The ultrafine copper wire with a diameter of 18μm is prepared via cold drawing process from the single crystal downcast billet(Φ8 mm),taking a drawing strain to 12.19.In this paper,in-depth investigation of the micr...The ultrafine copper wire with a diameter of 18μm is prepared via cold drawing process from the single crystal downcast billet(Φ8 mm),taking a drawing strain to 12.19.In this paper,in-depth investigation of the microstructure feature,texture evolution,mechanical properties,and electrical conductivity of ultrafine wires ranging fromΦ361μm toΦ18μm is performed.Specially,the microstructure feature and texture type covering the whole longitudinal section of ultrafine wires are elaborately characterized.The results show that the average lamella thickness decreases from 1.63μm to 102 nm during the drawing process.Whereas,inhomogeneous texture evolution across different wire sections was observed.The main texture types of copper wires are comprised of<111>,<001>and<112>orientations.Specifically,the peripheral region is primarily dominated by<111>and<112>,while the central region is dominated by<001>and<111>.As the drawing strain increases,the volume fraction of hard orientation<111>with low Schmid factor increases,where notably higher fraction of<111>is resulted from the consumption of<112>and<001>for the wire ofΦ18μm.For drawn copper wire of 18μm,superior properties are obtained with a tensile strength of 729.8 MPa and an electrical conductivity of 86.9%IACS.Furthermore,it is found that grain strengthening,dislocation strengthening,and texture strengthening are three primary strengthening mechanisms of drawn copper wire,while the dislocation density is the main factor on the reducing of conductivity.展开更多
为提升功率密度,高速化、多极化已成为高性能永磁同步电机的重要发展方向,但也使永磁同步电机的高频化特性愈加明显,高频交流铜耗问题也愈加突出。由成型利兹线制成的定子绕组嵌线可有效抑制集肤效应、临近效应和环流效应带来的交流损耗...为提升功率密度,高速化、多极化已成为高性能永磁同步电机的重要发展方向,但也使永磁同步电机的高频化特性愈加明显,高频交流铜耗问题也愈加突出。由成型利兹线制成的定子绕组嵌线可有效抑制集肤效应、临近效应和环流效应带来的交流损耗,在高性能永磁电机领域具有良好的应用前景。有限元法可实现成型利兹线绕组高频铜耗的准确计算,但利兹线建模复杂,计算成本高。该文提出一种将Torukhani模型与等效磁网络法相结合的定子槽内成型利兹线绕组高频铜耗解析计算方法,其在传统Torukhani模型的基础上,基于等效磁网络法计算磁饱和修正系数,对定子槽内漏磁场进行修正,弥补了传统Torukhani模型无法考虑铁心磁饱和影响的不足。与有限元方法对比表明,该方法可实现0~30 k Hz范围内成型利兹线绕组高频铜耗的高效计算,计算精度可满足工程需求,并通过定子槽内成型利兹线绕组的交流电阻系数测量试验,验证方法合理性与正确性。该方法可为永磁同步电机损耗与温度场的精确分析提供参考与借鉴。展开更多
基金Project supported by“Unveiled the List of Commanders”Key Core Common Technology Projects of Ji’an,ChinaProject(LJKMZ20220591)supported by the Basic Scientific Research Project of the Education Department of Liaoning Province,ChinaProject(CSTB2023NSCQ-LZX0116)supported by the Natural Science Foundation Joint Fund for Innovation and Development Projects of Chongqing,China。
文摘The ultrafine copper wire with a diameter of 18μm is prepared via cold drawing process from the single crystal downcast billet(Φ8 mm),taking a drawing strain to 12.19.In this paper,in-depth investigation of the microstructure feature,texture evolution,mechanical properties,and electrical conductivity of ultrafine wires ranging fromΦ361μm toΦ18μm is performed.Specially,the microstructure feature and texture type covering the whole longitudinal section of ultrafine wires are elaborately characterized.The results show that the average lamella thickness decreases from 1.63μm to 102 nm during the drawing process.Whereas,inhomogeneous texture evolution across different wire sections was observed.The main texture types of copper wires are comprised of<111>,<001>and<112>orientations.Specifically,the peripheral region is primarily dominated by<111>and<112>,while the central region is dominated by<001>and<111>.As the drawing strain increases,the volume fraction of hard orientation<111>with low Schmid factor increases,where notably higher fraction of<111>is resulted from the consumption of<112>and<001>for the wire ofΦ18μm.For drawn copper wire of 18μm,superior properties are obtained with a tensile strength of 729.8 MPa and an electrical conductivity of 86.9%IACS.Furthermore,it is found that grain strengthening,dislocation strengthening,and texture strengthening are three primary strengthening mechanisms of drawn copper wire,while the dislocation density is the main factor on the reducing of conductivity.
文摘为提升功率密度,高速化、多极化已成为高性能永磁同步电机的重要发展方向,但也使永磁同步电机的高频化特性愈加明显,高频交流铜耗问题也愈加突出。由成型利兹线制成的定子绕组嵌线可有效抑制集肤效应、临近效应和环流效应带来的交流损耗,在高性能永磁电机领域具有良好的应用前景。有限元法可实现成型利兹线绕组高频铜耗的准确计算,但利兹线建模复杂,计算成本高。该文提出一种将Torukhani模型与等效磁网络法相结合的定子槽内成型利兹线绕组高频铜耗解析计算方法,其在传统Torukhani模型的基础上,基于等效磁网络法计算磁饱和修正系数,对定子槽内漏磁场进行修正,弥补了传统Torukhani模型无法考虑铁心磁饱和影响的不足。与有限元方法对比表明,该方法可实现0~30 k Hz范围内成型利兹线绕组高频铜耗的高效计算,计算精度可满足工程需求,并通过定子槽内成型利兹线绕组的交流电阻系数测量试验,验证方法合理性与正确性。该方法可为永磁同步电机损耗与温度场的精确分析提供参考与借鉴。
