冷轧对搅拌摩擦加工Al/Cu复合材料微观组织和力学性能的影响  

Effects of cold rolling on microstructure and mechanical properties of Al/Cu composites processed by friction stir processing

作　　者：马艳恒 张兵[1,2] 张志娟 赵田丽 王快社[1,2] 蔡军 MA Yan-heng;ZHANG Bing;ZHANG Zhi-juan;ZHAO Tian-li;WANG Kuai-she;CAI Jun(College of Metallurgy Engineering,Xi′an University of Architecture and Technology,Xi′an,710055,China;National&Local Engineering Researching Center for Functional Materials Processing,Xi′an,710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]功能材料加工国家地方联合工程研究中心,陕西西安710055

出　　处：《塑性工程学报》2023年第4期118-126,共9页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(5187040179)。

摘　　要：对重叠率为0.5的多道次搅拌摩擦加工(MFSP)制备的Al/Cu复合材料进行了不同变形量的冷轧实验,弥补了MFSP造成的缺陷,对晶粒进行细化和均匀化并进一步提高了其界面结合强度。利用电子背散射衍射技术和剪切实验研究了不同变形量对复合材料界面结构、组织演变和剪切性能的影响。结果表明,在轧制压力作用下,加工区界面由连续变为不连续,过渡区未结合界面逐渐闭合直到结合良好,界面结合机制由单一扩散结合变为扩散结合和机械啮合二者的共同作用。当轧制变形量从30%增加到70%时,加工区和过渡区中Al、Cu各自平均晶粒尺寸的细化效果近乎一致,原始晶粒尺寸差也逐渐消失,由PZ界面原始的20和35μm以及TZ界面原始的25和38μm细化至8~9μm。剪切强度从102.3 MPa增加至374.2 MPa,提高了265.8%,相较原始MFSP试样的剪切强度(75.2 MPa)提高了398%,剪切断口表明断裂方式由韧性断裂转变为脆性断裂,加工硬化和波状界面形貌使界面结合强度有所改善。Cold rolling experiments on Al/Cu composites prepared by multi-pass friction stir processing(MFSP)with overlap rate of 0.5 were carried out to compensate the defects caused by MFSP,and the grains were refined and homogenized and the interface bonding strength was further improved.The effects of different deformation amounts on the interface structure,microstructure evolution and shear properties of composites were studied by electron backscatter diffraction(EBSD)and shear experiments.The results show that,under the action of rolling pressure,the processing zone(PZ)interface changes from continuous to discontinuous,the unbonded interface in transition zone(TZ)gradually closes until the interface is well bonded,and the interface bonding mechanism changes from single diffusion bonding to a joint action of diffusion bonding and mechanical meshing.When the rolling deformation amounts increase from 30%to 70%,the average grain size of Al and Cu in PZ and TZ is almost the same,and the original grain size difference also gradually disappears,from the original 20 and 35μm of PZ interface and the original 25 and 38μm of TZ interface to 8-9μm.The shear strength increases by 265.8%from 102.3 MPa to 374.2 MPa,and the shear strength increases by 398%compared with the original MFSP sample(75.2 MPa).The shear fracture shows that the fracture mode changes from ductile fracture to brittle fracture,and the interface bonding strength is improved by work hardening and wavy interface morphology.

关 键 词：Al/Cu复合材料 多道次搅拌摩擦加工 冷轧 组织演变 剪切性能 

分 类 号：TB331[一般工业技术—材料科学与工程]