固溶和预时效Pb合金冷轧退火后的晶界特征分布

GRAIN BOUNDARY CHARACTER DISTRIBUTIONS OF COLD ROLLED AND ANNEALED Pb ALLOY AFTER SOLID SOLUTION AND PRE-AGEING TREATMENTS

采用电子背散射衍射(EBSD)技术研究了不同固溶及预时效状态下Pb-0．05Ca-1．5Sn-0．026Al(质量分数,％)合金冷轧退火后的晶界特征分布(GBCD)．结果表明,290℃固溶处理后冷轧退火的合金样品中出现了较多的特殊晶界,∑3和(∑9+∑27)晶界的比例分别达到49．6％和7．2％,并且特殊晶界能较好地阻断一般大角度晶界网络的连通性;固溶后先进行100及200℃预时效处理,然后再进行冷轧退火的合金样品中形成了较少的特殊晶界,∑3和(∑9+∑27)晶界的比例分别低于35．9％和2．5％,特殊晶界几乎不能阻断一般大角度晶界网络的连通性．

The grain boundary character distributions （GBCD） of cold rolled and annealed Pb-0.05Ca-1.5Sn-0.026Al （mass fraction, %） alloy after solid solution and pre-ageing treatments were investigated by means of electron back scatter diffraction （EBSD） techniques. The results indicate that special boundaries were largely populated in the specimen which was cold rolled and annealed after solid solution treatment at 290 ℃. The fractions of ∑3 and （∑9-＋-∑27） grain boundaries reached 49.6% and 7.2%, respectively. The connectivity of general high angle boundaries （HABs） network was interrupted substantially by the above special boundaries. However, low fraction of special boundaries were developed in the specimen which was cold rolled and annealed after solid solution plus preageing at 100 and 200 ℃, the fractions of ∑3 and （∑9＋∑27） boundaries are less than 35.9% and 2.5%, respectively, and the connectivity of general high angle boundaries （HABs） network was not interrupted significantly.