消失模铸造重型汽车ZL101A变速箱壳体的缺陷分析

Defects Analysis of Aluminum Alloy Gear Box Housing for Heavy Duty Truck in Lost Foam Casting

采用可发性聚苯乙烯泡沫材料(EPS)来制作重型汽车变速箱壳体模型和浇注系统模型簇,用干石英砂逐层雨淋式填砂紧实造型,整个造型过程无需对铸型抽取负压。选用经过精炼和变质处理后的液态ZL101A铝合金在常压下浇注成形,获得了形状完整和力学性能符合要求的铸件。借助能谱仪对工艺试验过程中铸件表面出现的皱皮﹑铸件皮下浅层夹杂和内部深层夹杂缺陷分别进行了元素组成分析。

Product model for heavy duty truck gearbox housing and model cluster for gating system with bottom diversion continuous side ingate were made of expandable polystyrene EPS. After dipping and drying coating, the model cluster was put into a single flask, then filled with a dry quartz sand by layer sprinkling with negative pressure free in the whole molding compaction process. Liquid refined and mod- ified ZLIO1A alloy was poured into the pattern cluster at atmospheric pressure, and the gearbox with qualified appearance and mechanical properties was produced Successfully. By means of spectrum instru- ment, surface wrinkled, subsurface shallow inclusion and deep inclusion were analyzed. In addition, the three-dimensional morphology and elemental composition have been analyzed. Finally, the optimization process of EPC was put forward.