Study on the Effect of Multi Pass ECAP with Back Pressure on Microstructure and Hardness of Cu-Fe Composite Produced by Powder Metallurgy with Ni Nanoparticle

The main goal of this study is to produce the copper-iron composite by powder metallurgy method and to investigate its microstructure and hardness after ECAP process. The copper with atomized iron with a grain size less than 63 microns were mixed with the ratio of 9:1, then pressed inside a cylindrical mold at the pressure of 450 MPa. The samples were compacted and sintered in a tunnel kiln with a temperature of 920 °C, then their surfaces were ground and subjected to a multi-pass ECAP process with back pressure. The performed evaluation indicate that the hardness for the sintered Copper-Iron metal matrix composite sample prior to the ECAP process was increased up to 190% after third pass. The average grain size of iron-copper composite in three pass decreased to 53% compared to the same composite on one pass. The theoretical density of the samples increased significantly after the ECAP process, so that the density value increased from 88% for the raw sintered sample to 98% for the samples in the three-pass ECAP condition.