本文报道了铝当量为19-23at.-％的一系列铸造Ni_3Al基合金的显微组织和塑性及其与合金元素间关系的研究结果。表明,Hf、Ti和Zr显著地改变初生Ni_3Al(γ’)相的形态和分布并细化其尺寸,而Nb、W和Ta则不具有上述作用,在显微组织被细化的合金中,形成韧性的γ’-γ-γ’界面,消除了本质弱化的γ’-γ’脆性界面,初生相的尺寸可以控制在几十微米,表现出良好的塑性,尤其是中温塑性有较大改善。另外,组织细化的合金在无Cr时仍有可观的塑性,Cr对改善中温塑性有益,这可能是由于它改变合金中的γ相的数量和分布的结果。
Investigation was made of the ductility and microstructure of a series of castNi_3Al-basb alloys, containing alloying element corresponding to equivalent Al ranged 19--23at.-%, with relation to their alloying elements. An obvious improvement on morphology, dis-tribution, amount and size of primary Ni_3Al(γ') intermetallic compound was approached bysuch alloying elements as Hf, Ti, Zr, but no more by Nb, W, Ta. The formation of ductileγ'-γ-γ' boudary in the alloys with refined primary γ'-phase may eliminate the weakened na-ture of brittle γ'-γ' boundary, and reduce the size of primary γ'-phase to tens of μm. thus, theductility of the alloys, especially at intermediate temperature may be markedly improved. Inaddition, an alloy free from Cr is still significantly ductile, only its structure refined. Theavailability of Cr to improving the intermediate temperature ductility seems to be due to thechange of amount and distribution of γ-phase.
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