Evaluation of mechanical and wear properties of TixNb7Fe alloys designed for biomedical applications. (5th December 2016)

• Record Type: Journal Article
• Authors: Ehtemam-Haghighi, S.; Prashanth, K.G.; Attar, H.; Chaubey, A.K.; Cao, G.H.; Zhang, L.C.
• Is Part Of: Materials & design. Volume 111(2016)
• Page Start: 592
• Page End: 599
• Publication Date: 2016-12-05
• Subjects: Titanium alloy -- Microstructure -- Mechanical property -- Wear; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.09.029
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: A group of TixNb7Fe (x = 0, 1, 4, 6, 9, 11 wt.%) alloys was designed and produced by cold crucible levitation melting process. The microstructural characteristic of the alloys with Nb addition and its effect on their mechanical properties as well as wear resistance were investigated. Microscopic and phase analysis results show that all the alloys, except for the Ti11Nb7Fe, exhibit orthorhombic α" and body-centred cubic β phases, while Ti11Nb7Fe alloy consists of only β phase. It is proposed that increasing the Nb content enhances β phase stability and its proportion in the microstructure of the designed alloys. Depending on the proportion of β and α" phases, TixNb7Fe alloys show varied hardness (3.57–5.92 GPa) and compressive strength (1990–2093 MPa). Additionally, they present wear rates in the range of 3 × 10 − 15 –1 × 10 − 13 m 3 /m which correlates well with the changes in the corresponding microstructures and mechanical properties. Among the studied alloys, Ti11Nb7Fe with β phase microstructure, presents the lowest elastic modulus (86 GPa) and the highest compressive strain (41.5%) along with high compressive strength, hardness and wear resistance. Therefore, it is suggested that this β-type Ti11Nb7Fe alloy is a promising candidate, more suitable than the commercially used CPTi and Ti6Al4V, for orthopedic applications. Graphical abstract: Highlights: Nb addition reduces the α" martensitic phase content in the alloys microstructure. Nb content is inversely proportional to the elastic modulus, hardness and compressive strength of the alloys. The close relationship between the wear resistance, microstructures and mechanical properties of the alloys is discussed. β-type Ti-11Nb-7Fe exhibits better combination of properties than CP-Ti and Ti-6Al-4V for orthopaedic application.