锌铝系合金铸造时出现反常的底部缩孔，而用一般上置式冒口对此类缩孔的补缩效果甚微。

There is abnormal bottom shrinkage in Zn Al alloy castings and top riser has little effect on them.

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锌铝系合金铸造时出现反常的底部缩孔，而用一般上置式冒口对此类缩孔的补缩效果甚微。

There is abnormal bottom shrinkage in Zn Al alloy castings and top riser has little effect on them.

youdao