Yi-qi Wang

Dry sliding wear behavior of Al2O3 fiber and SiC particle reinforced aluminium based MMCs fabricated by squeeze casting method

Al2O3 fiber (Al2O3f) and SiC particle (SiCp) hybrid metal matrix composites (MMCs) were fabricated by squeeze casting method. The tests were carried out using a pin-on-disk friction and wear tester by sliding these pin specimens at a constant speed of 0.36 m/s (570 r/min) against a steel counter disk at room temperature, 100 °C and 150 °C, respectively. To observe the wear characteristics and investigate the wear mechanism, the morphologies of the worn surfaces and specific wear rate were analyzed by using scanning electron microscope (SEM) and Arrhenius plots. Moreover, the effects of fiber orientation and hybrid ratio were discussed.

High-Strength Single-Walled Carbon Nanotube/Permalloy Nanoparticle/Poly(vinyl alcohol) Multifunctional Nanocomposite Fiber.

Magnetic nanocomposite fibers are a topic of intense research due to their potential breakthrough applications such as smart magnetic-field-response devices and electromagnetic interference (EMI) shielding. However, clustering of nanoparticles in a polymer matrix is a recognized challenge for obtaining a property-controllable nanocomposite fiber. Another challenge is that the strength and ductility of the nanocomposite fiber decrease significantly with increased weight loading of magnetic nanoparticles in the fiber. Here, we report high-strength single-walled carbon nanotube (SWNT)/permalloy nanoparticle (PNP)/poly(vinyl alcohol) multifunctional nanocomposite fibers fabricated by wet spinning. The weight loadings of SWNTs and PNPs in the fiber were as high as 12.0 and 38.0%, respectively. The tensile strength of the fiber was as high as 700 MPa, and electrical conductivity reached 96.7 S m(-1). The saturation magnetization (Ms) was as high as 24.8 emu g(-1). The EMI attenuation of a fabric woven from the prepared fiber approached 100% when tested with electromagnetic waves with a frequency higher than 6 GHz. The present study demonstrates that a magnetic-field-response device can be designed using the fabricated multifunctional nanocomposite fiber.

Effect of concentration of ATH on mechanical properties of polypropylene/aluminium trihydrate (PP/ATH) composite

Aluminium trihydrate (ATH) is being extensively added to polypropylene (PP) to make a fire retardant composite. Blends of PP/ATH composite are more fire resistant as compared to pure PP. Percentage proportion of both the constituents in the final composite depends upon the application. Improvement in the fire retardant properties of such composites have been studied and published in literature but effects on mechanical strength have not been addressed. The effect of concentration of ATH on the strength of PP/ATH composite was presented. The tensile, flexural and fracture properties were studied and discussed. Experimental tests, ASTM analytical formulae and finite element approach were used. It has been found that increase in ATH has an inverse effect on the mechanical strength.