(1. 北京科技大學 現(xiàn)代交通金屬材料與加工技術北京實驗室，北京 100083；
2. 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；
3. 北京科技大學 北京材料基因工程高精尖創(chuàng)新中心，北京 100083)
摘 要: 采用HCCM立式連鑄技術制備鋁白銅棒坯，并進行不同壓下量的軋制變形，研究連鑄速度和軋制變形對棒材組織性能的影響。通過拉伸實驗分析不同狀態(tài)下棒材的力學性能變化，利用光學顯微鏡(OM)、電子背散射衍射系統(tǒng)(EBSD)、掃描電子顯微鏡(SEM)、能量色散譜(EDS)觀察棒材的微觀組織形貌。結果表明：當金屬液溫度為(1300±5) ℃、熱型加熱溫度為(1250±5) ℃、冷卻水流量為400 L/h、連鑄拉坯速度為0.5~2.0 mm/s時，可制備出具有連續(xù)柱狀晶組織和優(yōu)良力學性能的鋁白銅棒坯。隨著連鑄速度由0.5 mm/s增大至2.0 mm/s時，粗大柱狀晶組織逐漸轉變?yōu)榕c連鑄方向呈一定角度的柱狀晶組織和等軸晶組織，抗拉強度呈增大趨勢，為311~418 MPa，斷后伸長率由69.2%降低至64.9%；存在于晶界處及枝晶間的富鋁β相數(shù)量增多、分布變得均勻。隨著冷軋變形量由0增大至80%，抗拉強度呈線性增長；繼續(xù)增大變形量，抗拉強度增速放緩。隨著冷軋變形量由0增大至40%，斷后伸長率呈線性降低；當冷軋變形量為40%~94%時，斷后伸長率穩(wěn)定在5%左右，展現(xiàn)出柱狀晶組織較好的可持續(xù)加工性能，但連鑄速度及軋制變形對柱狀晶的影響機理有待進一步驗證。
關鍵字: 鋁白銅；HCCM立式連鑄；冷軋；組織；力學性能
（1. Beijing Laboratory of Metallic Materials and Processing for Modern Transportation, University of Science and Technology Beijing, Beijing 100083, China;
2. Key Laboratory for Advanced Materials Processing, Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China;
3. Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The HCCM vertical continuous casting technology was used to prepare aluminum white copper bar billets, and rolling with different reduction was carried out, so as to study the effect of continuous casting speed and rolling deformation on the microstructure and properties. The mechanical properties of the bar under different conditions were analyzed by tensile test. The microstructure and orientation of the bar were observed by OM, EBSD, SEM and EDS. The results show that , when the temperature of the molten metal is (1300±5) ℃, the heating temperature is (1250±5) ℃, the cooling water flow rate is 400 L/h, and the continuous casting billet speed is 0.5-2.0 mm/s, aluminum white copper bar billets with columnar crystal structure along the continuous casting direction and excellent mechanical properties can be prepared. With the continuous casting speed increasing from 0.5 mm/s to 2.0 mm/s, the coarse columnar crystal structure gradually changes into the columnar crystal structure with an angle to the continuous casting direction and equiaxed crystal structure, and the tensile strength tends to increase in the range of 311-318 MPa, and the elongation decreases from 69.2% to 64.9%. In addition, the aluminum-rich β phases increase and the distribution becomes more uniform. With the cold rolling deformation increasing from 0 to 80%, the tensile strength increases linearly. With the further increase of deformation, the growth rate of tensile strength slows down. With the cold rolling deformation increasing from 0 to 40%, the elongation decreases linearly. When the cold rolling deformation is in the range of 40%-94%, the elongation is stable at about 5%, showing good sustainable processing performance of columnar crystal structure. However, the influence mechanism of continuous casting speed and rolling deformation on columnar crystal needs to be further verified.
Key words: aluminium white copper; HCCM vertical continuous casting; cold rolling; microstructure; mechanical properties
