Design, microstructure and mechanical properties of new Ti-based alloys
type: CreativeWork
description: In this PhD study, using the DV-Xα molecular orbital method three new series of TixFe- yTa, Ti-Fe-xNb and Ti-Nb-xFe alloys are designed for the first time. The alloys are then produced by cold crucible levitation technique. The influence of Ta, Fe and Nb contents on the phase transformation, β phase stability and microstructural evolution of the alloys are investigated. Additionally, the resulting mechanical properties of the alloys are evaluated and compared with those of the widely used biomaterials, i.e. CP-Ti and Ti-6Al-4V to ascertain their suitability for orthopaedic application. The microstructural studies revealed that Ti-xFe-yTa (x= 8, 9, 10 wt% and y= 0, 2, 5, 8, 9, 10 wt%) alloys substantially consist of α″ and β phases. However, addition of more Fe and Ta β-stabilizers to Ti–8Fe alloy reduced the likelihood to form α″ martensite during quenching, hence decreasing the volume fraction of α″ phase and finally reaching 3% in Ti- 10Fe-10Ta alloy. It is noteworthy noting that all alloys possess higher yield strength (1008- 1560) MPa and hardness (343-468) HV5 than those of CP-Ti and Ti-6Al-4V. However, among them, Ti-10Fe-10Ta alloy with dominant β phase structure exhibits the lowest elastic modulus (92 GPa) and highest plasticity (40%). In Ti-7Fe-xNb (x= 0, 1, 4, 6, 9, 11 wt%), it was observed that only Ti-7Fe-11Nb alloy shows single β phase microstructure, while others are comprised of β and α″ phases. Moreover, Nb addition up to 11 wt% enhances the stability and volume fraction of β phase in the microstructure, hence reducing the propensity of the alloy system to form α″ phase during quenching. Yield strength, hardness and wear rate of the alloys are (985-1847) MPa, (325- 520) HV5 and (3×10-15-1×10-13) m3/m respectively. Among the alloys, Ti-7Fe-11Nb possesses the lowest elastic modulus (84 GPa) and highest deformability (42% strain) due to sence of shear bands indicates excessive deformation as a result of strain localization ADDIN EN.CITE Haghighi2 The mi…
abstract: In this PhD study, using the DV-Xα molecular orbital method three new series of TixFe- yTa, Ti-Fe-xNb and Ti-Nb-xFe alloys are designed for the first time. The alloys are then produced by cold crucible levitation technique. The influence of Ta, Fe and Nb contents on the phase transformation, β phase stability and microstructural evolution of the alloys are investigated. Additionally, the resulting mechanical properties of the alloys are evaluated and compared with those of the widely used biomaterials, i.e. CP-Ti and Ti-6Al-4V to ascertain their suitability for orthopaedic application. The microstructural studies revealed that Ti-xFe-yTa (x= 8, 9, 10 wt% and y= 0, 2, 5, 8, 9, 10 wt%) alloys substantially consist of α″ and β phases. However, addition of more Fe and Ta β-stabilizers to Ti–8Fe alloy reduced the likelihood to form α″ martensite during quenching, hence decreasing the volume fraction of α″ phase and finally reaching 3% in Ti- 10Fe-10Ta alloy. It is noteworthy noting that all alloys possess higher yield strength (1008- 1560) MPa and hardness (343-468) HV5 than those of CP-Ti and Ti-6Al-4V. However, among them, Ti-10Fe-10Ta alloy with dominant β phase structure exhibits the lowest elastic modulus (92 GPa) and highest plasticity (40%). In Ti-7Fe-xNb (x= 0, 1, 4, 6, 9, 11 wt%), it was observed that only Ti-7Fe-11Nb alloy shows single β phase microstructure, while others are comprised of β and α″ phases. Moreover, Nb addition up to 11 wt% enhances the stability and volume fraction of β phase in the microstructure, hence reducing the propensity of the alloy system to form α″ phase during quenching. Yield strength, hardness and wear rate of the alloys are (985-1847) MPa, (325- 520) HV5 and (3×10-15-1×10-13) m3/m respectively. Among the alloys, Ti-7Fe-11Nb possesses the lowest elastic modulus (84 GPa) and highest deformability (42% strain) due to sence of shear bands indicates excessive deformation as a result of strain localization ADDIN EN.CITE Haghighi2 The mi…
author: Ehtemam Haghighi, Shima
keywords: Titanium alloy, Alloy design, Microstructure, Mechanical property, Atomic, Molecular and Optical Physics, Condensed Matter Physics
date published: 2016-01-01T08:00:00Z
date modified: 2026-07-27T19:22:38Z
provider: Edith Cowan University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Edith Cowan University, Research Online, Perth, Western Australia