摘要
采用室温水作为淬火介质进行Jom iny末端淬火实验,采集了合金淬火过程试样的温度-时间变化曲线,测定了末端淬火试样距淬火端不同距离合金的淬火态电导率和硬度,结合透射电镜组织观察,研究了冷却速率对合金过饱和固溶体脱溶析出的影响,通过观察淬火析出相非均质形核,考察了7050合金过饱和固溶体淬火脱溶析出相的析出规律。结果表明,淬火冷却速率对7050合金的过饱和固溶体的脱溶析出行为有着显著影响。末端淬火实验过程中,合金过饱和固溶体大角晶界、小角晶界、晶内弥散相周围分别在距淬火端5,10和15 mm出现淬火析出相。随着距淬火端距离的增加,淬火态合金导电率呈上升趋势,合金淬火析出相尺寸变大,体积分数增加。合金淬火平衡η相的非均质形核核心的优先次序为:晶界、亚晶界、A l3Zr等纳米级弥散相粒子。
The Jominy end quench test was used to evaluate the hardenability of 7050 alloys.Room-temperature water was adopted as quenching media.Heating and cooling rate of the 7050 bar was monitored.The as-quenched hardness and electrical conductivity as well as the microstructure of alloys at different distances from the quenched end were collected.The results indicated that the precipitation of the quenched-induced precipitates was influenced by the cooling rate greatly.The quench-induced precipitates appeared at grain boundary,subgrain boundary and Al3Zr dispersoids in-grains at 5,10 and 15 mm from the quenched end,respectively.The electrical conductivity was increased with the increasing of distances from the qnenched end of the bar.The volume and size of equilibrium η phase induced by the decrease of cooling rate increased along the distance from the quenched end,which led to the quench sensitive of the alloy.The priority of the heterogeneous nucleation of the quench-induced precipitation in the 7000 series alloy could be summarized as： grain boundaries,sub-boundaries,second-phase particles like Al3Zr dispersoid.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2011年第3期322-329,共8页
Chinese Journal of Rare Metals
基金
国家自然科学基金(50904010)
国际科技合作项目(2010DFB50340)资助
关键词
末端淬火
电导率
冷却速率
非均质形核
jominy end quench
electrical conductivity
cooling rate
heterogeneous nucleation
