Thermal stability and mechanical properties of nanostructured Ti-24Nb-4Zr-7.9Sn alloy
Thermal stability and mechanical properties of nanostructured Ti-24Nb-4Zr-7.9Sn alloy
复制标题
纳米结构Ti-24Nb-4Zr-7.9Sn合金的热稳定性和力学性能
DOI：
10.1016/j.msea.2007.06.070
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发表时间：
2008-05-15
期刊：
影响因子：
6.4
通讯作者：
Yang, R.
中科院分区：
文献类型：
--
作者：
Li, S. J.;Zhang, Y. W.;Yang, R.
研究了冷轧Ti-24 Nb-4 Zr-7.9Sn合金纳米晶粒的热稳定性及相应的力学性能变化。晶粒生长的活化能被发现明显低于和高于（a + β）/β transsus的类似950 K，与类似的值为47和类似的206 kJ/mol，分别。由于α沉淀物在P晶界处的钉扎效应，在高达773 K的温度下的长时间退火期间，晶粒尺寸可以保持在小于100 nm，并且对于高达923 K的退火温度和高达2 h的时间，晶粒尺寸小于1 μ m。在P转变点以上退火，不到2 h即可得到尺寸为几十微米的粗大晶粒。拉伸和硬度测试表明，在773 K以下，随着退火时间的增加，合金迅速强化，这归因于纳米尺寸α沉淀物的快速形成和P晶粒的缓慢生长速率。通过调整冷轧材料的晶粒尺寸，可以改善植入物应用所需的高强度/低杨氏模量匹配，而不是具有粗晶粒的热轧棒材。(c)2007年由Elsevier B. V.出版。
Thermal stability of the nanostructured grains of cold-rolled Ti-24Nb-4Zr-7.9Sn alloy and corresponding variations in mechanical properties were investigated. The activation energy for grain growth was found distinct below and above the (a + beta)/beta transus of similar to 950 K, with values of similar to 47 and similar to 206 kJ/mol, respectively. Due to the pinning effect of the a precipitates at P grain boundaries, grains sizes can be maintained at less than 100 nm during prolonged annealing at temperatures up to 773 K, and are less than 1 mu m for annealing temperature up to 923 K and time up to 2 h. Annealing above the P transus resulted in coarse grains with sizes of tens of micrometers in less than 2 h. Tensile and hardness tests showed rapid strengthening with the increase of annealing time below 773 K, which was attributed to both the rapid formation of nano-sized a precipitates and the slow growth rate of P grains. By adjusting the grain size of the cold-rolled material the high strength/low Young's modulus match desirable for implant applications can be improved over the hot-rolled bars with coarse grains. (c) 2007 Published by Elsevier B.V.