Cost-Effective Production of High-Property Titanium Alloy from Powder

Abstract:

Blended Elemental Powder Metallurgy is a very attractive method for producing titanium alloys, which can be formed near net shape and have freedom in composition selection. However applications are still limited due to affordability. In this paper, we will discuss a possible cost-effective route, combining vacuum sintering, extrusion, and heat treatment, to produce titanium alloys with similar or better mechanical properties than that of ingot metallurgy titanium alloys. The as-processed material with an oxygen content of 0.34 ± 0.005 wt.% was subjected to heat treatments such as β annealing plus ageing and α+β annealing without ageing to attain a typical lamellar/Widmanstätten/basketweave type structure with a large variation in terms of the microstructural features such as grain size, colony size, inter-lamellar spacing, thickness of grain boundary α, and size of individual lamellar. From mechanical property data attained here, it was apparent that annealing in high α-β region gave a much better combination of mechanical properties: yield strength (860-902 MPa), ultimate tensile strength (1060-1084 MPa) and ductility/plastic strain (11.5-13.6%). The hardness values of heat treated material varied between 346-376 Vickers hardness (36.8-44.5 Rockwell hardness).

• Periodical: Materials Science Forum (Volume 941)
• Pages: 1088-1094
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.1088
• Online since: December 2018
• Authors: Ajit Pal Singh, Fei Yang*, Rob Torrens, Brian Gabbitas, Leandro Bolzoni
• Keywords: Heat Treatment, Hot Processing, Mechanical Properties, Microstructures, Powder Metallurgy, Titanium Alloy

References

[1] M.J. Donachie, Titanium: A Technical Guide, 2nd ed., ASM International, Materials Park, OH, (2000).

[2] H. Chandler, Heat Treater's Guide: Practices and Procedures for Nonferrous Alloys, ASM International, Materials Park, OH, (1996).

[3] R.R. Boyer, G. Welsch, E.W. Collings, Materials Properties Handbook: Titanium Alloys, ASM International, Materials Park, OH, (1994).

[4] A.P. Singh, F. Yang, R. Torrens, B. Gabbitas, Solution treatment of Ti-6Al-4V alloy produced by consolidating blended powder mixture using a powder compact extrusion route, Materials Science and Engineering: A 712 (2018) 157-165.

DOI: 10.1016/j.msea.2017.11.098

[5] ASM Aerospace Specification Metals, Titanium Ti-6Al-4V (Grade 5), Annealed. <http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTP641>, n.d. (accessed 4 November.2015).

[6] S. Zherebtsov, E. Kudryavtsev, S. Kostjuchenko, S. Malysheva, G. Salishchev, Strength and ductility-related properties of ultrafine grained two-phase titanium alloy produced by warm multiaxial forging, Materials Science and Engineering A - Structural Materials Properties Microstructure and Processing 536 (2012) 190-196.

DOI: 10.1016/j.msea.2011.12.102

[7] R.W. Armstron, Influence of polycrystal grain size on several mechanical properties of materials, Metallurgical Transactions 1(5) (1970) 1169-1176.

DOI: 10.1007/bf02900227

[8] G. Lütjering, Influence of processing on microstructure and mechanical properties of (α+ β) titanium alloys, Materials Science and Engineering A 243(1) (1998) 32-45.

DOI: 10.1016/s0921-5093(97)00778-8

[9] X.H. Shi, W.D. Zeng, Y. Sun, Y.F. Han, Y.Q. Zhao, P. Guo, Microstructure-tensile properties correlation for the Ti-6Al-4V titanium alloy, Journal of Materials Engineering and Performance 24(4) (2015) 1754-1762.

DOI: 10.1007/s11665-015-1437-x

[10] D. Eylon, F.H. Froes, S. Abkowitz, Titanium powder metallurgy alloys and composites, in: P.W. Lee, B.L. Ferguson (Eds.), Powder Metal Technologies and Applications (ASM Metals Handbook), ASM International, Materials Park, OH, 1998, pp.2192-2231.

[11] D.J. McEldowney, S. Tamirisakandala, D.B. Miracle, Heat-treatment effects on the microstructure and tensile properties of powder metallurgy Ti-6Al-4V alloys modified with boron, Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. 41A(4) (2010) 1003-1015.

DOI: 10.1007/s11661-009-0157-y

[12] J.D.K. Rivard, C.A. Blue, D.C. Harper, J.O. Kiggans, P.A. Menchhofer, J.R. Mayotte, L. Jacobsen, D. Kogut, The thermomechanical processing of titanium and Ti-6Al-4V thin gage sheet and plate, JOM: Journal of the Minerals, Metals and Materials Society 57(11) (2005) 58-61.

DOI: 10.1007/s11837-005-0029-x

[13] A.P. Singh, B. Gabbitas, F. Yang, R. Torrens, A. Mukhtar, Effect of Pre-Consolidation Methods and Oxygen on the mechanical Properties of As-Extruded Ti-6Al-4V Alloy Rod, Proceedings of the 13th World Conference on Titanium, John Wiley & Sons, Inc.2016, pp.1347-1354.

DOI: 10.1002/9781119296126.ch228

[14] L.W. Meyer, L. Krüger, K. Sommer, T. Halle, M. Hockauf, Dynamic strength and failure behavior of titanium alloy Ti-6Al-4V for a variation of heat treatments, Mechanics of Time-Dependent Materials 12(3) (2008) 237-247.

DOI: 10.1007/s11043-008-9060-y