Morphology and Graphitization of the Worn Surface of C/C Composite with Rough Lamination/Smooth Lamination/Resin Carbon as Matrix Precursor

We study systematically the morphology and graphitization of the worn surface of C/C composite with rough lamination/smooth lamination/resin carbon (RL/SL/RC) as matrix precursor tested by using M2000 wear tester with a couple of Cr-coated 40 Cr steel. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses indicate that the worn surface of RL/SL/RC is integrated. Particles with the size of 100~300 nm could be found on the worn surface. The leaning-angles of the particles against the sliding direction on the worn surface are between 30 ° and 50 °. Raman laser spectrum (RLS) analysis reveals that, after the wear test, the graphitization on the worn surface of RL/SL/RC decreased with the increase in load, but graphitization of the fiber kept constant and that of the boundary increased up to 150 N. The surface graphitization of different components became closer and closer with the increase in load.

Characterizations of Liquid Polycabosilane (LPCS) Used as SiC Matrix Precursor for CLVD Process

Characterizations of a liquid polycarbosilane used as SiC matrix precursor were investigated by TG-DTA, FTIR, XRD, etc, which indicated the feasibility of using LPCS as precursor for CLVD process to prepare C/SiC composites. The results show that the inorganic conversion of LPCS to SiC is almost completed at 900 °C, and the crystallization of β-SiC appears at 855 °C approximately. As the temperature increases, the deposit becomes more pure and the crystallinity of β-SiC also increases. The atomic ratio of C/Si in the deposit attained at 1200 °C is near-stoichiometric, the crystallite size of β-SiC is about 33.4 nm.

A Novel Approach For Nanocarbon Composite Preparation

ABSTRACTCarbon nanotubes (CNTs), nanofibers (CNFs) and graphene are promising components for the next generation high performance structural and multi-functional composite materials. One of the largest obstacles to create strong, electrically or thermally conductive CNT/CNF composites is the difficulty of getting a good dispersion of the carbon nanomaterials in a matrix. Typically, time-consuming steps of the carbon nanomaterial purification, ultrasound sonication and functionalization are required. We utilized a new approach to grow CNTs/CNFs directly on the surface of matrix, matrix precursor or filler particles. As the precursor matrix and fillers we utilized cement (clinker), copper powder, fly ash particles, soil and sand. Carbon nanomaterials were successfully grown on these materials without additional catalyst. Investigations of the physical properties of the composite materials based on these carbon modified particles revealed enhancement in the mechanical and electrical properties.