Unified description of the softening behavior of beta-metastable and alpha plus beta titanium alloys during hot deformation

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:651

Article

Poletti, Cecilia¹  Germain, Lionel^2,3  Warchomicka, Fernando¹  Dikovits, Martina¹  Mitsche, Stefan⁴ 

[1] Graz Univ Technol, Inst Mat Sci & Welding, A-8010 Graz, Austria

[2] Univ Lorraine, CNRS, Lab Etud Microstruct & Mecan Mat LEM3, UMR 7239, F-57045 Metz, France

[3] Univ Lorraine, Lab Excellence Design Alloy Met Llow mAss Struct, F-57045 Metz, France

[4] Graz Univ Technol, Inst Electron Microscopy & Nanoanal FELMI, A-8010 Graz, Austria

关键词: Titanium alloys;    Hot deformation;    Parent phase reconstruction;    Dynamic recovery;    Load partition;   

DOI  :  10.1016/j.msea.2015.10.109

来源: Elsevier

【 摘 要 】

In this work, we propose a unified description of the softening behavior of a beta metastable alloy and Ti6Al4V alloy. In the first part we provide sound evidence that the hot deformation of Ti6Al4V of the beta phase above and below the beta transus temperature takes place solely by dynamic recovery at moderate strains, similarly to the behavior of the Ti5Al5Mo5V3Cr1Zr near-beta alloy. This study was possible due to the combination of the fast cooling rates achieved after controlled hot deformation and the reconstruction of the parent beta phase from electron backscattered diffraction measurements of the frozen alpha phase by using an innovative developed algorithm. The dynamic recovery as a common dynamic restoration behavior for Ti6Al4V and Ti5Al5Mo5V3Cr1Zr is described mathematically with a Derby type relationship of the subgrain size and the stress of the beta phase. A rule of mixture allows the determination of the load partition between the two allotropic phases. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free