摘要
采用光学显微镜、透射电镜观察、硬度及单向拉伸测试,研究了双级均匀化制度对7055合金微结构与性能的影响。结果表明:与单级均匀化相比,双级均匀化处理的初级低温保温过程有利于原始晶界附近低Zr区域的Al3Zr弥散析出;双级均匀化处理后无沉淀析出带(PFZ)变窄,晶界附近Al3Zr粒子密度增加;弥散分布的Al3Zr粒子通过钉扎晶界与拖曳位错,有效地抑制了再结晶,以至于经热轧固溶后再结晶百分数降低40%左右;保留下来的大量位错和未再结晶组织,提高了合金T6态力学性能。
The effect of homogenization on the microstructure and properties of a 7055 alloy was investigated by optical microscopy,transmission electron microscopy,Vickers hardness test and uniaxial tensile test.It is found that the initial low-temperature preheating for the two-stage homogenization,comparing with the single-stage homogenization,can achieve a higher density of Al3Zr particles,and a narrower precipitating free zone（PFZ）.It is suggested from microstructural analysis that the dispersion distribution of fine Al3Zr particles decreased the recrystallized fraction by 40% due to the efficient dragging effect of Al3Zr particles on the grain boundaries and dislocations.Meanwhile,the unrecrystallized microstructure containing profuse dislocations enhanced the mechanical properties of the studied alloy at the T6 state.
出处
《武汉理工大学学报》
CAS
CSCD
北大核心
2011年第7期10-13,共4页
Journal of Wuhan University of Technology
基金
湖南省自然科学基金(09JJ6082)
湖南省教育厅一般项目(08C258)
