镧铈混合稀土变质Al-28%Si活塞合金  

Modification of Al-28%Si Piston Alloy with La-Ce Mixed Rare Earths

作　　者：胡慧芳[1] 李华基[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044

出　　处：《热加工工艺》2010年第9期66-68,共3页Hot Working Technology

摘　　要：采用镧铈型混合稀土对过共晶Al-28%Si活塞合金进行了变质处理,对其显微组织和力学性能进行了研究。结果表明:与单一稀土铈变质相比较,镧铈型混合稀土对该合金具有较好的变质效果,初晶硅的尺寸基本保持在20μm左右,且尖角大多钝化呈团球化状,共晶硅呈短杆状均匀分布;合金经过混合稀土变质后,晶界处产生复杂化合物组织起到了弥散强化作用,使其综合力学性能明显提高,尤其是高温强度的显著提高,已完全满足活塞合金在使用性能上对高温强度的要求。La-Ce mixed rare earths were used to modify hypereutectic Al-28%Si pistton alloy,the microstructure and mechanical property were studied.The results show that La-Ce mixed rare earths have the nicer effect of modification,the size of primary silion in casting is about 20 μm,the figure of primary silion is round.Meanwhile,the eutectic sicilon is all well-proportioned distributing.The hypereutectic Al-28%Si alloy with addition of La-Ce mixed rare earths is appropriate,a number of hard dispersed complex compounds are formed in the grain boundaries.All these hard dispersed complex compounds have the action of dispersion strengthening,so the comprehensive mechanical properties of the alloy improve,especially,its high temperature mechanical properties obviously improve,which can meet the request of piston alloy for high temperature properties.

关 键 词：混合稀土 Al-28%Si活塞合金 显微组织 综合力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG113.25[金属学及工艺—金属材料]