热轧参数对铸态AZ91镁合金组织与性能的影响

发布时间：2018-05-09 05:00

本文选题：AZ镁合金 + 热轧成形　；参考：《材料热处理学报》2015年12期

【摘要】：通过不同道次压下量和轧制道次的热轧成形实验,研究了不同变形条件对AZ91铸态镁合金组织和析出相演变的影响,以及合金在热轧变形中的开裂行为。实验结果表明:对AZ91镁合金多道次、小压下量轧制是实现其累积大塑性变形的途径之一。在实验轧制条件下,AZ91镁合金塑性变形仍以孪生变形为主,动态再结晶并未明显进行,仅在晶界及析出相附近发生部分不连续动态再结晶。轧制变形过程中,β-Mg_(17)Al_(12)相呈短条棒状或颗粒状分布于晶界附近,且尺寸更为细小。在晶界附近分布的脆性析出相成为微裂纹萌生的源头,随着累积变形量的增加,部分Mg_(17)Al_(12)相被轧碎形成二次裂纹,裂纹进一步沿晶界扩展,造成明显开裂现象。
[Abstract]:The effect of different deformation conditions on the microstructure and precipitation evolution of AZ91 magnesium alloy and the cracking behavior of the alloy during hot rolling deformation were studied by means of hot rolling forming experiments with different pass reduction and rolling pass. The experimental results show that the small reduction rolling is one of the ways to realize the cumulative large plastic deformation of AZ91 magnesium alloy. Under the experimental rolling condition, the plastic deformation of magnesium alloy AZ91 is still mainly twinning deformation, dynamic recrystallization is not obvious, only some discontinuous dynamic recrystallization occurs near grain boundary and precipitate phase. During rolling deformation, the 尾 -MgS17 / AlS-1) phase is distributed in the shape of a short bar or a grain near the grain boundary, and the size of the phase is smaller. The brittle precipitated phase distributed near grain boundary becomes the source of microcrack initiation. With the increase of accumulated deformation, some mg _ S _ (17) Al _ (12) phase is crushed to form a secondary crack, which further extends along the grain boundary, resulting in obvious cracking phenomenon.
【作者单位】：太原理工大学材料科学与工程学院;先进镁基材料山西省重点实验室;山西工程职业技术学院;太原钢铁集团有限公司;
【基金】：国家自然科学基金(51474152) 山西省回国留学人员科研资助项目(2014029)
【分类号】：TG146.22;TG339

【参考文献】