材料期刊网

采用电子背散射衍射（EBSD）技术研究了轧制和退火对黄铜H68样品晶界特征分布（GBCD）的影响。结果表明：再结晶处理后经小变形冷轧（6％）的黄铜H68样品，在650℃×10min退火比在270℃×10min退火和270℃×10min-650℃×10min退火生成更高比例的特殊晶界。进一步分析指出：在应力大小和分布相近的条件下，650oC退火时，晶界迁移的的驱动力大，相比270oC退火更能促使样品中原有及新形成的非共格∑3晶界广泛迁移，在迁移中彼此相遇并发生交互反应，派生出∑9和∑27晶界，使∑3^n（n=1，2，3）特殊晶界的比例增大，当退火10min时，特殊晶界的比例达到峰值；随后如继续保温，在界面能作用下，晶粒合并、长大使特殊晶界比例下降。

A recrystallized brass H68 alloy was cold-rolled with deformation of 6% （thickness reduction） and then annealed at different temperatures. The grain boundary character distributions （GBCD） in the processed samples were studied by means of electron back scatter diffraction （EBSD）. The results show that the fraction of special grain boundaries of brass I-I68 samples annealed at 650℃×10 min is higher than those annealed at 270℃×10 min and 270℃×10min-650℃×10min. Further analysis indicates that under the same stress-strain conditions, annealing at 650 ℃ can provide higher driving force for the migration of varied grain boundaries, the extensive migration of original and newly formed incoherent E3 boundaries can produce a lot of ∑3^n（ n = 1,2,3 ） special boundaries （fsss） , a peak value（74. 1% ）of SBs fraction is achieved when annealing reaches 10 min. Holding longer time at this temperature will decrease the fraction of special boundaries because of grain coarsening by which many special boundaries are swept by random boundaries.