Elongation of Al casting can be more than 10% by means of counter pressure casting,in which alloy composition and impurities contents are closely controled, and heat treating procedure is adjusted.

• 采用差压铸造压力场铸造工艺，对合金成分和杂质含量作严格控制，加上热处理工艺的调整，可以使铝铸件的延伸率＞10%25。