High strength, high electrical conductivity and thermally stable bulk Cu/Ag nanolayered composites prepared by cross accumulative roll bonding-猫眼课题宝

交叉累积滚压法制备高强度、高电导率和热稳定的块体Cu/Ag纳米层状复合材料

DOI：

10.1016/j.matdes.2021.109455

发表时间：

2021-02

期刊：

Materials and Design

影响因子：

8.4

通讯作者：

中科院分区：

材料科学1区

文献类型：

作者：

You Chaoping;Xie Weibin;Miao Shu;Liang Tongxiang;Zeng Longfei;Zhang Xuehui;Wang Hang

采用交叉累积叠轧法（CARB）制备了单层厚度（h）从几百μ m到20 nm的Cu/Ag块体多层复合材料。当层厚度从几百微米减小到20 nm时，具有平坦、平面和尖锐界面的良好定义的连续Cu/Ag多层结构被发现保持稳定。当层厚减小到20 nm时，形成了{110}Cu[111]//{110}Ag[111]的择优界面特征。具体地说，高强度，高导电性和优异的热稳定性，同时在块体Cu/Ag纳米层状复合材料与h = 20 nm。达到938.1 MPa的极限拉伸强度，对应于2.9倍高于基于具有95%轧制压下量的严重变形的Cu和Ag样品的强度的混合物规则估计。此外，获得了高于纯铜的高电导率，同时在高达500 °C的退火温度下保持了高硬度（3.74 GPa）。然而，一旦温度超过500 °C，就会发生机械硬度和纳米层结构的退化。两个主要的机制是负责驱动的热不稳定性在这种碳处理的Cu/Ag纳米层状复合材料，即三重结运动和瑞利不稳定机制的发病。

Bulk Cu/Ag multilayered composites with controlled individual layer thickness (h) varying from several hundred micrometers down to 20 nm were fabricated via cross accumulative roll bonding (CARB). The well-defined, continuous Cu/Ag multilayer structure with flat, planar, and sharp interfaces was found to remain stable when the layer thickness was reduced from several hundred micrometers down to 20 nm. A preferential interface character of {110}Cu[111]//{110}Ag[111] was formed when the layer thickness was reduced to 20 nm. Specifically, high strength, high electrical conductivity and excellent thermal stability were obtained simultaneously in bulk Cu/Ag nanolayered composite with h = 20 nm. Ultimate tensile strength of 938.1 MPa was achieved, corresponding to 2.9 times higher than the rule-of-mixtures estimate based on the strength of the heavily deformed Cu and Ag samples with 95% rolling reduction. Furthermore, a high electrical conductivity higher than that of pure copper was obtained, while high hardness (3.74 GPa) was maintained up to an annealing temperature of 500 °C. Nevertheless, degradation of the mechanical hardness and nanolayered structure occurred once the temperature exceeded 500 °C. Two major mechanisms are responsible for driving the onset of the thermal instability in this CARB-processed Cu/Ag nanolayered composites, namely triple junction motion and Rayleigh instability mechanisms.