摘要
以恒应力方式在Mayes试验机上对自行研制的铸造Mg—Y—Nd合金进行了压缩蠕变实验.结果表明:在温度低于300℃、应力低于100 MPa条件下,Mg-Y-Nd合金具有极其优良的蠕变性能,特别是在200℃时,该合金的稳态蠕变速率较Mg-Zn-Ce合金和普通的AZ80,AM60合金降低约3个数量级;滑移和孪生是Mg—Y—Nd合金蠕变变形的基本方式;大量的β相和蠕变期间沉淀相动态析出产生的沉淀强化和晶界强化是提高该合金蠕变抗力的主要机制,MgO质点薄层(在α-Mg/β相界面间)及其独立聚合区(脱离β相)的生成、动态再结晶的发展和初生β相的断裂是降低该合金蠕变抗力的主要原因.
The compress creep tests of the cast Mg-Y-Nd alloy were carried out at constant stress on Mayes fatigue machine in air. The results show that the creep resistance of the Mg-Y-Nd alloy is much higher when the temperature is lower than 300 degreesC for stress of 100 MPa, especially the steady creep rate at 200 degreesC decreases about three orders of magnitude than those of the Mg-Zn-Ce alloy and common AZ80 and AM60 alloys. Slipping and twinning are the fundamental modes of creep deformation for the alloy, the beta phases and dynamic precipitations during creep are the principal strengthening mechanism of the alloy, whereas the main reason for the decrease of the creep resistance is attributed to occurrence of the MgO particles at the interface between alpha-Mg matrix and beta phase, dynamic recrystallization as well as the fracture of the primary beta phases.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第10期1025-1030,共6页
Acta Metallurgica Sinica
基金
沈阳市科委项目20010167
国家科技部项目2002AA331120资助
