caa a22 4500 477122280 CHVBK 20180405111639.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF03025949 doi (NATIONALLICENCE)springer-10.1007/BF03025949 Study of anisothermal ageing of CANTiM shape memory alloys by positron annihilation [Elektronische Daten] [C. Lam, C. Chung] The thermal-elastic property of high temperature CuAlNiMnTi shape memory alloys was found strongly affected by anisothermal ageing. With slow cycling (cycled at low heating and cooling rates), the transformation temperatures increase with the number of thermal cycle while the transformation enthalpy decreases and finally drop to zero, which indicated a total deterioration of the shape memory effect. Martensite stabilisation was found to be the cause of such deterioration. Positron Annihilation technique was employed to study the properties of the vacancies during the anisothermal ageing process. This was compared with the isothermal aged results. We propose that the changes in the quantity and characteristics of vacancies during anisothermal ageing are only responsible for the kinetics of the martensitic transformation. The result is the shift of transformation temperatures. However, the presence of vacancy agglomerations may have assisted the diffusion of atoms during ageing. Other factors like microstructural changes and atomic reordering will lead to the irreversible martensite stabilisation and make the transformation thermodynamically unfavourable. Springer, 1996 Lam C. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Hong Kong aut Chung C. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Hong Kong aut Metals and Materials The Korean Institute of Metals and Materials 2/2(1996-04-01), 75-80 1598-9623 2:2<75 1996 2 12540 https://doi.org/10.1007/BF03025949 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF03025949 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lam C. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Hong Kong aut NATIONALLICENCE 700 1- Chung C. Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Hong Kong aut NATIONALLICENCE 773 0- Metals and Materials The Korean Institute of Metals and Materials 2/2(1996-04-01), 75-80 1598-9623 2:2<75 1996 2 12540 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer