For polymer composites, interfacial crystalline structures retain an important role in the macroscopic properties and are significantly affected by the processing conditions, such as the temperature, time, and external field. In this study, the transcrystallization behavior of the carbon nanotube fiber and isotactic polypropylene composite was investigated by polarizing light microscopy. The influence of the formation of the transcrystalline layer on the interfacial adhesion was evaluated by a single-fiber fragmentation test. The results show that the growth rate of the transcrystalline layer was strongly influenced by the isothermal crystallization temperature, and the interfacial shear strength was markedly enhanced by the formation of the layer. The interfacial adhesion was further increased with the gradual perfection and growth of transcrystallinity.

This study discusses the mechanical and tribological properties of a series of carbon nitride coatings deposited by unbalanced DC magnetron sputtering using nitrogen-argon mixture gas and graphite targets. The carbon nitride coatings were with varying carbon/nitrogen ratio by varying the gas flow rate ratio of nitrogen gas/argon while kept the overall gas flow rate at constant. The carbon nitride coatings with C/N ratios from 2.01 to 3.27 were obtained. The coatings were characterized and studied by nanohardness, scratching, and wear testers. It was found that the carbon nitride coatings with C/N ratio=2.36 showed the best performance of all the evaluated properties.

Amorphous carbonitride coatings (a-C:N and a-C:N:H) with dopant of niobium (Nb) were deposited on substrates of JIS SKH51 high speed steel (HSS) by a four-target close-field unbalance magnetron sputtering system. Subsequently, they were characterized by GDOS, XRD and XPS, and their corrosion resistance was comparatively evaluated. An electro-chemical tester was used to evaluate the corrosive behavior. An SEM was used to examine the test surface. The results revealed that the Nb dopant provided improvements in the corrosive performance to both the a-C:N and a-C:N:H coatings.

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