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The electron beam radiation of polymer materials can bring about various property improvements. The interaction between energized electrons and materials result in valuable reaction being crosslinking. These modifications to the molecular structure are characterized by improvements to the mechanical and physical properties of the polymer materials. Polyamide 12 reinforced with glass fiber tested showed significant changes of thermal stability and mechanical properties after electron beam radiation. The increased properties of polymer materials radiated electron beam is helpful in expanding the applications in automotive industry. This paper discusses the technical advantages and target application of the radiation polyamide 12 reinforced with glass fiber.
Wear of glass fiber reinforced polyamide composites for C-EPS (Column-type Electric Power Steering) worm gear is studied. Main focus of this work is given to moisture absorption of the composites and its effect on wear characteristics. Worm gears in 3 different types are manufactured by modifying the injection design using glass fibers and polyamide (PA12). Mechanical properties of the gears, such as hardness and strength, are evaluated first in terms of the orientation of glass fibers in the composite and then tribological properties are examined. The friction and wear of the worm gear was measured by a specially designed friction tester for worm gears, which measures amount of wear and backlash. Results indicate that the worm gear manufactured by the upper injection design shows the lowest backlash increase compared to the other two cases. Amount of backlash is also decreased by using upper injection design in a wide range operation condition. Particularly noteworthy is the finding that the contact angle of glass fiber has a remarkable effect on the wear characteristics.
Tribological properties of glass fiber reinforced polyamide 12 (PA 12) resin are studied by changing the orientation of the fibers and fiber contents in the composite. The friction level and wear amounts are measured using a block-on-disk tester and microscopic interpretation of the friction and wear is given based on the observation of surface topography after tests using an SEM. The results show that PA 12 reinforced with 50% glass fiber manufactured with normal orientation has the best wear resistance with the low friction level compared to the composites with the parallel alignment or other fiber contents. Particularly noteworthy is the finding that the PA 12 with an optimum content of the glass fiber in normal alignment can substitute the PA 66 which has been limited in its application for a worm gear due to moisture absorption.
Objectives: The aim of this study is to identify physicochemical properties such as chemical composition, size, shape and crystal structure of powder byproducts generated from a metallization process and its 1st scrubber in the semiconductor industry. Methods: Powder samples were collected from inner chambers during maintenance of the W-plug process equipment (using tungsten hexafluoride as a precursor material) and its 1st scrubber. The chemical composition, size and shape of the powder particles were determined by field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) equipped with an energy dispersive spectroscope (EDS). The crystal structure of the powders was analyzed by X-ray diffraction (XRD). Results: From the SEM-EDS and TEM-EDS analyses, O and W were mainly detected, which indicates the powder byproducts are tungsten trioxide (WO3), whereas Al, F and Ti were detected as low peaks. The powder particles were spherical and nearly spherical, and the particle size collected from the process equipment and its 1st scrubber showed 10-20 nm (agglomerates: 55-90 nm) and 16-20 nm (agglomerates: 80-120 nm) as primary particles, respectively. The XRD patterns of the yellow powder byproducts exhibit five peaks at 23.8 33.9 41.74 48.86 and 54.78 which correspond to the (200), (220), (222), (400), and (420) planes of cubic WO3. Conclusions: We elucidated the physicochemical characteristics of the powder byproducts collected from W-plug process equipment and its 1st scrubber. This study should provide useful information for the development of alternative strategies to improve the working environment and workers`` health.
Wear characteristics of two different Polyamides (PA66 and PA6l2) for worm gears were studied using a block-on-ring friction tester. The friction coefficient, weight loss, and wear scar width were measured during friction tests and surfaces were examined using an optical profiler and SEM. Results showed that viscosity had a significant influence on friction coefficient and wear performance. The worm gear with lower viscosity showed lower friction coefficient and better performance in wear resistance. The wear mechanism of the two polyamides was discussed considering the transfer of polymer to steel surface.