微量C，B对高铌TiAl合金显微组织与力学性能的影响

Influence of C and B Elements on Structures and Mechanical Properties for High Nb Containing TiAl Alloy

摘要:

采用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)等设备，以及拉伸和蠕变试验系统研究微量间隙元素C，B对高铌TiAl合金显微组织与力学性能的影响。微量B元素对高铌TiAl合金没有明显的强化作用，但是微量B元素在合金中以条状或点状的TiB2存在，TiB2细化了高铌TiAl合金原始片层团晶粒，对改善高铌TiAl合金片层组织的室温塑性有利。加微量C元素的高铌TiAl合金在长时间的蠕变过程中，大量Ti3AlC沉淀相的析出提高了高铌TiAl合金全片层组织蠕变抗力。

Abstract:

The influence of C and B micro-alloying elements on the microstructures and mechanical properties for high Nb containing TiAl alloy was systematically studied. The B micro-addition has a weak effect on the strengthening, but ribbon or dot shaped TiB2 forms at the lamellar colony boundaries and refines the original colony, which is beneficial to improve the room temperature ductility of high Nb containing TiAl alloy. The precipitation of a large amount of Ti3AlC raises the creep resistance during long time creep for high Nb containing TiAl alloy with micro-addition of C.