作　　者： ; ; (张丽萍）; (刘睦坤）; (赵振华）; (陈增玉）;

机构地区： 哈尔滨东安汽车动力股份有限公司工艺技术部黑龙江哈尔滨150066

出　　处： 《应用科技》 2012年第6期84-88,共5页

摘　　要： 铸造Al-Si合金由于流动性好、组织致密等优点,使其在铸铝中的所占比重越来越高.AC4B合金基于其优点常用于浇铸476气缸盖,但在生产过程中却存在硬度偏低、机械加工性能不好等问题.文中根据铝合金的变质原理,通过添加Ti和Sr对铝合金进行变质处理,并与未变质铸件进行组织观察和硬度测试对比,结果表明变质后铸件α(Al)基体组织细化,Si相由变质前的长针状变成不规则粒状组织,硬度稳定提高到了70 HB以上,改善了加工性能,同时总结了变质的衰退规律. Due to its good fluidity and compact structure, cast Al-Si alloy posses a higher and higher proportion in cast aluminum alloys. AC4B alloy is usually used to cast 476 cylinder head based on its merits, but the problems such as low hardness and poor machining property often emerge in the production process. In this paper, modification of the aluminum alloy is performed by adding Ti and Sr into the ahoy according to the metamorphic principle, and then the modification treatment casting is compared to the un- treated one by microstructure observation and hardness test. The results show that after modification, the microstructure of the matrix of theα （Al） casting is refined, and the Si phase grows into an irregularly shaped granular structure from a needle-shaped structure. The hardness of the casting is steadily increased to more than 70 HB. The machining property of the casting is improved. The recession law of the modification is also summarized in this paper.

关 键 词： 气缸盖 变质处理 金相组织 硬度

领　　域： [金属学及工艺] [一般工业技术] [金属学及工艺]