Microstructure Evolution and Microhardness Analysis of Metastable Beta Titanium Alloy Ti-15V-3Cr-3Al-3Sn Consolidated Using Equal-Channel Angular Pressing from Machining Chips


Machining chips of Ti-15V-3Cr-3Al-3Sn metastable beta titanium alloy were consolidated using back pressure-assisted equal-channel angular pressing (BP-ECAP) using different processing conditions. Near fully dense specimens were obtained after multiple passes done at 500 °C with the aid of different back pressures. SEM and TEM observations show that ECAP resulted in a homogeneous formation of ultrafine equiaxed α grains (~ 180 nm) in the β matrix, due to the generation of an extensive amount of dislocations, vacancies and sub-grain boundaries during ECAP. Most of these α grains showed a random orientation with the β matrix. In addition, the observed grain refinement, increase in dislocation density and age hardening caused by this process resulted in a significant microhardness enhancement in the obtained parts. The microhardness homogeneity was improved as the processing temperature and the number of ECAP passes were increased.

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The authors are greatly indebted to Dr Riaz Muhammad and Dr Anish Roy from School of Mechanical and Manufacturing Engineering in Loughborough University for providing machining chips. The authors also acknowledge Dr Zhaoxia Zhou and Mr Scott Doak in Loughborough Materials Characterization Centre (LMCC) for their help in TEM analysis. The authors are grateful to the Nature Science Foundation of Guangdong (Grant No. 2018A030313127), the Guangdong Academy of Sciences Project and Development (Grant No. 2018GDASCX-0961), Guangzhou Science and Technology Project (201906040007).

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Shi, Q., Tse, Y.Y. & Higginson, R.L. Microstructure Evolution and Microhardness Analysis of Metastable Beta Titanium Alloy Ti-15V-3Cr-3Al-3Sn Consolidated Using Equal-Channel Angular Pressing from Machining Chips. J. of Materi Eng and Perform 29, 4142–4153 (2020). https://doi.org/10.1007/s11665-020-04913-8

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  • consolidation
  • equal-channel angular pressing
  • precipitation
  • Ti-15V-3Cr-3Al-3Sn
  • ultrafine-grained materials