Studying the Microstructure, Physical and Mechanical Properties of Al Matrix Reinforced with Bi-Modal Particles Coated with Either Ni or Cu

Abstract

Powder metallurgy was used to fabricate Al/(SiC-Y2O3)/Ag/Cu or Ni nanocomposite. The ratio of SiC to Y2O3 was 50:50. SiC-Y2O3 particles were coated with 10 wt% nano-Ag, followed by coating with another layer of 10% nano-Ni or nano-Cu by an electroless chemical deposition technique. All samples were compacted by a uniaxial press under 480 MPa and then sintered in a vacuum furnace at 600 °C for 1 h holding time. Coated samples with nano-Cu have the highest densification values. The microstructure of nano-Cu-coated composites is more homogenous than nano-Ni ones. X-ray diffraction analysis (XRD) indicated the presence of Al peaks as a major phase, and Al3NiSi and AlCu intermetallics are detected. Also, traces of SiC and Y2O3 peaks are recorded. Hardness results showed that (SiC-Y2O3)/ nano-Ag/nano-Cu samples have higher hardness values than nano-Ni samples. Also, both the electrical and thermal conductivities are higher for nano-Cu-coated samples than for nano-Ni coated ones.