Influence of quench rate and microstructure on bendability of AA6016 aluminum alloys
Influence of quench rate and microstructure on bendability of AA6016 aluminum alloys
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DOI：
10.1016/j.msea.2012.08.141
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发表时间：
2013
期刊：
影响因子：
6.4
通讯作者：
P. Castany;F. Diologent;A. Rossoll;J. Despois;C. Bezençon;A. Mortensen
中科院分区：
文献类型：
--
作者：
P. Castany;F. Diologent;A. Rossoll;J. Despois;C. Bezençon;A. Mortensen
研究了固溶处理后淬火速率对AA6016铝合金板材弯曲性能的影响。发现弯曲试验期间的裂纹萌生与淬火速率无关，而快速淬火后裂纹扩展会减少。通过透射电子显微镜对微观结构进行定量分析，重点关注晶界析出物，以将弯曲性能与微观结构相关联。正如文献中先前提出的，裂纹萌生是由于剪切带中大微米级金属间 AlFeSi 颗粒的空洞而引发的。快速淬火促进了球形 Mg2Si 沉淀物沿晶界的形成，从而损害了缓慢冷却后占主导地位的细长 Si 沉淀物。这些硅晶界析出物影响驱动裂纹扩展的微空洞过程，这解释了观察到的裂纹程度对淬火速率的依赖性。另一方面，晶界析出物密度对裂纹萌生或扩展没有影响。
The influence of the quench rate after solution treatment on the bendability of AA6016 aluminum alloy sheets was investigated. Crack initiation during bending tests is found to be independent of quench rate whereas crack propagation is decreased after rapid quenching. A quantitative analysis of microstructures was carried out by transmission electron microscopy, focusing on grain boundary precipitates to correlate bending properties with microstructure. Crack initiation occurs by voiding at large micron-size intermetallic AlFeSi particles in shear bands, as previously proposed in the literature. Rapid quenching promotes the formation along grain boundaries of spherical Mg2Si precipitates to the detriment of elongated Si precipitates that dominate after slow cooling. These Si grain boundary precipitates affect micro-voiding processes that drive crack propagation, which explains the observed dependence of the extent of cracking on quench rate. The grain boundary precipitate density has on the other hand no effect on crack initiation or propagation.