冷轧变形Pb-Ca基合金在退火过程中的晶界特征分布

Grain boundary character distribution(GBCD) of cold-rolled Pb-Ca-based alloy during annealing

采用电子背散射衍射(EBSD)技术研究了冷轧变形Pb-0.1%Ca-1.5%Sn-0.026%A l合金在退火过程中的晶界特征分布(GBCD)。结果表明:经10%冷轧变形后在220℃退火72小时,合金内形成了比例超过60%的平直的∑3共格孪晶界,这类晶界不处在由一般大角度晶界构成的晶界网络上,不能使合金的GBCD得到优化;相反,经30%冷轧变形后在270℃退火7分钟,除了生成比例超过65%的∑3晶界外,还出现了较多的∑9和∑27等低∑重位点阵晶界(CSL),并且这些晶界和相当多的弯曲的∑3晶界均处在由一般大角度晶界构成的晶界网络上,可以使合金的GBCD得到优化。

The grain boundary character distribution （GBCD） of a cold-rolled Pb-0. 1% Ca-1. 5% Sn-0. 026% Al alloy during annealing was investigated by means of electron back scatter diffraction. The results indicate straight∑ 3 coherent twin boundaries of over 60% （all values are given as a length fraction of the total boundary length） are introduced in the alloy when annealed at 220℃ for 72 hours after cold rolling to 10% reduction in thickness. Such boundaries are not distributed in a network of general high angle boundaries （HABs） and the GBCD is not optimized. However, for annealing at 270℃ for 7 minutes of samples cold rolled to 30% , apart from ∑3 boundaries of over 65% , a fair amount of ∑9 and ∑27 coincidence site lattice boundaries were also developed. These ∑9 and ∑27 boundaries along with the large number of curved ∑3 boundaries are located in a network of HABs and the GBCD is optimized.