Analysis on the effect of pressure and mass fraction of chromium to mechanical properties and electrical conductivity of copper-chromium composite in hot compaction process

Cu-Cr composite is used in the electronic industry as a material which is directly connected to the electricity, as a component of a circuit breaker, cable contact, circuit board, etc. In this study, hot compaction method was employed to manufacture Cu-Cr composite which has excellent hardness and electrical conductivity. Composite manufacturing was based on powder metallurgy technique while mixing used mechanical milling method in regards to its better homogeneity. Hot compaction process set at the temperature of 300°C was applied to the powder material to increase the plasticity so the compaction can be done easier. Some variation was made on the composition of Cu: Cr ratio (90: 10, 80: 20, 70: 30, and 60: 40), and the compaction pressure (500, 700, and 1000 MPa). Sintering was conducted at 85°C with holding time of 1 h. Based on the results, the optimum sintering density of 96.81% of its theoretical density was obtained at Cu: Cr ratio as of 80: 20. Maximum hardness at 60%Cu: 40%Cr and P = 1000 MPa was 129 VHN. And, electrical conductivity was reached its optimum value of 82.6% IACS when the Cu:Cr ratio was 90:10 at P = 1000 MPa.