Deformation mechanism of fine structure and its quantitative relationship with quasi-static mechanical properties in near β-type Ti-4.5Mo-5.1Al-1.8Zr-1.1Sn-2.5Cr −2.9Zn alloy

Progress in Natural Science: Materials International

Xingwang Cheng¹  Haichao Gong¹  Qunbo Fan¹  Yu Gao²  Duoduo Wang³  Hong Yu³  Liu Yang³  Zhiming Zhou³  Xinjie Zhu³ 

[1] Beijing Institute of Technology Chongqing Innovation Center, Chongqing, 401135, China;Corresponding author.;National Key Laboratory of Science and Technology on Materials Under Shock and Impact, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China;

关键词: Deformation mechanism;    Fine structure;    Quantitative relationship;    Titanium alloy;   

DOI  :  

来源: DOAJ

【 摘 要 】

The deformation mechanism of the fine structure composed of primary α phase (αp) and acicular secondary α phase (αs) on quasi-static mechanical properties is still not very clear. The main controversy is focused on the role of αp in the mechanical behavior. In this paper, the microstructure of the heat-treated near β-type Ti-4.5Mo-5.1Al-1.8Zr-1.1Sn-2.5Cr-2.9Zn alloy after tensile tests was observed by transmission electron microscopy (TEM). And the results showed that in the slight deformation region the dislocations were accumulated at the intersection of αp and β matrix separated by αs, while only a few dislocations nucleated in β matrix. In the severe deformation region, a large quantity of dislocations in both αp and β matrix were observed. It can be inferred that αp deformed firstly and then activated the deformation of β matrix, that is, the thickness of αp and the inter-particle spacing of αs played a dominant role in the deformation process. The quantitative relationship between the yield strength and the microstructure parameters is consistent with this inference. By adjusting the solution treatment parameters and the subsequent aging treatment, three fine structures were obtained, and the corresponding mechanical properties were determined. Furthermore, the yield strength can be described by the mathematical model σy ​= ​756.4 ​+ ​135.6/hp1/2 +32.2/ds1/2, where hp and ds are the thickness of αp and the inter-particle spacing of αs, respectively.

【 授权许可】

Unknown