Impact deformation behaviors of CT20 alloy with lamellar microstructure(LM),equiaxed microstructure(EM)and bimodal microstructure(BM)at room temperature were systematically investigated in this study.The experimental ...Impact deformation behaviors of CT20 alloy with lamellar microstructure(LM),equiaxed microstructure(EM)and bimodal microstructure(BM)at room temperature were systematically investigated in this study.The experimental results indicated the excellent mechanical properties of CT20 alloy with BM un-der dynamic load.The impact toughness of BM specimen(∼118 J/cm^(2))is∼17.5%higher than that of LM specimen and∼33.8%higher than that of EM specimen.The impact energy of EM specimen is the lowest due to the relatively simple equiaxed microstructure.LM specimen can absorb the highest crack initia-tion energy due to the best twinning ability.The highest impact toughness of BM specimen is induced by multi-factor coupling during impact deformation.Finer initial equivalent grain size,smaller lamellar thickness,lamellar induces twinning,finer twins,crack propagation path,and interaction between twins andβlamellar are all factors affecting impact toughness.展开更多
CT20弹簧操动机构因其一系列优点,被广泛使用在126 k V电压等级的断路器上。随着开断能量的增大,CT20机构原有设计参数可能无法满足更高容量断路器的需求,如果没有采取对应的措施,那么机构合闸过程中合闸保持掣子的振动可能会造成合闸...CT20弹簧操动机构因其一系列优点,被广泛使用在126 k V电压等级的断路器上。随着开断能量的增大,CT20机构原有设计参数可能无法满足更高容量断路器的需求,如果没有采取对应的措施,那么机构合闸过程中合闸保持掣子的振动可能会造成合闸动作失败。针对这一问题,笔者基于合闸保持过程中合闸保持掣子的振动作为研究点,开展机构合闸过程的动力学仿真分析,然后利用试验手段,以高速摄影机为主要设备,拍摄并记录合闸过程中的合闸保持掣子振动,最后结合仿真与试验的研究结果,分析合闸保持掣子振动对合闸性能的影响,同时提出减小合闸保持掣子振动的方法。从文中研究可以得到:一般而言,CT20弹簧操动机构的合闸保持大小掣子的振动时间持续10 ms左右,该时间段为合闸保持成功与否的关键;合闸保持大掣子振幅系数为7.6%,合闸保持小掣子的振幅系数为28.6%;振幅太大或者振动时间太久,均可能会造成合闸保持的失败。展开更多
基金financially supported by the National Key Re-search and Development Program of China(No.2022YFB3705605)the Science and Technology Major Project of Shaanxi Province of China(No.2020zdzx04-01-02)+1 种基金the National Natural Science Foun-dation of China(No.52101122)the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(No.6142902220202).
文摘Impact deformation behaviors of CT20 alloy with lamellar microstructure(LM),equiaxed microstructure(EM)and bimodal microstructure(BM)at room temperature were systematically investigated in this study.The experimental results indicated the excellent mechanical properties of CT20 alloy with BM un-der dynamic load.The impact toughness of BM specimen(∼118 J/cm^(2))is∼17.5%higher than that of LM specimen and∼33.8%higher than that of EM specimen.The impact energy of EM specimen is the lowest due to the relatively simple equiaxed microstructure.LM specimen can absorb the highest crack initia-tion energy due to the best twinning ability.The highest impact toughness of BM specimen is induced by multi-factor coupling during impact deformation.Finer initial equivalent grain size,smaller lamellar thickness,lamellar induces twinning,finer twins,crack propagation path,and interaction between twins andβlamellar are all factors affecting impact toughness.
文摘CT20弹簧操动机构因其一系列优点,被广泛使用在126 k V电压等级的断路器上。随着开断能量的增大,CT20机构原有设计参数可能无法满足更高容量断路器的需求,如果没有采取对应的措施,那么机构合闸过程中合闸保持掣子的振动可能会造成合闸动作失败。针对这一问题,笔者基于合闸保持过程中合闸保持掣子的振动作为研究点,开展机构合闸过程的动力学仿真分析,然后利用试验手段,以高速摄影机为主要设备,拍摄并记录合闸过程中的合闸保持掣子振动,最后结合仿真与试验的研究结果,分析合闸保持掣子振动对合闸性能的影响,同时提出减小合闸保持掣子振动的方法。从文中研究可以得到:一般而言,CT20弹簧操动机构的合闸保持大小掣子的振动时间持续10 ms左右,该时间段为合闸保持成功与否的关键;合闸保持大掣子振幅系数为7.6%,合闸保持小掣子的振幅系数为28.6%;振幅太大或者振动时间太久,均可能会造成合闸保持的失败。
基金Project (51175429) supported by the National Natural Science Foundation of ChinaProject (NCET-08-0462) supported by the Program for New Century Excellent Talents in University+2 种基金Project (51222509) supported by the National Natural Science Fund for Excellent Young Scholar of ChinaProject (B08040) supported by the 111 ProjectProject (JC201136) supported by NPU Foundation for Fundamental Research, China
