INFLUENCE OF LIQUID-PHASE INCLUSION ON HIGH-TEMPERATURE DEFORMATION-BEHAVIOR IN AL-BI ALLOYS

Tensile properties of an Al-3.4mass% Bi alloy up to 700 K were studied to understand the effects of the liquid Bi phase. Strain-rate sensiti vity near the melting point of Bi was found to take values in a range of 0.17-0.31. Elongation showed a maximum value slightly above the mel ting temperature, indicating that the liquid phase could enhance tensi le elongation in the AI-Bi alloy. Above the melting temperature, the d islocation density was found to decrease and the increment of the cavi ty volume fraction with strain slowed down in comparison to the result s below the melting temperature. The increase of the tensile elongatio n was attributed to an efficient stress accommodation mechanism provid ed by the liquid phase. (C) 1997 Elsevier Science S.A.