Ａｌ‐Ｃｅ‐Ｘ ３元系合金の急冷凝固Ｐ／Ｍ材

Abstract

Rapidly solidified flakes of Al-10mass%Ce based alloys with additions of Fe, Mn, Cr, Ni or Si were prepared by atomizing and subsequent splat quenching onto a water-cooled copper roll. Consolidation of the flakes was done by cold pressing, vacuum degassing and hot extrusion. Metallography and constituent phases of the flakes and P/M materials were examined. Mechanical properties of the as-extruded P/M materials were examined by tensile tests at room and elevated temperatures. Formation of the primary crystals of the additional element compounds is suppressed at high cooling rate. The microstructures of the as-extruded P/M materials consist of fine intermetallic compounds with the size of˜0.1μm dispersed in the matrix. No change in hardness is observed for both the flakes and P/M materials isochronally annealed at temperatures below 573K. The microstructures of flakes and P/M materials exhibited high thermal stability against annealing at temperatures below 573K. The tensile strength of the P/M materials is higher than 350MPa with elongation higher than 15% at room temperature. Among the alloys, the Fe-bearing alloy has the highest tensile strength of 445MPa at room temperature, 346MPa at 473K and 216 MPa at 573K. The material with addition of Si has the lowest strength at all temperatures.