Properties of Carbon Fiber Reinforced Poly(vinylidene fluoride)-Based Friction Materials of Ultrasonic Motors

In order to improve output properties and antiirradiation capability of ultrasonic motors (USMs), which are driven by friction forces of friction material between the stator and rotor, a type of friction material is fabricated by composite materials consist of carbon fiber (CF) and polyvinylidene fluoride (PVDF). The effects of different contents of CF on the mechanical and tribological properties of PVDF-based friction materials are studied, and the mechanical features of the relative USMs are measured. Further, the worn surface morphology of PVDF composites is observed by means of scanning electron microscope and the wear mechanisms are also discussed. In addition, the antiirradiation capability of the type of friction materials is measured by the gamma-ray irradiation at room temperature environment with the total radiation dose of 4.0X rad (Si). The experimental results show that the incorporation of CF into PVDF can effectively improve the friction and wear properties of the friction materials, and the mechanical properties of TRUM-60 used by relative PVDF composites are also increased with the increase of CF. For TRUM-60, both the no-load speed and holding torque of the USMs were high, and the wear of friction material was lowest, when the CF content is 15 wt%. The experiment results also show that this PVDF-based friction material has a good antiirradiation property. Therefore, the composite materials consist of CF and PVDF are beneficial for the applications in USMs, especially for some radiation environment. (C) 2014 Society of Plastics Engineers