采用等温热压缩测试和TEM分析研究铝锂合金的流变行为与组织演化规律。结果表明:合金的热塑性变形过程受热激活控制,当变形温度低于410℃时,流变曲线具有明显的峰值应力,曲线由加工硬化、动态软化和稳定阶段3个阶段组成;当变形温度高于...采用等温热压缩测试和TEM分析研究铝锂合金的流变行为与组织演化规律。结果表明:合金的热塑性变形过程受热激活控制,当变形温度低于410℃时,流变曲线具有明显的峰值应力,曲线由加工硬化、动态软化和稳定阶段3个阶段组成;当变形温度高于410℃后,峰值应力不明显。随应变量的增加,合金组织演化规律为产生大量无规则缠结位错→"多边化"形成"位错墙"→分割原始晶粒成若干亚晶→亚晶合并长大并同时经受变形→重复上述过程。应变量的增加导致大量空位产生,刃型位错更易攀移、重组和对消,晶内形成亚晶组织。求解得到合金的材料常数如下:结构因子A为2.787×1016;变形激活能Q为217.397 k J/mol;应力指数n为6.11656;应力水平参数α为0.012568 mm2/N。应变速率和温度对合金流变应力的影响可以用包含Arrhenius等式的Z参数表示。展开更多
Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Com...Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Compositions were determined for β phase using thin foil energy dispersive spectroscopy. Precipitation at 400 ℃ involves formation of platelet and block-shaped β phase. The orientation relationship is and between β precipitate phase and α-Mg matrix with habit planes parallel to , and a composition of Mg5(Y0.4Gd0.4Nd0.2) is suggested for the β phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy.展开更多
文摘采用等温热压缩测试和TEM分析研究铝锂合金的流变行为与组织演化规律。结果表明:合金的热塑性变形过程受热激活控制,当变形温度低于410℃时,流变曲线具有明显的峰值应力,曲线由加工硬化、动态软化和稳定阶段3个阶段组成;当变形温度高于410℃后,峰值应力不明显。随应变量的增加,合金组织演化规律为产生大量无规则缠结位错→"多边化"形成"位错墙"→分割原始晶粒成若干亚晶→亚晶合并长大并同时经受变形→重复上述过程。应变量的增加导致大量空位产生,刃型位错更易攀移、重组和对消,晶内形成亚晶组织。求解得到合金的材料常数如下:结构因子A为2.787×1016;变形激活能Q为217.397 k J/mol;应力指数n为6.11656;应力水平参数α为0.012568 mm2/N。应变速率和温度对合金流变应力的影响可以用包含Arrhenius等式的Z参数表示。
基金Project (2011DAE22B01) supported by the Key Technologies Program of China during the 12th Fire-Year Plan Period
文摘Morphology and crystal structure of β precipitate phase in Mg-7Gd-5Y-1Nd-0.5Zr (mass fraction, %) alloy were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy. Compositions were determined for β phase using thin foil energy dispersive spectroscopy. Precipitation at 400 ℃ involves formation of platelet and block-shaped β phase. The orientation relationship is and between β precipitate phase and α-Mg matrix with habit planes parallel to , and a composition of Mg5(Y0.4Gd0.4Nd0.2) is suggested for the β phase in Mg-7Gd-5Y-1Nd-0.5Zr alloy.
