الفهرس 
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Abstract
Copper (Cu) matrix reinforced with three different ratios of 3, 6, and 9 wt. % nano TiC and/or nano Al₂O₃ are prepared by powder metallurgy technique. Copper powder is mixed mechanically with nano TiC and/or nano Al₂O₃ for 24 hrs. by 25:1 ball to powder ratio and 110 rpm. Stearic acid is added by 1.5 wt.% as a process control agent. Spark plasma sintering (SPS) is used to consolidate the compacted composite powder at 950 °C for 45 min. The physical, mechanical, tribological, and structural behavior of the composites after SPS are investigated. Microstructural characterization showed that titanium carbide was distributed uniformly in the Cu matrix in a homogeneous manner. Whereas alumina nanoparticles showed some agglomerations at Cu grain boundaries. The crystallite size exhibits a clear reduction with an increasing reinforcement weight ratio. Also, increasing the TiC and Al₂O₃ nanoparticles content in the Cu- Al₂O₃ /TiC composites reduced the relative density from 95% for Cu-1.5 wt. % TiC & 1.5 wt. % Al₂O₃ to 89% for Cu-4.5 wt.% TiC & 4.5 wt.% Al₂O₃. The addition of TiC/ Al₂O₃ reinforcements to the copper matrix induces a significant increase in the hardness, yield strength (YS), ultimate compression strength, and ductility sustain at a comparatively great level, while the density followed a reverse trend. The mechanical test results demonstrated that the Cu/ Al₂O₃ nanocomposite containing 9 wt.%, Al₂O₃ had the highest hardness value of about 211 HV (more than the monolithic copper by " ~ " 260.5 %), while the Cu/Al₂O₃ nanocomposite containing 6 wt.%, Al₂O₃ recorded the highest yield strength value of 610 MPa (more than the monolithic copper by " ~ " 477 %). The highest electrical and thermal conductivities are recorded for the Cu-TiC that were (20.87 MS/m) and (149.82 W/m.k) respectively. The Cu/TiC nanocomposite containing 9 wt.%, TiC had the lowest wear rate value (1.7×10-3 g/min) at 25 N loads.