The influence of hot rolling on oxide development within micro-cracks of aluminum–magnesium alloys
The influence of hot rolling on oxide development within micro-cracks of aluminum–magnesium alloys
复制标题
DOI：
10.1016/j.msea.2014.08.029
复制
发表时间：
2014-11
期刊：
影响因子：
6.4
通讯作者：
O. Gali;M. Shafiei;J. Hunter;A. Riahi
中科院分区：
文献类型：
--
作者：
O. Gali;M. Shafiei;J. Hunter;A. Riahi
研究了热轧道次对铝镁合金横向裂纹的生长、形貌及其表面氧化物的影响。使用热轧摩擦试验机对合金样品进行4次轧制。在第一道次轧制后，在合金表面上观察到裂纹。这些裂纹发生沿着和跨越晶界和传播到亚表面沿着和晶粒内。在裂纹面上观察到具有六方结构的MgO纳米晶颗粒，密封裂纹的狭窄区域。观察到裂纹愈合开始从初始轧制道次通过用MgO密封裂纹。经过4道次轧制后，观察到的所有裂纹均沿次表面区域内的晶界沿着扩展。在轧制的这个阶段，MgO晶粒的六方结构不再明显，但所有的裂纹和损坏区域都填充有多孔MgO层。在热轧的这个阶段，在裂纹内和近表面区域观察到的氧化物的显微结构是相似的。得出的结论是，轧制应力有助于MgO的结构发生在热轧过程中的横向微裂纹内。
The present study investigated the effect of hot rolling passes on the growth and morphology of transverse cracks, and the oxides formed on their surfaces, in an Al–Mg alloy. A hot rolling tribometer was used to carry out 4 rolling passes on the alloy samples. Cracks were observed on the alloy surface after the first rolling pass. These cracks occurred along and across grain boundaries and propagated to the subsurface along and within grains. MgO nanocrystalline grains with a hexagonal structure were observed on crack faces, sealing narrow regions of cracks. Crack healing was observed to begin from the initial rolling pass by the sealing of cracks with MgO. After 4 rolling passes, all cracks observed propagated along grain boundaries within the subsurface regions. The hexagonal structure of the MgO grains was no longer evident at this stage of rolling, but all cracks and damaged areas were filled with porous MgO layers. At this stage of hot rolling the microstructure of the oxides observed within cracks and at the near-surface region was similar. It was concluded that rolling stresses were contributing to the structure of MgO occurring within transverse micro-cracks during hot rolling.