(1. 北京科技大學 材料先進制備技術教育部重點實驗室，北京 100083；
2. 北京科技大學 新材料技術研究院，北京 100083)
摘 要: 研究退火溫度對連鑄-軋制成形銅包鋁復合扁排組織、界面結構與結合強度、力學性能以及電學性能的影響。結果表明：銅包覆層在300 ℃開始再結晶，400 ℃時再結晶完成；芯部鋁靠近銅包覆層的劇烈變形區(qū)在200 ℃完成再結晶；而在中心部位，粗晶區(qū)在250 ℃時已開始再結晶，400 ℃時再結晶完成。銅包鋁復合扁排的抗拉強度和伸長率在300 ℃以下退火時變化較小，在300 ℃以上退火時變化顯著。隨著退火溫度的增加，界面結合強度先增大后減少。在250 ℃及以下溫度退火時，界面處無明顯金屬間化合物相生成，因此，在此溫度范圍內，界面結合強度隨著退火溫度的升高而升高；退火溫度在300~400 ℃時，界面處有金屬間化合物相生成，且隨溫度升高，界面厚度由約1 μm增大到約4 μm，界面結合強度由54.0 MPa逐漸降低到25.8 MPa。銅包鋁復合扁排的電阻率主要受基體金屬組織狀態(tài)的影響，隨著退火溫度的升高，銅包鋁扁排的電阻率逐漸降低；在本實驗條件下，當界面處金屬間化合物層的厚度不大于4 μm時，金屬間化合物層對電阻率的影響不明顯。
關鍵字: 連鑄-軋制法；銅包鋁扁排；退火；界面；性能
（1. Key Laboratory for Advanced Materials Processing, Ministry of Education,
University of Science and Technology Beijing, Beijing 100083, China;
2. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The copper cladding aluminum (CCA) flat bar was fabricated by continuous casting-rolling technology, and then, the effects of annealing temperature on the texture, interface structure and bonding strength, mechanical and electrical properties of CCA flat bar were investigated. The results show that the recrystallization of the copper sheath starts at 300 ℃, and completes at 400 ℃. The aluminum along the copper sheath is in the severe deformation zone, and the recrystallization almost completes at 200 ℃. However, the recrystallization of aluminum core in the coarse grain zone starts at 250 ℃, and completes at 400 ℃. The variations of tensile strength and elongation are small when the annealing temperature is below 300 ℃, but becomes large above 300 ℃. The interface bonding strength ascends, and then descends as the annealing temperature rising. When the annealing temperature is not higher than 250 ℃, there is no intermetallic phase generates at the interface, because of which the bonding strength ascends at this temperature range. However, when the annealing temperature is 300-400 ℃, the intermetallic phase forms at the interface, the interface layer thickness increases from about 1 μm to 4 μm, the bonding strength descends from 54.0 MPa to 25.8 MPa. The electrical resistivity is influenced mainly by the microstructures of the component metals. The electrical resistivity of the CCA flat bar descends as the annealing temperature rising. Under the experimental conditions, the interface layer at the interface is less than 4 μm, which has little influence on the electrical resistivity of the CCA flat bar.
Key words: continuous casting-rolling method; copper cladding aluminum flat bar; annealing; interface; property
