一、对表面晶粒细化 机理的验证 当前,国内外高温合金铸件进行表面晶粒细化所用的形核剂主要是铝酸钴和硅酸钴,其细化作用的机理,有以下几种观点,我们一一作了验证。 1.铝酸钴等形核剂与合金初生基体相之间“结构相似、大小相当”。 高温合金的基体相是γ固溶体,它们的晶体结构是面心立方,晶格常数是3.56—3.58A左右。我们按照CoO—Al_2O_3及CoO—SiO_2相图 First, the surface grain refinement mechanism validation At present, the domestic and foreign high-temperature alloy casting surface grain nucleating agent used are mainly cobalt aluminate and cobalt silicate, the refining mechanism of action, the following Point of view, we have verified. 1. The cobalt aluminate and other nucleating agents and alloy primary matrix phase “similar structure, the size is quite.” Superalloy matrix phase is γ solid solution, their crystal structure is face-centered cubic, the lattice constant is about 3.56-3.58A. We follow the CoO-Al 2 O 3 and CoO-SiO 2 phase diagrams