Founding Research Journal

Founding Research Journal

The Evaluation of Thermomechanical and Heat Treatment Parameters on the ‎Microstructure and Tensile Properties of Ti-6Al-2Sn-4Zr-2Mo-0.08Si Alloy

Document Type : Original Research Article

Authors
1 Associate Professor, Faculty of Materials and Manufacturing Technologies, Malek Ashtar ‎University of Technology, Tehran, Iran.‎
2 Professor, Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of ‎Technology, Tehran, Iran.‎
3 M.Sc. Student, Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran
10.22034/frj.2024.402919.1179
Abstract
This research aims to study the effect of the cooling environment after secondary rolling and the annealing temperature on the microstructure and tensile properties of the near alpha Ti-6242S alloy. The produced ingot was homogenized and hot rolled at 1150oC. Then, the transit temperature of alpha to the beta of the alloy was determined as 1000±5oC via heat treatment and hot torsion test. Subsequently, the strips were secondary hot rolled at 940oC and cooled at water and air. Then, they were solution annealed for 1 hour at 940 and 970oC, and water quenched and aged. Afterwards, the microstructure was studied and the tensile test was performed at 25 and 480oC. Results showed that the specimens with the same cooling environment annealed at 970oC as compared with the ones annealed at 940oC, have the microstructure with more rounded and lower volume fraction of primary alpha phase and wider secondary alpha phase results to the achievement of higher strength and ductility. Besides, the increase in strength of the specimens cooled in air compared to the ones cooled in water after rolling is related to the higher volume fraction of the alpha phase leading to a decrease in ductility.
Keywords
Subjects

[1] Lütjering G., Williams J. C., Titanium, Springer, First Edition, 2003.
[2] Srivatsan T., Al-Hajri M., Petraroli M., Derreberry B., Lam P., The fracture behavior of a Ti-6242 alloy deformed in bending fatigue, Materials Science and Engineering A, 2002, 334, 327-333.
[3] Hörnqvist M., Mänsson T., Fatigue crack growth in Ti-6242 under elasto-plastic loading conditions, Procedia Engineering, 2010, 2, 223-229.
[4] Campbell J.F., Manufacturing technology for aerospace structural materials: Elsevier, First Edition, 2011.
[5] Leyens C., Peters M., Titanium and titanium alloys, Wiley‐VCH Verlag, First Edition, 2003.
[6] Lütjering G., Williams J., Gysler A., Microstructure and mechanical properties of titanium alloys, Microstructure and Properties of Materials, 2000, 2, 1-74.
[7] Mitchell B. S., An introduction to materials engineering and science for chemical and materials engineers, John Wiley & Sons, First Edition, 2004.
[8] Semiatin S.L., An overview of the thermomechanical processing of α/β titanium alloys: current status and future research opportunities, Metallurgical and Materials Transactions A, 2020, 51, 2593–2625.
[9] Semiatin S., Thomas J., Dadras P., Processing-microstructure relationships for Ti-6Al-2Sn-4Zr-2Mo-0.1 Si, Metallurgical Transactions A, 1998, 14 2363-2374.
[10] Dieter G. E., Kuhn H. A., Semiatin S. L., Handbook of workability and process design, ASM International, First Edition, 2003.
[11] Welsch G., Boyer R., Collings E.W., Materials Properties handbook: Titanium alloys, ASM International, First Edition, 1993.
[12] Roy S., Tungala V., Suwas S., Effect of Hypoeutectic boron addition on the β transus of Ti-6Al-4V alloy, Metallurgical and Materials Transactions A, 2011, 42, 2535-2541.
[13] Fields J.D.S., Backofen W.A., Determination of strain-hardening characteristics by torsion testing, American Society for Testing and Materials Proceedings, 1957, 57, 1259-1272.
[14] Prasad Y. V. R. K., Sasidhara S., Hot working guide: A Compendium of processing maps, ASM International, First Edition, 1997.
[15] Abbaschian R., Reed-Hill R., Physical metallurgy principles, Cengage Learning, Forth Edition, 2009.
[16] Dehghan-Manshadi A., Dippenaar R.J., Strain-induced phase transformation during thermo-mechanical processing of titanium alloys, Materials Science and Engineering A, 2012, 552, 451-456.
[18] McQuillan M., Phase transformations in titanium and its alloys, Metallurgical Reviews, 1963, 8, 41-104.
[19] Sha W., Malinov S., Titanium alloys: Modelling of microstructure, properties and applications, Elsevier, First Edition, 2009.
[20] Lin P., Zhou L., Xu P., et al. Enhanced strength of dual-phase Ti6242 alloy via a heterogeneous microstructure, Materials & Design, 2023, 230, 111972.
[21] Jia W., Zeng W., Yu H., Effect of aging on the tensile properties and microstructures of a near-alpha titanium alloy, Materials & Design, 2014, 58, 108-115.
[22] Donachie M.J., Titanium: A technical guide: ASM International, Second Edition, 2000.
Volume 7, Issue 1 - Serial Number 22
Spring and Summer
Spring 2023
Pages 45-55

  • Receive Date 18 June 2023
  • Revise Date 08 October 2023
  • Accept Date 10 March 2024