— The microstructure identification problem is treated : given certain phases in given volume fractions, how to mix them in aperiodic cell so that the effective material constants of the periodic composite lie the closest possible to certain prescribed values ? The problem is studied for the linear conduction équation. It is stated in terms of optimal con trol theory ; the admissible micro geom...

The formation of in situ AlN-TiN-TiB2/Al composite inoculants, which contain multi-phase refiner particles including AlN, TiN, TiB2, Al3Ti, and α-Al, was investigated using nitrogen gas injection. The effects of the main preparation parameters such as nitriding temperature, nitriding time, Ti content in melts, on the microstructure and grain refinement of in situ AlN-TiN-TiB2/Al composite inocu...

In this study, nonlinear vibration of a composite cable is investigated by considering nonlinear stress-strain relations. The composite cable is composed of an aluminum wire as reinforcement and a rubber coating as matrix. The nonlinear governing equations of motion are derived about to an initial curve and based on the fundamentals of continuum mechanics and the nonlinear Green-Lagrangian stra...

Joshi, Aditi S. M.S.M.E., Purdue University, May 2014. Study of Aluminum Honeycomb Sandwich Composite Structure for Increased Specific Damping. Major Professors: Dr. Douglas E. Adams and Dr. J. Stuart Bolton, School of Mechanical Engineering The aluminum honeycomb sandwich composite structure is commonly used in the aerospace and automotive applications where high strength to weight ratio is de...

This study examined the average surface roughness (Ra, microm) of 2 microfilled (Durafill and Perfection), 1 hybrid (Filtek Z250) and 2 packable composite resins (Surefil and Fill Magic), before (baseline) and after eight different finishing and polishing treatments. The surface roughness was assessed using a profilometer. Ten specimens of each composite resin were randomly subjected to one of ...

A novel lamination that consists of aluminum heat spreader plates interspersed with a polymer-based thermal energy storage composite is described. The composite consists of a thermoplastic matrix that encapsulates paraffin such that it is immobilized when in the liquid phase. As a consequence, the thermal energy storage/release process is independent of g-loading or orientation. Composites with...

Typically many grains are averaged to determine strains using X-ray diffraction. In a composite material, however, as the microstructure approaches the fiber diameter, approximations based on a few grains may be misleading. Polychromatic microbeam X-ray diffraction on beamline 7.3.3 at the Advanced Light Source was used to observe relative strain and orientation within hundreds of grains of a m...

in this study, aluminum (al) matrix reinforced with micro-particles (30 µm) and nano-particles (50 nm) boron carbide (b4c) were used to prepare al-2.5%wt., b4c nano-composite and micro-composite, respectively, using mechanical alloying method. the mixed powders were mechanically milled at 5, 10, 15 and 20 hrs. the xrd results indicated that the crystallite sizes of both the micro-composite and ...