Study of rare earth elements on the physical and mechanical properties of a Cu–Fe–P–Cr alloy

The influence of rare earth elements (mischmetall, containing mainly La and Ce) on a high-strength and high-conductivity Cu–Fe–P–Cr alloy was investigated by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), resistivity analysis, hardness analyses, and tensile tests, etc. Experimental results show that appropriate addition of rare earth elements (Re) can effectively improve the physical properties (electrical conductivity and temperature to softening) and the mechanical properties of the alloy by facilitating the precipitation of the strengthening phases, making the strengthening particles finer and well dispersed in the matrix, refining the matrix microstructure, etc. Excessive addition of Re can deteriorate the properties of the alloys. The results were discussed in relating to the metal purifying and to the strengthening mechanism in Cu–Fe–P alloy.