矩形断面铜包铝连铸坯轧制成形导电扁排的工艺及性能
Rolling process and properties of copper cladding aluminum flat bars using continuous casting bars with the rectangle section
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摘要: 采用水平连铸直接复合成形工艺制备了断面尺寸为50 mm×30 mm×3 mm×R4 mm的铜包铝复合棒材,通过多道次平辊轧制和精整拉拔,制备了断面尺寸为60 mm×8 mm的铜包铝复合扁排,研究了合理的轧制工艺、扁排的力学和导电性能.结果表明:扁排的最终轧后宽度与侧边部开裂具有相关性,可通过轧制过程的压下量分配和轧制温度控制扁排宽度,从而防止边部开裂.合理的轧制温度为室温至200℃.在室温平辊轧制时,较为合理的轧制制度为5道次平辊轧制,第1道次压下率为20%左右,最大道次压下率为30%左右.轧后经1道次精整拉拔,可获得外形尺寸精确、表面质量良好的铜包铝复合扁排.经退火处理后,铜包铝复合扁排电阻率为2.084×10-8Ω·m,抗拉强度为122.7 MPa,延伸率为22.0%,界面剪切强度为25.9 MPa.Abstract: Copper cladding aluminum (CCA) rods with the section dimensions of 50 mm × 30 mm × 3 mm × R4 mm were fabricated by horizontal core-filling continuous casting (HCFC) technology, and then CCA flat bars with the section dimensions of 60 mm × 8 mm were formed from the CCA rods by multi-pass rolling and finishing drawing process. The reasonable rolling process, mechanical properties and electrical properties of the flat bars were investigated subsequently. The results confirm the correlation between the width of the flat bars after rolling and the side-edge cracking behavior. The width of the flat bars can be controlled by allocating the pass reduction and setting the temperature of the rolling process, thereby suppressing the side-edge cracking in the flat bars. The reasonable rolling temperature range is from room temperature to 200℃. When rolling at room temperature, the much reasonable rolling schedule is 5 passes flat rolling, the 1st pass reduction of about 20% and the highest pass reduction of about 30%. Through 1 pass finishing drawing after the rolling process, the flat bars can be obtained with precise section size and excellent surface quality. After annealing treatment, the electrical resistivity of the flat bar is 2.084 × 10-8 Ω·m, the tensile strength is 122.7 MPa, the elongation is 22.0% and the shear bonding strength of the interface is 25.9 MPa.