Microstructure and high-temperature wear/oxidation behaviors of TiN/TC4 composites in-situ fabricated by laser melting deposition in N2-containing atmosphere

The TiN/TC4 composites were in-situ fabricated by laser melting deposition in N2-containing atmosphere to investigate their microstructure and high-temperature wear/oxidation behaviors. The well-dispersed TiN reinforcements hindered the growth of grains and facilitated the formation of equiaxed grains. The wear tests at 400 °C indicated that the composite with 25 vol% N2 exhibited the best wear resistance due to its relatively fine grain structure and high microhardness. The oxidation tests at 400 °C demonstrated that the composite with 25 vol% N2 also possessed the best anti-oxidation ability, which is attributed to the existence of a more protective oxidation layer composed of TiO2 and Al2O3.