NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Mechanisms of kinetically-induced fine secondary α-Ti phase formation in a novel as-cast titanium alloy
Published
Author(s)
Zhi Liang, Xuejun Huang, Jiashi Miao, Fan Zhang, James Williams, Alan Luo
Abstract
The phase transformation mechanisms from the body-centered cubic (BCC) β matrix to fine hexagonal close packed (HCP) α precipitates in an as-cast α-β titanium alloy, Ti-6Al-5Fe-0.05B-0.05C (all in mass %), were investigated experimentally and computationally using CALculation of PHAse Diagram (CALPHAD)-based thermodynamic and kinetic models. The discrete distribution of α precipitates was observed in the as-cast alloy with evidence of strong Fe partitioning. Two main size groups of α precipitates and the Fe partitioning were observed by scanning electron microscopy, scanning transmission electron microscopy, and synchrotron-based small-angle X-ray scattering. The hypothesis of Fe-partitioning driven α precipitate nucleation and growth was validated by precipitation simulation using TC-PRISMA with customized thermodynamic and kinetic descriptions. These results suggested a new titanium alloy design route involving high mobility elements (enhancing fine secondary α precipitates) and demonstrated the capability of CALPHAD-based modeling in titanium alloy design.
Citation
Metallurgical Transactions A-Physical Metallurgy and Materials Science
Liang, Z.
, Huang, X.
, Miao, J.
, Zhang, F.
, Williams, J.
and Luo, A.
(2022),
Mechanisms of kinetically-induced fine secondary α-Ti phase formation in a novel as-cast titanium alloy, Metallurgical Transactions A-Physical Metallurgy and Materials Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933753
(Accessed October 11, 2025)