Influence of rate of heating to aging temperature on precipitation hardening in a metastable β titanium alloyShow others and affiliations
2014 (English)In: Advanced Materials Research, ISSN 1022-6680, E-ISSN 1662-8985, Vol. 1025-1026, p. 445-450Article in journal (Refereed) Published
Abstract [en]
A comparison between slow heating to aging temperature and direct charging at aging temperature on the microstructure and mechanical properties obtained after the aging was established for the metastable beta (β) titanium alloy Ti-15V-3Cr-3Al-3Sn. The alloy was subjected to two single aging (SA) and two duplex aging (DA) conditions, with two heating rates to aging temperature: (i) low heating rate of 5 oC/min (ii) direct charging into a furnace heated to aging temperature. The microstructure analysis was carried out using Field Emission Scanning Electron Microscopy. Mechanical Testing was carried to evaluate Ultimate Tensile Strength (UTS), 0.2% Yield Strength (YS), % Elongation (%El.), % Reduction in area (%RA) and hardness. In the case of SA samples aged at 500 °C for 8 h and 500 °C for 10 h, heating rate of 5 °C/min to aging temperature resulted in a finer microstructure but did not help in achieving better strength-ductility combination compared to direct charging. Lower rate of heating allows enough dwell time in the temperature range 250-300 oC for pre-precipitation reaction to occur which aids in fine scale precipitation of alpha phase during aging. In the case of DA samples aged at 250 oC for 24 h followed by 500 oC for 8 h and 300 oC for 10 h followed by 500 oC for 10 h, no tangible difference between lower rate of heating and direct charging was observed in mechanical properties or microstructure. This is believed to be due to the pre-aging steps 250 oC/24 h or 300 oC/10h in the two DA treatments, which create finely distributed precursors thereby leaving no scope for the heating rate to play a role.
Place, publisher, year, edition, pages
Trans Tech Publications, 2014. Vol. 1025-1026, p. 445-450
Keywords [en]
Beta titanium alloy, Microstructure, Pre-precipitation, Single and duplex aging, Tensile properties, α phase precipitation, Age hardening, Alloys, Field emission microscopes, Hardness, Heating, Heating rate, Precipitation (chemical), Scanning electron microscopy, Tensile strength, Tensile testing, Titanium, Field emission scanning electron microscopy, Fine-scale precipitation, Metastable beta-titanium alloys, Microstructure analysis, Microstructure and mechanical properties, Phase precipitations, Ultimate tensile strength, Titanium alloys
National Category
Metallurgy and Metallic Materials
Identifiers
URN: urn:nbn:se:hj:diva-45674DOI: 10.4028/www.scientific.net/AMR.1025-1026.445Scopus ID: 2-s2.0-84913527732OAI: oai:DiVA.org:hj-45674DiVA, id: diva2:1345159
Conference
2014 International Conference on Advanced Materials, Structures and Mechanical Engineering, ICAMSME 2014, Incheon, South Korea
2019-08-232019-08-232021-06-04Bibliographically approved