A low-cost and high-strength Ti-Al-Fe-based cast titanium alloy for structural applications

摘要

A cost-effective alpha-beta titanium casting alloy, Ti-6Al-5Fe-0.05B-0.05C,(1) has been designed using Calculation of Phase Diagrams (CALPHAD) method and the workhorse alloy Ti-6Al-4 V as a baseline. The substitution of iron for vanadium significantly reduces the raw material cost and improves the castability compared to the Ti-6Al-4 V alloy. The very fine alpha phase in the microstructure of the new alloy, likely due to Fe partitioning, provides exceptionally high strength (1023 MPa yield strength and 1136 MPa ultimate tensile strength) and reasonable ductility (3.71% elongation) for structural applications. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.