TiAl＋Ca合金断裂及变形亚结构研究

来源期刊：中南大学学报(自然科学版)1996年第6期

论文作者：曹鹏 贺跃辉 黄伯云

文章页码：703 - 706

关键词：TiAl基合金; 合金化; 断裂; 位错

Key words：TiAl-based alloys; alloying; fracture; dislocation

摘    要：运用SEM和TEM等分析手段研究了TiAl+Ca三元合金的室温断裂行为和变形亚结构.结果表明,少量Ca的添加可以大幅度提高Ti－34%Al合金的室温力学性能.合金断裂时不再表现为单纯的穿晶解理断裂而在γ单相中出现了河流状的解理纹,断口上还出现较多的撕裂梭;TEM分析表明,Ca的添加有助于1/2＜110]正常位错的启动;Ti－34%Al－1.0%Ca合金压缩变形时产生大量的位错环,当Ca含量达到2.0%时,在γ相中出现了由于位错分解而产生的层错.

Abstract: The fracture behaviors and deformation substructures of TiAl+Ca alloy were investigated using SEM and TEM. The results show small Ca additions to Ti-34%Al can improve remarkedly its mechanical properties at ambient temperature. The fracture mode is a mixed mode, including transgranular cleavage and "river" pattern in gamma single phase. A lot of tear ridges can be found in the fractured surfaces. TEM results indicate Ca additions can enhance the activity of ordinary unit dislocation 1/2 <110]. Dislocation loops in Ti-34%Al-1.0%Ca alloy and stack faults resulting from superdislocation dissociation in Ti-34%Al-2.0%Ca alloy, were observed.