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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。
The 2024 aluminum alloy semi-solid billet was prepared by recrystallization and remelting method. The thixo-extrusion die-forming of one end cap was carried out. The non-uniform distribution of the structure and composition and the influence of billet processing parameters on the non-uniform distribution were studied . The results show that there are few liquid phase solidified in the center of the squeeze castings and more liquid phase accumulates in the flange, which tends to cause shrinkage cavity and micro-crack defects. At the same time, the closer to the flange, the more segregation of microstructure The greater the degree, the smaller grain billet is conducive to ease the phenomenon of solid-liquid segregation.