Sintering of a metal matrix composite Cu-Ti-TiC assisted by abnormal glow discharge

Abstract

A metal matrix composite based copper with ceramic reinforcement at 1% w/w of titanium carbide had been studied under variable titanium at 10%, 15% and 20%, in order to evaluate the microstructure and tribological properties (coefficient of friction and wear rate) in the composite material after abnormal glow discharge sintering. The metal matrix composite was manufactured by powder metallurgy process that included: mechanical and ultrasonic mixing in a suspension of 2-propanol, compaction at 200 MPa and sintering by abnormal glow discharge in an atmosphere of 10% nitrogen and 90% argon. As a result, a differentiation in the morphology and properties had been found due to the temperature, this effect was related with diffusion phenomena and energy provide by the plasma process. The final porosity of the samples at 750 °C decreases with titanium increments, reach to 2.6% with 20%. Additionally, in the grain limits of the titanium particles were detected CuTi and CuTi2 phases. On the other hand, at 850 °C the porosity increased with concentration of titanium, a value of 16.8% was shown at 20%. Furthermore, intermetallic phases as Cu3Ti, Cu4Ti, CuTi2 had been identified in the sintered at 850°C. Tribological properties had evidenced that the samples at 750 °C with Ti contents of 20% presented a wear rate value of 7.2x10−8 mm3.N−1.m−1, despite the porous morphology of the compound at 850 °C was estimated in 2.0x10−8 mm3.N−1.m−1 with concentration of 20%.