1N to varying volume fraction is attempted using different proportion of NH4Cl + CaO precursor into the aluminum melt held at 700 °C. Mechanical properties of synthesized metal matrix composites are evaluated for different volume fraction and distribution of A1N particles in aluminum matrix. Agglomeration of A1N is noticed with increasing precursor addition and synthesis time into the aluminum matrix. Due to heterogeneous distribution of A1N particles in aluminum matrix, marginal changes in hardness are observed. Pin on disc, dry sliding wear of metal matrix composites is carried to study wear behavior of synthesized composites. Composite with good dispersion of A1N particulates has shown higher hardness and wear resistance. Present paper discusses wear behavior of composites with different weight fraction of A1N tested under load and sliding distance as wear parameters. The shearing mechanism of agglomerate due to friction and its correlation with the wear loss is also highlighted in the present paper.