【摘要】 为了解高温退火前后V-4%Cr-4%Ti(记为V-4Cr-4Ti,下同)合金微观组织结构的变化,将合金在1000～1400℃,1×10-2Pa条件下退火不同时间(1h或3h)后,利用透射电子显微镜(TEM)分析了退火前后合金中位错、层错及孪晶的形态。分析结果表明,铸态合金中含有少量的层错和孪晶,但位错密度较高。高温退火后合金中的位错密度降低,层错、扩展位错的密度增加。孪晶密度随退火温度和退火时间的增加而增加。1200℃退火合金中的层错呈现规则的平行排列,层错使得基体衍射点发生分裂;孪晶的孪生面为钒的{211}晶面。在1300℃/3h退火合金中观察到了由大量微孪晶和位错组成的类"马氏体"结构。更多还原

【Abstract】 The alloy samples of V-4%Cr-4%Ti(V-4Cr-4Ti)alloy were annealed at 1000~1400 ℃,1×10-2 Pa at different times(1 h or 3 h).The behaviour of dislocation,stacking fault and twin of alloy before/after anneal was analysed using transmission electron microscopy(TEM).The results showed that the dislocation density was very high in as-melt alloy with a small amount of stacking fault and twin.After annealing,the density of dislocation decreased but stacking fault and extended dislocation increased.The number of twin increased with the increase of anneals temperature and time.In the alloy annealed at 1200 ℃,the stacking fault paralleled to each other and resulted in the diffraction point of vanadium split,and the twin plane was the {211} plane of vanadium.The microstructure of alloy annealed at 1300 ℃/3 h was consisted of high-density twin and dislocation,which was named as "martensite-like" structure.In order to understand the evolvement of microstructure before and after high-temperature annealing.更多还原