11 research outputs found
Implementation and Evaluation of a Spectroscopic System for Passive Near-Field Microscopy
Formation of boehmite crystals on microblasted aluminum surface to enhance performance of metal–polymer direct joining
Effect of delays in softness display using contact area control: rendering of surface viscoelasticity
Effects of molding conditions on injection molded direct joining using a metal with nano-structured surface
Total arch repair with frozen elephant trunk using the “zone 0 arch repair” strategy for type A acute aortic dissection
Positron Annihilation Lifetime at Defects in Metals
Since positron annihilation measurement is very useful to the study of defects in solids, many investigations have so far been performed for various crystals, especially metals and alloys. Atomic and electronic structures of various defects are, however, very complicated and have not been fully clarified yet and more detailed experiments and precise calculations are still needed. Vacancy and its clusters, dislocations and precipitates are main objects so far investigated and in this paper recent experimental and calculational results for vacancies in Fe and Fe-alloys and dislocations in Ni and Fe are described. Positron annihilation lifetime measurements for high-purity Fe and Fe-alloys irradiated with electrons at low temperature showed the fundamental behaviour of vacancies and the interaction between a vacancy and alloying elements, It was made clear that vacancies in Fe become mobile above 200K in Fe, but in the presence of various alloying elements the interaction behaviour between vacancies and alloying elements became important. Deformed Ni and Fe usually showed intermediate lifetime component between matrix and a vacancy. Positron lifetime calculation showed that this intermediate lifetime component does not correspond to a straight dislocation, but vacancies trapped at dislocation lines
金属中の格子欠陥における陽電子消滅寿命
Since positron annihilation measurement is very useful to the study of defects in solids, many investigations have so far been performed for various crystals, especially metals and alloys. Atomic and electronic structures of various defects are, however, very complicated and have not been fully clarified yet and more detailed experiments and precise calculations are still needed. Vacancy and its clusters, dislocations and precipitates are main objects so far investigated and in this paper recent experimental and calculational results for vacancies in Fe and Fe-alloys and dislocations in Ni and Fe are described. Positron annihilation lifetime measurements for high-purity Fe and Fe-alloys irradiated with electrons at low temperature showed the fundamental behaviour of vacancies and the interaction between a vacancy and alloying elements, It was made clear that vacancies in Fe become mobile above 200K in Fe, but in the presence of various alloying elements the interaction behaviour between vacancies and alloying elements became important. Deformed Ni and Fe usually showed intermediate lifetime component between matrix and a vacancy. Positron lifetime calculation showed that this intermediate lifetime component does not correspond to a straight dislocation, but vacancies trapped at dislocation lines