Electrical and Mechanical Properties of Cu Matrix Nanocomposites Reinforced with Yttria-Stabilized Zirconia Particles Fabricated by Powder Metallurgy

Copper matrix nanocomposite powders reinforced with 8 mol% yttria-stabilized 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.% and 5 wt.% zirconia (8-YSZ) particles were synthesized by mechanical alloying under a high purity argon atmosphere in an Attritor ball mill. Cu and Cu-ZrO2 powder mixtures were compacted with a compressive force of 500 MPa in a steel mold of 10 mm in diameter and sintering was performed at 900 ◦C for 2 h in argon atmosphere. With the study of the microstructure done by scanning electron microscope (SEM) with energy dispersive spectrometer (EDS), it was shown that there is uniform distribution of the reinforcement in the Cu matrix and nanocomposites with the least porosity are developed. The micro-hardness and density results showed that the gain in micro-hardness was found to be dependent on the zirconia contents rather than on the relative densities. The zirconia content up to 5 wt.% resulted in an increase of 54.55% in micro-hardness and slight decrease (3.7%) in relative densities. The results of compression tests showed increase in compression strength (22.08%) as zirconia content increased up to 5%. Maximum electrical conductivity of test materials ranged from 88.0% IACS to 59.7% IACS.