(北京科技大学 材料科学与工程学院，北京 100083)
摘 要: 采用冷静液挤压的方法将银管套装铝棒坯料挤压成银包铝线材，再通过多道次拉拔制备外径小于d 100 μm的银包铝丝材。结果表明：银管和铝棒的硬度比和模角大小对静液挤压银包铝复合线材的稳定制备具有显著的影响，当管和铝芯棒的硬度比为50׃20、模角为45˚时，可以成功制备质量良好的银包铝复合线坯。合理的拉拔和退火工艺为：分别在丝径拉拔至d 1.7、0.28和0.09 mm时各退火一次，d 1.7 mm线材退火温度为200 ℃，保温时间5 min；其余情况下，退火温度为150 ℃，保温时间5 min。制备的名义外径为d 70 μm丝材的丝径和包覆层厚度测试结果表明：丝径为(70±2) μm，包覆层厚度为9~12 μm。外径为90、70和40 μm的丝材在150 ℃、5 min退火后的拉伸强度分别为151、177和183 MPa，伸长率分别为9.69%、4.41%和2.34%。
关键字: 银包铝丝材；静液挤压；多道次拉拔；力学性能
（School of Materials Science and Engineering,University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Silver clad aluminum wires (diameter less than 100 μm) were fabricated through cold hydrostatic extrusion followed by drawing process. The results show that the ratio of hardness of silver tube to aluminum rod and modular angle are the critical factors that contribute to the success of the hydrostatic extrusion process. When the ratio of hardness of silver clad to aluminum rod is 50׃20 and modular angle is 45˚, good silver clad aluminum wires can be fabricated successfully. The appropriate drawing and annealing process is that wire should be annealed while its diameter is 1.7, 0.28 and 0.09 mm respectively and the temperature and the hold time of the first annealing are 200 ℃ and 5 min respectively, and for the rest, are 150 ℃ and 5 min respectively. The measurement results show that the diameter and silver clad thickness of the wire (70 μm in nominal diameter) are (70±2) μm and (9−12) μm, respectively. For the wires of 90, 70 and 40 μm in diameter annealed at 150 ℃ for 5 min, the tensile strengths are 151, 177 and 183 MPa respectively, and the elongations are 9.69%, 4.41% and 2.34%, respectively.
Key words: silver clad aluminum wire; hydrostatic extrusion; drawing with multi-passes; mechanical property
