未找到相关数据
Structure evolution and thermal stability of SMAT-derived nanograined layer on Ti-25Nb-3Mo-3Zr-2Sn alloy at elevated temperatures
被引：0
|作者：
机构：
[1] Huang, Run
[2] Han, Yong
来源：
Han, Y. (yonghan@mail.xjtu.edu.cn)
|
1600年
/
Elsevier Ltd卷
/
554期
关键词：
A nanocrystalline layer;
which consists of pure β phase with average grain size of about 30 nm on Ti-25Nb-3Mo-3Zr-2Sn alloy;
was fabricated by surface mechanical attrition treatment (SMAT). The microstructure evolution;
phase transitions and thermal stability of the nanocrystalline layer during isochronal annealing at temperatures of 300-600 °C were investigated by XRD and TEM. During annealing;
the nanocrystalline layer underwent recovery;
recrystallization and significant grain growth. Recovery occurs at temperatures from 300 to 400 °C resulting in strain relaxation;
dislocation annihilation and a very limited growth of β grains dominated by re-ordering of grain boundaries (GBs). α Precipitates start to precipitate along the β GBs at 350 °C;
which exhibit equiaxed morphology with size less than 10 nm. Recrystallization proceeds at a higher temperature up to 450 °C leading to a reduction of β grain size. Due to the pinning effect of the α precipitates;
β grains sizes can be maintained less than 100 nm until the annealing temperature increased to 550 °C;
e.g;
0.41 Tm (melting temperature in K);
above which significant grain growth occurs to overstep nanocystalline scale;
and the growth activation energy of β grains is calculated as 40.8 kJ/mol. The abnormal low value is caused by the nonequilibrium GBs of β grains in the as-SMATed surface layer;
which increase atomic mobility even in the presence of pinning effect of the α precipitates on the β GBs. © 2012 Elsevier B.V. All rights reserved;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
Journal article (JA)
引用
收藏
相关论文