【摘要】 研究了Ni51.8Al48.2、Ni50.7Al49.2Zr0.1和Ni51.7Al48.16B0.14三种成分金属间化合物的多晶铸造组织。结果表明，NiAl由于热传导性好、凝固迅速，获得的均为完全等轴晶组织，并且易形成疏松;铸造表面的Si、O高含量层的厚度一般为20μm;三种金属间化合物的显微硬度按Ni50.7Al49.2Zr0.1、Ni51.8Al48.2、Ni51.7Al48.16B0.14的顺序增加;Zr、B对NiAl的断裂行为没有显著影响，三种化合物均以穿晶解理方式断裂。更多还原

【Abstract】 An investigation of cast structures of three kinds of nickel - alumina intermetallics(Ni_{51 .8}Al_48.2, Ni_50.7Al_49.2Zr_{0. 1} and Ni_{51 .7}Al_{48. 16}B_0.14 was undertaken. The results showed that complete equiaxed crystal structures were acquired in the casting process, accompanied by the existence of lots of porosity. The reason for this was that high thermal conductivity of NiAl promoted the quick finish of solidification of NiAl melt. The thickness of layer with high Si and O concentration on cast surface was about 20 μm. The hardness of three intermetallics decreased according to the sequence of Ni_{51 .7}Al_{48. 16}B_0.14, Ni_{51 .8}Al_48.2, Ni_50.7Al_49.2Zr_{0. 1}. There were no effects of Zr and B on the fracture mode of NiAl. The fracture of all three intermetallics took place in transgranular and cleavage mode.更多还原