本研究探討微量元素(鈹、鋯與鈧)對357合金(Al-7Si-0.6Mg(wt%) 機械、腐蝕與磨耗性質之影響，結果顯示，鑄態下，微量鈹和鈧可以細化共晶矽，並將針狀富鐵相轉變為結球狀和文字型富鐵相，且鈧可使合金縮孔減少;而鋯並無法改良共晶矽和富鐵相，且會產生棒狀含鋯介金屬化合物。T6熱處理後共晶矽顆粒皆粗化，添加鈹和鋯之合金富鐵相則沒有顯著改變，而添加鈧之合金的富鐵相會從文字型轉變成結球型富鐵相。 T6態下，含鈧之合金具有最佳拉伸品質指標，但含微量鋯之合金雖具有最高抗拉強度，但品質指標較低。 未添加微量元素的357合金經磨耗後，磨耗表面剝落顯著且有微裂縫的產生，但含鈹和鈧之合金擁有較好的抗磨耗性質，而添加鋯之合金因僅改變合金硬度，表面仍有部分剝落，但抗磨耗性質仍較357合金為佳。 含微量鈹與鈧之合金擁有較佳之抗腐蝕性質，尤其含鈧合金有效減少孔蝕、腐蝕面積，抗蝕效果更為明顯。 電位提高時，未添加微量元素、添加鈹與鋯等三種合金皆會產生嚴重的腐蝕磨耗現象，而含鈧的合金於T6態+300mV(vs OCP)時，擁有最佳的抗腐蝕磨耗性質。 ;The principal aim of this research is to evaluate the effect of minor additions of beryllium zirconium,and scandium on the mechanical , corrosion , and sliding wear property of 357 alloys (Al-7wt%Si-0.6wt%Mg).The results indicated that addition of beryllium and scandium in Al-7Si-0.6Mg alloys could reduce the sizes of eutectic silicon particles and make the shape of acicular iron-bearing phase transform into tiny globular or Chinese script iron-bearing phase. However,The zirconium has no effect. Moreover, the addition of scandium could reduce the interdendritic shrinkage. During T6 heat treatment the iron-bearing phase of addition beryllium didn’t have obvious difference. However the addition scandium would make Chinese iron-bearing phase transform into globular iron-bearing phase. And the addition scandium have highest elongation and quality index. During sliding wear test, the wear surface of 357 alloy had obvious grooves and micro-crack. Addition beryllium and scandium could reduce grooves and increase wear property. Addition beryllium and scandium had better corrosion resistance, especially the addition scandium that could efficiently reduce the pitting corrosion and corrosion area. As the potential increased, the 357 alloy and the addition beryllium had serious wear-corrosion. However the addition scandium had best wear-corrosion resistance under 300mV and T6 condition .
