In the as-cast Ti-55 alloy, the intragranular rare earth-rich phase particles are about 1. 0～14 μm in diameter, elliptical, and rich in Nd, Sn, and O. The contents of Nd and Sn on the grain boundaries are higher th...In the as-cast Ti-55 alloy, the intragranular rare earth-rich phase particles are about 1. 0～14 μm in diameter, elliptical, and rich in Nd, Sn, and O. The contents of Nd and Sn on the grain boundaries are higher than those at other sites. The intragranular phases grow preferably at the region on the grain boundaries, which causes the formation of the elliptical morphology of the intragranular phases.展开更多
文摘采用铸造法制备了Mg-8Gd-0.5Zr合金,对合金分别进行固溶处理（T4）及固溶＋时效处理（T6）,在应变速率0.002～0.1 s^-1、变形温度350～500℃、最大变形量50%条件下,对不同热处理后的合金进行热压缩变形实验,分析合金在不同变形条件下的真应力-真应变曲线、激活能及组织变化,研究热处理对热压缩行为的影响。结果表明：合金时效过程中析出β＇-Mg_5Gd相,使热变形过程中峰值应力升高,激活能增加,T6态合金变形激活能（221.605 k J/mol）高于T4态合金（202.986 kJ/mol）;在同样热压缩实验条件下,T6态合金热压缩过程中再结晶开始时间延迟,再结晶晶粒更细小,500℃热压缩后再结晶平均晶粒尺寸为15μm。
文摘In the as-cast Ti-55 alloy, the intragranular rare earth-rich phase particles are about 1. 0～14 μm in diameter, elliptical, and rich in Nd, Sn, and O. The contents of Nd and Sn on the grain boundaries are higher than those at other sites. The intragranular phases grow preferably at the region on the grain boundaries, which causes the formation of the elliptical morphology of the intragranular phases.
