Mechanical Properties of Ti–6Al–4V Titanium Alloy with Submicrocrystalline Structure Produced by Multiaxial Forging

Abstract:

A comparative investigation of mechanical properties of Ti–6Al–4V titanium alloy with coarse-grained (400 m), microcrystalline (10 µm) and submicrocrystalline (0.4 µm) structures in the temperature range 20–500°C has been carried out. The submicrocrystalline structure was obtained by multiaxial isothermal forging. The alloys with the coarse-grained and microcrystalline structures were used in a heat-strengthened condition. The microstructure refinement increases both the strength and fatigue limit of the alloy at room temperature by about 20%. The strength of the submicrocrystalline alloy is higher than that of the microcrystalline alloy in the range 20 - 400°C. Long-term strength of the submicrocrystalline specimens below 300°C is also considerably higher than that of the other conditions. However, the creep strength of the submicrocrystalline alloy is slightly lower than that of the heat-strengthened microcrystalline alloy already at 250°C. The impact toughness in submicrocrystalline state is lower especially in the samples with introduced cracks. Additional surface modification of submicrocrystalline alloy by ion implantation gives a considerable increase in the fatigue limit. Advantages of practical application of submicrocrystalline titanium alloys produced by multiaxial isothermal forging have been evaluated.

• Periodical: Materials Science Forum (Volumes 584-586)
• Pages: 783-788
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.584-586.783
• Online since: June 2008
• Authors: Gennady A. Salishchev, Sergey V. Zherebtsov, Svetlana Malysheva, A. Smyslov, E. Saphin, N. Izmaylova
• Keywords: Creep, Ductile, Fatigue, Impact Toughness, Ion Implantation, Long-Time Strength, Mechanical Property, Multiaxial Forging, Strength, Submicrocrystalline Structure, TiAl

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