(1. 中南大学材料科学与工程学院，长沙410083；
2. 铜陵有色金属集团股份有限公司金威铜业有限公司，铜陵244000；
3. 中国铝业集团有限公司中铝洛阳铜加工有限公司，洛阳471000；
4. 有研科技集团有限公司有色金属材料制备加工国家重点实验室，北京100088；
5. 有研工程技术研究院有限公司，北京101407)
摘 要: 本文研究了晶界工程处理对超微合金化无氧铜的组织结构与耐热性的影响。通过熔炼铸造制备了超微合金化无氧铜，并对其施以晶界工程处理，测试了晶界工程处理前后超微合金化无氧铜的耐热性，表征了晶界工程处理前后超微合金化无氧铜的组织结构。结果表明：晶界工程处理(每道次的处理工艺为:冷轧20%+(300 ℃, 60 min)退火)可以显著提高超微合金化无氧铜的耐热性，经4道次晶界工程处理的超微合金化无氧铜在(900℃, 60min)退火后晶粒长大不明显，含孪晶的平均晶粒尺寸从23.5 μm增长到29.2 μm，不含孪晶的平均晶粒尺寸从60.4 μm增长到71.9 μm。晶界工程处理也可以有效调控超微合金化无氧铜的组织结构，主要体现为Σ3n重位点阵晶界比例增加和普通晶界网格连通性显著降低。
关键字: 晶界工程；无氧铜；组织结构；耐热性
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Jinvi Copper Co., Ltd., Tongling Nonferrous Metals Group Co., Ltd.,Tongling 244000, China;
3. CHINALCO Luoyang Copper Processing Co., Ltd.,Aluminum Corporation of China Group Co., Ltd., Luoyang 471000, China;
4. State Key Laboratory of Nonferrous Metals and Processes, GRINM Group Co., Ltd., Beijing 100088, China;
5. GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China）
Abstract:In this work, the effect of grain boundary engineering (GBE) treatment on microstructure and thermal stability of an ultra-microalloyed oxygen-free copper was studied. The oxygen-free copper was prepared by melting and casting, and then was subjected to GBE treatment. The thermal stabilitiesof the oxygen-free copper before and after GBE treatment were tested, and their microstructures were also characterized. The results show that the GBE treatment (each pass of it consists of cold rolling with a reduction of 20% followed by annealing at 300 ℃ for 60 min) significantly improves the thermal stability of the oxygen-free copper. After annealing at 900 ℃for 60 min, the grain growth of the oxygen-free copper after 4 passes GBE treatment is a little. The average grain size (including twins) increases from 23.5 μm to 29.2 μm, and the average grain size (excluding twins) increases from 60.4 μm to 71.9 μm. The GBE treatment also hasan influence on the microstructure of the oxygen-free copper, especially increasing the Σ3n coincidence site lattice boundary fraction and decreasing the normal grain boundary network connectivity.
Key words: grain boundary engineering; oxygen-free copper; microstructure; thermal stability
