EFFECTS OF RARE-EARTH-METALS ON ELECTRICAL-CONDUCTIVITY AND MECHANICAL-PROPERTIES OF COMMERCIAL PURITY ALUMINUM

The effects of the addition of rare earth metals on the electrical con ductivity and mechanical properties of commercial purity have been inv estigated both in the laboratory and in industrial trials. The electri cal conductivity of commercial purity aluminium is increased by about 1% on the international annealed copper standard by the addition of la nthanum, and both its tensile strength and elongation are improved con siderably by the addition of cerium. Investigation of the microstructu re of the alloys containing rare earth metals shows that the apparent improvement in the electrial conductivity of commercial purity alumini um is caused by a decrease in the solid solubility of impurities in al uminium.