Investigation on microstructure and mechanical properties of Al/Al-Zn-Mg-Cu laminated composite fabricated by accumulative roll bonding (ARB) process
Investigation on microstructure and mechanical properties of Al/Al-Zn-Mg-Cu laminated composite fabricated by accumulative roll bonding (ARB) process
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DOI：
10.1016/j.msea.2018.01.130
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发表时间：
2018-03-07
期刊：
影响因子：
6.4
通讯作者：
Zangeneh, Sh.
中科院分区：
文献类型：
--
作者：
Ebrahimi, S. H. Seyed;Dehghani, K.;Zangeneh, Sh.
本研究首次以Al 1050和超高强度7xxx铝合金板为材料，通过高温累积滚接（ARB）工艺成功制备了Al/Al- zn - mg - cu层压复合材料。在此工艺中，夹层制备后，在每个循环中应用总厚度减少50%。不同ARB循环后的显微组织研究表明，ARB处理导致Al-Zn-Mg-Cu （AZMC）层中二次相分布较细，且其粒度减小较为显著。此外，在前两个循环的塑性变形过程中，观察到ARBed板的所有层保持相对直，没有任何颈缩或断裂。第四次循环后，AZMC层和纯Al （PA）层的宏观组织分别表现为拉长和超细晶粒。此外，计算机模拟显示了ARBed板的应变和应力梯度。力学试验表明，随着ARB循环次数的增加，AZMC层的伸长率、极限抗拉强度（UTS）值和显微硬度值均有显著提高。然而，在ARB过程中，PA层的显微硬度变化很小（< 4%）。断口形貌观察表明，经过ARB作用后，PA层的断口表面主要是颈缩和韧窝，AZMC层的断口表面主要是韧窝和部分剪切区。
In this study, an Al/Al-Zn-Mg-Cu laminated composite was successfully produced for the first time by using Al 1050 and a super high strength 7xxx aluminum alloy sheets through accumulative roll bonding (ARB) process at an elevated temperature. In this process after sandwich preparation, in per cycle applied 50% reduction in total thickness. The microstructural investigations after different ARB cycles showed that ARB process led to a fine distribution of the secondary phases and also a relatively remarkable decrease in their particle size in the Al-Zn-Mg-Cu (AZMC) layer. Furthermore, it was observed that all the layers of the ARBed sheets remained relatively straight without any necking or fracture during the plastic deformation in the first two cycles. Also, the macrostructure showed elongated and ultra-fine grains after the fourth cycle in the AZMC and pure Al (PA) layers, respectively. In addition, computer simulation demonstrated strain and stress gradients in the ARBed sheet. The mechanical examinations displayed a significant improvement of elongation and ultimate tensile strength (UTS) values and also microhardness values of the AZMC layer with increasing the ARB cycles. However, the microhardness variations were so slight ( < 4%) in the PA layer during the ARB process. Fractographic observations revealed that the fractured surfaces of the PA layers consist of necking as well as dimples and that of the AZMC ones include dimples and partly shear regions after ARB process.