Microstructure and Thermophysical Properties of Hot-pressed Cu/FeCoCr Composites

Series of micro-scale powders with composite microstructure based on CuFeCoCr system were successfully designed and fabricated using CALPHAD approach (calculated from phase diagrams) and gas atomization method. The bulk CuFeCoCr composites were produced by hot pressing technique at 950℃ under a pressure of 45 MPa. The effect of Cu content on the microstructure, coefficient of thermal expansion (CTE), thermal conductivity (TC) and micro-hardness (HV) were systematically studied. The results show that the CuFeCoCr composites present a microstructure of two separate fcc phases (Cu-rich and FeCrCo-rich phase). After annealing at 500℃ for 8 h, the CTE of the composites ranges from 5.83×10^-6~10.61×10^-6 K^-1 and TC varies from 42.17 W•m^-1•K^-1 to 107.53 W•m^-1•K^-1. Particularly, the Cu₅₅(Fe_0.37Cr_0.09Co_0.54)₄₅ composite exhibits excellent comprehensive properties, i. e. CTE of 9.08×10^-6 K^-1 and TC of 91.09 W•m^-1•K^-1, which match well with the properties of semiconductors for electronic packaging.