高温合金晶粒细化概述

随着铸造合金尤其是铸造高温合金在工业领域内的广泛应用，多年来冶金工作者为了充分发挥合金的作用及改善合金的性能，对晶粒细化给予很大的关注，并采用了各种方法，如添加形核剂、快速冷却、工艺参数的控制、熔体在凝固过程中的机械振动和搅拌及精铸壳内表面涂层等。“ＦＧＰ”细化工艺、Ｍｉｃｒｏｃａｓｔ－Ｘ专利、Ｇｒａｉｎｅｘ专利和用ＣｏＯ＋Ａｌ２Ｏ３在精铸壳内表面涂层等已被工业采用。虽然孕育剂的添加是一种有效、简单和实用的晶粒细化方法，但直至目前，因为各种因素的限制尚未发现一种令人满意的高温合金细化添加剂。因此，靠加孕育剂细化高温合金晶粒是很困难的，目前这方面的研究仍在进行。

Summary of Grain Refining of Superalloys

With cast alloys, especially cast superalloys, being widely used in the industry field for many years, metallurgical workers have paid great attention to the grain refining in order to give full play to the function of the alloys and improve their properties.Various kinds of methods were adopted, such as addition of nuclei forming inoculants;rapidly cooling;control of the procedure parameters;mechanical vibration and agitation of the melt during solidification, and coating on the inner surface of the investment casting mould etc. For instance, FGP(fine grain procedure),Microcast-X patent, Grainex patent,and coating with CoO +Al2O3 on the inner surface of the investment casting mould etc.have been introduced into industry.Although the addition of inoculants is efficient, simple, and practical for the grain refinement of alloys, none of the satisfied inoculants for grain refinement of superalloys has been found because of the limitation of various factors. Therefore it is very difficult to refine the grains of superalloys by the addition of inoculants.At the moment,the studies are still underway.