Morphology and Mechanical Properties of Al- TiC Nanocomposite Processed via Ball Milling Technique

Abstract

Al-TiC nanocomposites are prepared by powder metallurgy technique. The effect of milling time and TiC percent on the mechanical properties and microstructure are studied. Nano TiC powders with 5, 10, and 20 wt. % is added to the Al matrix. The mixed powders are mechanically milled by a 35:1 ball to powder ratio and 110 rpm for 6, 12, 24, and 48 hr. milling time (MT). Mixed powders are compacted by a uniaxial press under 600 Mpa and sintered at 600 °C for 1 hr. in a vacuum furnace. According to Archimedes’ principle, the density was estimated, which indicated it is decreasing for 6 hr. milling time, followed by an increase for 12 and 24 hrs., then another decreasing for 48 hrs. The addition of nano TiC increases the density values gradually by increasing its percent. Both the phase composition and microstructure of both composite powders and sintered samples are examined using XRD & FE-SEM, respectively. XRD results indicated forming the aluminum carbide (Al4C3) phase that is formed during the sintering process. The microstructure shows the homogeneous distribution of TiC on the Al matrix and the reduction of Al particle size by increasing both milling time and TiC percent. Hardness, compression strength, and wear resistance are improved by increasing TiC content and MT up to 24 hours. Al-20 wt. % TiC composite with 24 hr. milling time exhibited the highest hardness (196.5667 HV) and the lowest wear rate (0.001 g/min).