In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and5...In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and56Fe ions at the terminal of a cyclotron to three successively increasing damage levels of 0.05,0.1 and 0.2 displacements per atom(dpa)at about-50°C.The energy of the incident ions was dispersed to 11 successively decreasing grades using an energy degrader,thereby generating an atomic displacement damage plateau in the specimens from the surface to a depth of 25μm,which is sufficiently broad for the Vickers hardness test.Eight different loads(i.e.98 mN,196 m N,490 m N,980 m N,1.96 N,4.9 N,9.8 N and 19.6 N)were applied to the specimens to obtain the depth profiles of the Vickers hardness by using a microhardness tester.Hardening was observable at the lowest damage level,and increased with increasing irradiation dose.A power-law correlation of the Vickers hardness with the damage level(HV0=1.49+0.76 dpa0.31)is proposed.Testing with a nano-indentation technique was also performed,and a linear relationship between the Vickers micro-hardness and the nanohardness(HV0=0.83 H0)was observed.A comparison with other RAFM steels(CLAM,JLF-1,F82 H,EUROFER97 etc.)under neutron or charged particle irradiation conditions shows that most of the RAFM steels exhibit similar power-law exponents in the dose dependence of irradiation hardening.The difference in the irradiation hardening may be attributed to differences in microstructure prior to irradiation.展开更多
Metallic nanoparticle （NP） shapes have a significant influence on the property of composite embedded with metallic NPs. Swift heavy ion irradiation is an effective way to modify shapes of metallic NPs embedded in an...Metallic nanoparticle （NP） shapes have a significant influence on the property of composite embedded with metallic NPs. Swift heavy ion irradiation is an effective way to modify shapes of metallic NPs embedded in an amorphous matrix. We investigate the shape deformation of Ag NPs with irradiation fluence, and 357 MeV Ni ions are used to irradiate the silica containing Ag NPs, which are prepared by ion implantation and vacuum annealing. The UV-vis results show that the surface plasmon resonance （SPR） peak from Ag NPs shifts from 400 to 377nm. The SPR peak has a significant shift at fluence lower than 1 × 10^14 ions/cm2 and shows less shift at fluence higher than 1 × 10^14 ions/cm2. The TEM results reveal that the shapes of Ag NPs also show significant deformation at fluence lower than 1 × 10^14 ions/cm2 and show less deformation at fluence higher than 1 × 10^14 ions/cm2. The blue shift of the SPR peak is considered to be the consequence of defect production and Ag NP shape deformation, Based on the thermal spike model calculation, the temperature of the silica surrounding Ag particles first increases rapidly, then the region of Ag NPs close to the interface of Ag/silica is gradually heated. Therefore, the driven force of Ag NPs deformation is considered as the volume expansion of the first heated silica layer surrounding Ag NPs.展开更多
基金Supported by National Natural Science Foundation of China(11105191,91426304)National Magnetic Confinement Fusion Program(2011GB108003)National Basic Research Program of China(2010CB832904)
基金sponsored by the National Magnetic Confinement Fusion Program(No.2011GB108003)National Natural Science Foundation of China(No.U1532262)。
文摘In the present work,the irradiation hardening behavior of a Chinese low-activation ferritic/martensitic steel CLF-1,a candidate for fusion reactor blankets,is studied.Specimens were irradiated with high-energy14N and56Fe ions at the terminal of a cyclotron to three successively increasing damage levels of 0.05,0.1 and 0.2 displacements per atom(dpa)at about-50°C.The energy of the incident ions was dispersed to 11 successively decreasing grades using an energy degrader,thereby generating an atomic displacement damage plateau in the specimens from the surface to a depth of 25μm,which is sufficiently broad for the Vickers hardness test.Eight different loads(i.e.98 mN,196 m N,490 m N,980 m N,1.96 N,4.9 N,9.8 N and 19.6 N)were applied to the specimens to obtain the depth profiles of the Vickers hardness by using a microhardness tester.Hardening was observable at the lowest damage level,and increased with increasing irradiation dose.A power-law correlation of the Vickers hardness with the damage level(HV0=1.49+0.76 dpa0.31)is proposed.Testing with a nano-indentation technique was also performed,and a linear relationship between the Vickers micro-hardness and the nanohardness(HV0=0.83 H0)was observed.A comparison with other RAFM steels(CLAM,JLF-1,F82 H,EUROFER97 etc.)under neutron or charged particle irradiation conditions shows that most of the RAFM steels exhibit similar power-law exponents in the dose dependence of irradiation hardening.The difference in the irradiation hardening may be attributed to differences in microstructure prior to irradiation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11475230 and U1532262
文摘Metallic nanoparticle （NP） shapes have a significant influence on the property of composite embedded with metallic NPs. Swift heavy ion irradiation is an effective way to modify shapes of metallic NPs embedded in an amorphous matrix. We investigate the shape deformation of Ag NPs with irradiation fluence, and 357 MeV Ni ions are used to irradiate the silica containing Ag NPs, which are prepared by ion implantation and vacuum annealing. The UV-vis results show that the surface plasmon resonance （SPR） peak from Ag NPs shifts from 400 to 377nm. The SPR peak has a significant shift at fluence lower than 1 × 10^14 ions/cm2 and shows less shift at fluence higher than 1 × 10^14 ions/cm2. The TEM results reveal that the shapes of Ag NPs also show significant deformation at fluence lower than 1 × 10^14 ions/cm2 and show less deformation at fluence higher than 1 × 10^14 ions/cm2. The blue shift of the SPR peak is considered to be the consequence of defect production and Ag NP shape deformation, Based on the thermal spike model calculation, the temperature of the silica surrounding Ag particles first increases rapidly, then the region of Ag NPs close to the interface of Ag/silica is gradually heated. Therefore, the driven force of Ag NPs deformation is considered as the volume expansion of the first heated silica layer surrounding Ag NPs.
