Shock compression and spallation of a eutectic high-entropy alloy(HEA)AlCoCrFeNi_(2.1)with lamellar structure are investigated via plate impact loading with free-surface velocity measurements.The as-cast and postmorte...Shock compression and spallation of a eutectic high-entropy alloy(HEA)AlCoCrFeNi_(2.1)with lamellar structure are investigated via plate impact loading with free-surface velocity measurements.The as-cast and postmortem samples are characterized with transmission electron microscopy,electron back-scatter diffraction and scanning electron microscopy.An accurate Hugoniot equation of state is determined.Af-ter shock compression to∼12 GPa,both the L1_(2)and B_(2)phases retain their ordered structures.Dense dislocations in the{111}slip planes,stacking faults and deformation twins are found in the L1_(2)phase,along with fewer dislocations in the{110}slip bands in the B(2)phase.Shock-induced deformation twin-ning within the L1_(2)phase of this HEA is observed as a new deformation mechanism under various load-ing conditions.For spallation,both ductile and brittle damage modes are observed.The micro voids and cracks prefer to nucleate at the phase boundaries chiefly,then in the B(2)phase.Under similar shock stress,the spall strength of AlCoCrFeNi_(2.1)HEA is about 40%higher than those of other reported dual-phase HEAs due to the high stability of its semi-coherent phase boundaries.展开更多
In December 2024, the world first stand-alone Low Energy high intensity heave ion Accelerator Facility(LEAF) has been commissioned to its design performance and passed the acceptance test conducted by theNational Natu...In December 2024, the world first stand-alone Low Energy high intensity heave ion Accelerator Facility(LEAF) has been commissioned to its design performance and passed the acceptance test conducted by theNational Natural Science Foundation of China. LEAF is designed and built by the Institute of Modern Physics,CAS, which is aiming to provide unprecedent ion beam conditions for the researches of nuclear astrophysics,atomic physics, nuclear materials and so on. To realize this goal, it is essential to develop an ECR (ElectronCyclotron Resonance) ion source beyond the performance of the state-of-the-art machines. This ECR ionsource is called FECR (First 4th generation ECR ion source) designed to be operated with the plasma heatedby 45 GHz microwave frequency that needs high magnetic field confinement. Therefore, with FECR Nb_(3)Snsuperconducting technology was incorporated to ECR ion source for the first time in the world. FECR featuresNb_(3)Sn solenoids and NbTi sextupole coils that enables its high performing operation at 45 + 28 GHz microwaveheating.展开更多
基金sponsored in part by Sichuan Province Key R&D Program(No.2022YFG0033)the National Natural Science Foundation of China(Nos.12102491,52101150,11902274,11627901).
文摘Shock compression and spallation of a eutectic high-entropy alloy(HEA)AlCoCrFeNi_(2.1)with lamellar structure are investigated via plate impact loading with free-surface velocity measurements.The as-cast and postmortem samples are characterized with transmission electron microscopy,electron back-scatter diffraction and scanning electron microscopy.An accurate Hugoniot equation of state is determined.Af-ter shock compression to∼12 GPa,both the L1_(2)and B_(2)phases retain their ordered structures.Dense dislocations in the{111}slip planes,stacking faults and deformation twins are found in the L1_(2)phase,along with fewer dislocations in the{110}slip bands in the B(2)phase.Shock-induced deformation twin-ning within the L1_(2)phase of this HEA is observed as a new deformation mechanism under various load-ing conditions.For spallation,both ductile and brittle damage modes are observed.The micro voids and cracks prefer to nucleate at the phase boundaries chiefly,then in the B(2)phase.Under similar shock stress,the spall strength of AlCoCrFeNi_(2.1)HEA is about 40%higher than those of other reported dual-phase HEAs due to the high stability of its semi-coherent phase boundaries.
基金supported by the National Natural Science Foundation of China(Grant Nos.11427904,12025506)the Scientific Instrument Developing Project of the Chinese Academy of Sciences,Grant No.GJJSTD20210007.
文摘In December 2024, the world first stand-alone Low Energy high intensity heave ion Accelerator Facility(LEAF) has been commissioned to its design performance and passed the acceptance test conducted by theNational Natural Science Foundation of China. LEAF is designed and built by the Institute of Modern Physics,CAS, which is aiming to provide unprecedent ion beam conditions for the researches of nuclear astrophysics,atomic physics, nuclear materials and so on. To realize this goal, it is essential to develop an ECR (ElectronCyclotron Resonance) ion source beyond the performance of the state-of-the-art machines. This ECR ionsource is called FECR (First 4th generation ECR ion source) designed to be operated with the plasma heatedby 45 GHz microwave frequency that needs high magnetic field confinement. Therefore, with FECR Nb_(3)Snsuperconducting technology was incorporated to ECR ion source for the first time in the world. FECR featuresNb_(3)Sn solenoids and NbTi sextupole coils that enables its high performing operation at 45 + 28 GHz microwaveheating.
