共晶、亚共晶铝硅合金加钠变质处理,对合金的性能影响很大。检验变质效果的最可靠的方法是观察变质前后显微组织的变化,但这种方法不能作为炉前工艺检验的手段。目前,国内采用的炉前控制方法是观察、比较工艺试样的断口形貌,这种方法要求有丰富的现场经验,不同观察者往往会得出不同的结果,迄今尚未制定统一的标准。近年 Eutectic, hypoeutectic Al-Si alloy plus sodium metamorphic treatment, a great impact on the performance of the alloy. The most reliable way to check the effect of metamorphism is to observe the changes of the microstructure before and after the metamorphism, but this method can not be used as the test method of furnace beforehand. At present, the domestic method of furnace control is to observe and compare the fracture morphology of the sample. This method requires rich field experience. Different observers often produce different results. So far, no unified standard has been formulated. in recent years