Cao Haiyao, Zhan Zaiji, Lv Xiangzhe
State Key Laboratory of Metastable Materials Science & Technology, Yanshan University, Qinhuangdao 066004, China.
Materials (Basel). 2021 Sep 2;14(17):5021. doi: 10.3390/ma14175021.
Gadolinia (GdO) is potentially attractive as a dispersive phase for copper matrix composites due to its excellent thermodynamic stability. In this paper, a series of 1.5 vol% nano-GdO/Cu composites were prepared via an internal oxidation method followed by powder metallurgy in the temperature range of 1123-1223 K with a holding time of 5-60 min. The effects of processing parameters on the microstructure and properties of the composites were analyzed. The results showed that the tensile strength and conductivity of the nano-GdO/Cu composite have a strong link with the microporosity and grain size, while the microstructure of the composite was determined by the sintering temperature and holding time. The optimal sintering temperature and holding time for the composite were 1173 K and 30 min, respectively, under which a maximum ultimate tensile strength of 317 MPa was obtained, and the conductivity was 96.8% IACS. Transmission electron microscopy observations indicated that nano-GdO particles with a mean size of 76 nm formed a semi-coherent interface with the copper matrix. In the nano-GdO/Cu composite, grain-boundary strengthening, Orowan strengthening, thermal mismatch strengthening, and load transfer strengthening mechanisms occurred simultaneously.
由于氧化钆（GdO）具有出色的热力学稳定性，它作为铜基复合材料的弥散相具有潜在吸引力。本文通过内氧化法制备了一系列体积分数为1.5%的纳米GdO/Cu复合材料，随后在1123 - 1223 K的温度范围内进行5 - 60分钟的粉末冶金处理。分析了工艺参数对复合材料微观结构和性能的影响。结果表明，纳米GdO/Cu复合材料的抗拉强度和电导率与微孔率和晶粒尺寸密切相关，而复合材料的微观结构由烧结温度和保温时间决定。该复合材料的最佳烧结温度和保温时间分别为1173 K和30分钟，在此条件下获得的最大极限抗拉强度为317 MPa，电导率为96.8% IACS。透射电子显微镜观察表明，平均尺寸为76 nm的纳米GdO颗粒与铜基体形成了半共格界面。在纳米GdO/Cu复合材料中，晶界强化、奥罗万强化、热失配强化和载荷传递强化机制同时发生。
