Thermal expansion behavior of Cu/Cu2O cermets with different Cu structures

Cu/Cu₂O cermets were prepared with Cu₂O matrix imbedded with branch-like or spherical Cu powders. The coefficients of thermal expansion (CTE) of them were tested. The CTE curves can be divided into three segments. From 25 °C to 150 °C, CTEs were found to decrease with temperatures. The CTEs were influenced by the structure of the conductor phase. For cermets prepared with spherical Cu, the increase in CTEs was basically linear with temperatures above 150 °C. In contrast, cermets with same Cu content prepared with branch-like Cu had a CTE with an increasing rate as the temperature rose from 150 °C to 900 °C, and the increasing rates in these temperature range are much higher than those prepared with spherical Cu.