%0 Journal Article %A Shishuang LIU %A Yi ZHOU %A Juan LI %A Jingxia CAO %A Jianming CAI %A Xu HUANG %A Shenglong DAI %T Microstructure evolution and mechanical behavior of Ti-22Al-23Nb-1Mo-1Zr alloy ring forging %D 2022 %R 10.11868/j.issn.1001-4381.2021.000590 %J Journal of Materials Engineering %P 147-155 %V 50 %N 4 %X

The microstructure evolution, tensile properties and fracture behavior of five-element Ti2AlNb alloy Ti-22Al-23Nb-1Mo-1Zr (atom fraction/%) ring forging at different solution temperatures of 850, 880, 900 ℃ and 750 ℃ aging treatment (AT) were studied by scanning electron microscope (SEM), transmission electron microscopy (TEM) and mechanical testing machines. The results show that with the increase of solution temperature, the fine lamellar O phase is more solid-dissolved into the B2 phase matrix, the coarse lamellar O phase gradually becomes coarser and the volume fraction of O phase decreases after solution treatment (ST). After ST+AT, a very small amount of fine lamellar O phase precipitates from the B2 phase matrix at a higher solution temperature, coarse lamellar O phase is coarsened, the volume fraction of O phase tends to be the same. The tensile strength of the alloy decreases, while the ductility increases with the increase of solution temperature. The tensile fracture morphology is a quasi cleavage characteristic of typical cleavage and dimple mixed fracture. There are microcracks, slip characteristics and the bending O phase elongated along tensile direction in the longitudinal fracture. Dislocations distribute along the B2/O phase boundary. The small size of the lamellar O phase can effectively reduce the dislocation slip distance, resulting in strong strengthening effect.

%U https://jme.biam.ac.cn/EN/10.11868/j.issn.1001-4381.2021.000590