得益于高效率优势,混合SiC/Si有源钳位(active neutral point clamped,ANPC)三电平电路拓扑在光储发电系统中应用广泛。但传统混合SiC/Si功率模块中,Si器件的使用限制了效率提升,SiC器件引入后又可能导致热分布不均、电压过冲及振荡等...得益于高效率优势,混合SiC/Si有源钳位(active neutral point clamped,ANPC)三电平电路拓扑在光储发电系统中应用广泛。但传统混合SiC/Si功率模块中,Si器件的使用限制了效率提升,SiC器件引入后又可能导致热分布不均、电压过冲及振荡等问题。提出了一种综合设计方法,结合功率器件损耗均衡与功率模块布局寄生电感优化,以提高混合SiC/Si ANPC电路拓扑的功率模块性能。建立了功率模块损耗模型,并进行热性能优化,降低结温与芯片温差;构建了寄生电感模型,通过优化设计减小寄生电感;研制了基于ANPC拓扑的混合SiC/Si功率模块,并开展电热性能测试。实验结果验证了功率模块在损耗、寄生电感及热分布方面的显著优势。展开更多
Non-isothermal aging(NIA)treatments have presented significant advantages in improving the comprehensive performance and aging hardening efficiency of the 7000 series aluminum alloys,but there is no attention paid to ...Non-isothermal aging(NIA)treatments have presented significant advantages in improving the comprehensive performance and aging hardening efficiency of the 7000 series aluminum alloys,but there is no attention paid to their composites.This study takes a linear heating aging process as an example to reveal the precipitation behaviors of a 15 vol.%SiC/7085Al composite as well as its impact on mechanical properties using differential scanning calorimetry,transmission electron microscopy,small-angle neutron scattering,hardness measurements,and tensile testing.The results indicated the formation of GP(Ⅰ,Ⅱ)zones,η’andηprecipitates in sequence,leading to the hardness and strength initially increasing and then decreasing with rising NIA temperatures.The maximums were reached at 183℃,corresponding to the appearance ofη’precipitates in large quantities.Owing to the rapid temperature rise during the NIA process,the precipitates entered the coarsening and redissolution stage before they were entirely formed,resulting in reduced peak strength compared to the T6 treatment.The composite exhibited a more significant reduction in strength than the 7085Al alloy because:(i)the annihilation of vacancies suppressed the formation of GPII zones,thereby weakening their transition toη’precipitates;(ii)quenching dislocations promoted the coarsening of precipitates.An improved NIA process,incorporating both heating and cooling aging treatments,was effectively designed with the assistance of in-situ SANS technology to address this issue,which allows for achieving strength comparable to that after the T6 treatment with only 15%of the aging time consumption.This research fills the gap in investigating the NIA precipitation behaviors of aluminum matrix composites,providing guidance for the formulation of NIA schedules.展开更多
文摘得益于高效率优势,混合SiC/Si有源钳位(active neutral point clamped,ANPC)三电平电路拓扑在光储发电系统中应用广泛。但传统混合SiC/Si功率模块中,Si器件的使用限制了效率提升,SiC器件引入后又可能导致热分布不均、电压过冲及振荡等问题。提出了一种综合设计方法,结合功率器件损耗均衡与功率模块布局寄生电感优化,以提高混合SiC/Si ANPC电路拓扑的功率模块性能。建立了功率模块损耗模型,并进行热性能优化,降低结温与芯片温差;构建了寄生电感模型,通过优化设计减小寄生电感;研制了基于ANPC拓扑的混合SiC/Si功率模块,并开展电热性能测试。实验结果验证了功率模块在损耗、寄生电感及热分布方面的显著优势。
基金support of the Na-tional Key R&D Program of China(No.2021YFA1600700)the Na-tional Natural Science Foundation of China(grant Nos.U22A20114,52322106,52192595,and 52301200)+2 种基金the Project funded by China Postdoctoral Science Foundation(No.2023M733573)CSNS Con-sortium on High-performance Materials of Chinese Academy of Sciences(No.JZHKYPT-2021-01)the Natural Science Foun-dation of Liaoning Province(No.2023-BS-020)。
文摘Non-isothermal aging(NIA)treatments have presented significant advantages in improving the comprehensive performance and aging hardening efficiency of the 7000 series aluminum alloys,but there is no attention paid to their composites.This study takes a linear heating aging process as an example to reveal the precipitation behaviors of a 15 vol.%SiC/7085Al composite as well as its impact on mechanical properties using differential scanning calorimetry,transmission electron microscopy,small-angle neutron scattering,hardness measurements,and tensile testing.The results indicated the formation of GP(Ⅰ,Ⅱ)zones,η’andηprecipitates in sequence,leading to the hardness and strength initially increasing and then decreasing with rising NIA temperatures.The maximums were reached at 183℃,corresponding to the appearance ofη’precipitates in large quantities.Owing to the rapid temperature rise during the NIA process,the precipitates entered the coarsening and redissolution stage before they were entirely formed,resulting in reduced peak strength compared to the T6 treatment.The composite exhibited a more significant reduction in strength than the 7085Al alloy because:(i)the annihilation of vacancies suppressed the formation of GPII zones,thereby weakening their transition toη’precipitates;(ii)quenching dislocations promoted the coarsening of precipitates.An improved NIA process,incorporating both heating and cooling aging treatments,was effectively designed with the assistance of in-situ SANS technology to address this issue,which allows for achieving strength comparable to that after the T6 treatment with only 15%of the aging time consumption.This research fills the gap in investigating the NIA precipitation behaviors of aluminum matrix composites,providing guidance for the formulation of NIA schedules.
