マグネシウム特集号 ＴｉＣ粒子強化マグネシウム複合材料における粒子分散挙動および機械的性質に及ぼす合金元素の影響

Abstract

TiC particulate reinforced magnesium matrix composites were fabricated by melt stirring method. The effect of alloying elements on TiC particulate dispersion into molten magnesium and mechanical properties were investigated. The incorporation time is defined as the time required for dispersion of solid particles into molten metal. The incorporation time of TiC particles into molten pure magnesium was remarkably shorter and the particulate dispersion was more uniform than that of pure aluminum which was reported previously. The incorporation time was prolonged by the addition of Al, Bi, Ca, Ce, Cu, Pb, Sn or Zn. The tensile strength increased and elongation decreased by the addition of Cu or Sn into the matrices and composites. Although, the tensile strength of the matrices and composites increased by alloying with Ca or Ce, the maximum elongation was observed at a content of about 1% for the matrices. By alloying with Zn, the tensile strength increased for the matrices and composites, but the elongation of the matrices increased. The pure magnesium and its alloy matrix composites reinforced with 20vol%TiC have the tensile strength of about 400MPa. This value is compared with the tensile strength of SiC whisker reinforced magnesium matrix composites fabricated by liquid infiltration method at the same volume fraction. Therefore, the melt stirring method which has the advantages of simple process is considered to be efficient in fabricating magnesium matrix composites.