铸造铝硅合金中富铁相的彩色金相分析

富铁相为铝硅合金中有害的相．当合金中含铁量较少时．富铁相呈细针、片状脆性相．铝硅合金经过常规腐蚀处理后．其中的富铁相与共晶组织中的硅相从形态和色泽上难以分辨．从而影响组织鉴别．本文采用化学染色法将富铁相染成棕色，而硅相则不被染色，仍为灰白色，从而能够通过彩色金相分析的方法清晰地将富铁相与硅相区分开来．彩色金相分析方法操作简单．容易在生产实践中推广使用．

COLOR-METALLOGRAPHIC ANALYSIS OF THE IRON-RICH PHASE IN THE CAST ALUMINUM-SILICON ALLOY

The iron-rich phase is harmful to the aluminum-silicon alloy.It constitutes a kind of fine-needle-like or sheet-like brittle phase when the content of iron in the alloy is low.After routine corrosion treatment,it is difficult to distinguish the iron-rich phase from the silicon phase in eutectic organization by color and configuration,and the organization analysis of alloy can hardly be mode.In this paper,chemical coloration is used for altering the color of iron-rich phase to brown and keeping the silicon phase still gray.Results of coloration show that the color-metallographic analysis makes the iron-rich phase distinguished clearly from the silicon phase in the aluminum-silicon alloy.As the method of color-metallographic analysis is simple and practical,it is recommendable to be applied in industrial production.