Search results1 – 3 of 3
In this chapter, the authors provide a historical overview of the development of comparative and international education in North America from 1920s to the beginning of…
In this chapter, the authors provide a historical overview of the development of comparative and international education in North America from 1920s to the beginning of the twenty-first century. The authors document the significant role some of the most influential leaders played to help lay the foundation for comparative education societies in Canada, Cuba, Haiti, Mexico, and the United States. Using historical comparative research technique, the authors examine the many interconnections of current and past leaders. The authors conclude with recommendations on how knowing the history can help strengthen comparative and international education development well into the future.
The aim of the present paper is to investigate the mechanical performance of multi-layer films. With the wide application of optic and electronic thin-films, membrane…
The aim of the present paper is to investigate the mechanical performance of multi-layer films. With the wide application of optic and electronic thin-films, membrane materials and membrane technology have become one of the most active fields of research in contemporary materials science (Dumont et al., 1997). Multi-layer films have evolved as candidates for these applications because of their unique properties. TiN and Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. A nano-indentation tester and electronic film distribution tester were utilized to evaluate the mechanical properties and residual stress of the films. The existence of interface effects on the mechanical properties and corrosion resistance of the films were analyzed.
In this study, the Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. The films were deposited on polished 45# steels. Ti was used as the sputtering target. Ar and N2 were applied as working and reactive gases, respectively. Surface morphology was measured using transmission electron microscopy. The composition was analyzed using D8 X-ray diffraction. Nano-indentation tests were performed using Nanoindenter G200 with a Berkovich indenter. A BGS 6341 electronic film stress distribution tester was used to measure the distribution of stress in the films.
The film surface was very smooth and the structure was very dense. The elastic modulus and micro-hardness of Ti/TiN multi-layer films were smaller, compared to those of the TiN film. Furthermore, both of these parameters initially decreased and later increased, with a decrease in the modulation period. The residual stress in the film was compressive. The corrosion resistance properties of TiN films were the best in NaCl solution, less so in alkaline solution and worst in acid solution. For the Ti/TiN multi-layer films tested in an acid medium, the corrosion resistance performance was better when the modulation period was decreased to micron grade under exposure conditions at ambient temperature.
In the present paper, the Ti/TiN multi-layer films were fabricated using PVD with different variations, and the influence on the performance of Ti/TiN multi-layer films due to each single layer period of TiN was studied. The findings should provide useful guidelines for the preparation of high quality Ti/TiN multi-layer thin films.