TY - JOUR
T1 - Comparison of microstructural evolution in Ti-Mo-Zr-Fe and Ti-15Mo biocompatible alloys
AU - Nag, S.
AU - Banerjee, R.
AU - Stechschulte, J.
AU - Fraser, H. L.
PY - 2005/7
Y1 - 2005/7
N2 - The microstructural evolution and attendant strengthening mechanisms in two biocompatible alloy systems, the binary Ti-15Mo and the quaternary Ti-13Mo-7Zr-3Fe (TMZF), have been compared and contrasted in this paper. In the homogenized condition, while the Ti-15Mo alloy exhibited a single phase microstructure consisting of large β grains, the TMZF alloy exhibited a microstructure consisting primarily of a β matrix with grain boundary α precipitates and a low volume fraction of intra-granular α precipitates. On ageing the homogenized alloys at 600°C for 4 h, both alloys exhibited the precipitation of refined scale secondary α precipitates homogeneously in the β matrix. However, while the hardness of the TMZF alloy marginally increased, that of the Ti-15Mo alloy decreased substantially as a result of the ageing treatment. In order to understand this difference in the mechanical properties after ageing, TEM studies have been carried out on both alloys in the homogenized and homogenized plus aged conditions. The results indicate that the ω precipitates dissolve on ageing in case of the Ti-15Mo alloy, consequently leading to a substantial decrease in the hardness. In contrast, the ω precipitates do not dissolve on ageing in the TMZF alloy and the precipitation of the fine scale secondary α leads to increased hardness.
AB - The microstructural evolution and attendant strengthening mechanisms in two biocompatible alloy systems, the binary Ti-15Mo and the quaternary Ti-13Mo-7Zr-3Fe (TMZF), have been compared and contrasted in this paper. In the homogenized condition, while the Ti-15Mo alloy exhibited a single phase microstructure consisting of large β grains, the TMZF alloy exhibited a microstructure consisting primarily of a β matrix with grain boundary α precipitates and a low volume fraction of intra-granular α precipitates. On ageing the homogenized alloys at 600°C for 4 h, both alloys exhibited the precipitation of refined scale secondary α precipitates homogeneously in the β matrix. However, while the hardness of the TMZF alloy marginally increased, that of the Ti-15Mo alloy decreased substantially as a result of the ageing treatment. In order to understand this difference in the mechanical properties after ageing, TEM studies have been carried out on both alloys in the homogenized and homogenized plus aged conditions. The results indicate that the ω precipitates dissolve on ageing in case of the Ti-15Mo alloy, consequently leading to a substantial decrease in the hardness. In contrast, the ω precipitates do not dissolve on ageing in the TMZF alloy and the precipitation of the fine scale secondary α leads to increased hardness.
UR - http://www.scopus.com/inward/record.url?scp=21344458840&partnerID=8YFLogxK
U2 - 10.1007/s10856-005-2540-6
DO - 10.1007/s10856-005-2540-6
M3 - Article
C2 - 15965601
AN - SCOPUS:21344458840
SN - 0957-4530
VL - 16
SP - 679
EP - 685
JO - Journal of Materials Science: Materials in Medicine
JF - Journal of Materials Science: Materials in Medicine
IS - 7
ER -