MECHANICAL PROPERTIES OF DIRECTIONALLY-SOLIDIFIED Ni₃Al CONTAINING BORON AND CARBON

来源期刊：中国有色金属学报(英文版)1997年第2期

论文作者：Zhang Yun Lin Dongliang

文章页码：87 - 91

Key words：intermetallics; Ni₃Al; stoichiometry; solid solution alloying; mechanical property

Abstract: The effect of alloying element of boron or carbon on the yield stress of directionally solidified Ni ₃Al has been studied by tensile tests in a temperature range of 123～1 223 K. First, the temperature dependence of the yield stress affected by the additives was evaluated. The measured activation energy for the thermally activated process which results in the anomalous mechanical behavior in Ni ₃Al decreases for each elemental addition. And this decrement becomes weaker when the ratio of Al/Ni for Ni ₃Al increases. Secondly, the yield stress at 123 K, taken as a measure of the degree of solid solution strengthening, increases linearly with boron or carbon content. The solid solution strengthening capacity arising from boron addition becomes stronger in stoichiometric sequence Ni ₇₆ Al ₂₄ 75 Al ₂₅ 74 Al ₂₆ . Finally, the mechanism for the anomalous mechanical behavior in Ni ₃Al affected by the additives was also discussed.