2024铝合金触变成形组织的不均匀性  

Microstructure Inhomogeneity of 2024 Aluminum Alloy Prepard by Thixotropic Forging

作　　者：周鹏[1] 纪兴华[2] 魏斌[3] 

机构地区：[1]枣庄科技职业学院机械工程系 [2]莱芜职业技术学院 [3]哈尔滨工业大学(威海)材料科学与工程学院

出　　处：《特种铸造及有色合金》2014年第9期921-924,共4页Special Casting & Nonferrous Alloys

摘　　要：采用再结晶与重熔法制备了2024铝合金半固态坯料,进行了某端盖的触变挤压铸造成形,研究了其组织与成分的不均匀分布以及制坯工艺参数对不均匀分布的影响。结果表明,挤压铸造件的中心位置液相凝固组织比较少,法兰位置则有较多的液相聚集,容易出现缩孔和微裂纹缺陷,同时越靠近法兰位置,微观组织的成分偏析程度越大,较小晶粒的坯料有利于缓解固液偏析现象。Semi-solid 2024 aluminum alloy billets were prepared by conventional RAP route（recrystallization and remelting）,and a cap parts were produced with the semisolid billets by thixoforging.The inhomogeneity of microstructure and composition as well as processing parameters of billet prepared were analyzed.The results show that the microstructure solidified from liquid phase is relatively minor at the center of billet,and liquid phase deposition at the flange region is major,resulting in shrinkage defects and micro-cracks.The composition segregation exhibits serious increasingly near to the flange region,and the segregation can be reduced with in the crostructure with fine grains.

关 键 词：2024铝合金 再结晶与重熔法 触变挤压铸造 组织不均匀 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG292[金属学及工艺—金属材料]