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ABSTRACT The polyimide (PI) composites reinforced with carbon fibers, glass fibers, and aramid fibers were fabricated by means of a hot-press molding technique and irradiated by electron or proton for a certain time. The friction and wear behavior after irradiation, sliding against GCr15 steel balls, were evaluated in a ground-based simulation facility using ball-on-disk tribosystem. The change of the chemical composition of the radiated surface was examined by X-ray photoelectron spectroscopy. The worn morphologies and radiated surfaces of the materials were observed by scanning electron microscope to reveal the wear mechanism. Experimental analysis indicated that the chemical composition of the materials changed and an irradiated layer was formed at the surface. This irradiation layer had an important effect on the friction and wear behavior of the PI composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40774. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the effect of short carbon fiber (SCF), graphite (Gr) and nano-Si3N4 on the friction and wear behavior of polyimide (PI) composites were studied using a block-on-ring arrangement. Experimental results revealed that single incorporation of SCF and Gr can improve the friction-reducing and anti-wear abilities of the PI composites significantly. However, nano-Si3N4 deteriorated the wear resistance of the PI composite drastically as single filler. A synergistic effect was found for the combination of nano-Si3N4 and SCF and Gr, which lead to the best tribological properties. It also can be found that the filled PI composites exhibited better tribological properties under higher PV product (the product of load and sliding speed). Moreover, the filled PI composites showed better tribological properties under oil lubrication and worse tribological properties under water lubrication compared with that under dry sliding condition. [Copyright &y& Elsevier]

Abstract: To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved the adhesion between the fiber and phenolic matrix and hence to improve the friction-reduction and anti-wear properties of the CFRP composite. [Copyright &y& Elsevier]

The poor interfacial compatibility between functional fillers and matrix greatly restricts development of polymer composites. Therefore, in the present paper, carbon fibers (CFs) were modified by biomimetic polydopamine (PDA) and amino silane (KH550) to improve interfacial bonding strength with epoxy (EP) substrate. The grafting of PDA and KH550 was divided into "PDA", "PDA-KH550" and "(PDA + KH550)" methods for regulating interfacial compatibility and exploring the reaction mechanism. Improved interfacial strength was beneficial to transfer stress from the matrix to fillers. Consequently, mechanical properties of modified CF/EP were obviously superior to those of unmodified EP/CF. Besides, wear resistance of EP/CF-(PDA + KH550) had an increase of 76%, 67%, 60% and 49% compared to that of EP, CF/EP, CF-PDA/EP and EP/CF-PDA-KH550. Image 1 • PDA and KH550 were used to regulate interfacial compatibility of CF and EP. • The different reaction mechanisms of PDA and KH550 were explored. • The tribological mechanism of modified CF/EP were systematically analyzed. • "CF-(PDA + KH550)" method significantly improved simultaneously the mechanical properties and wear resistance. [ABSTRACT FROM AUTHOR]