Microstructure Exploration of the Aluminum-Tungsten Carbide Composite with different Manufacturing circumstances
In the last decade, as demand for high quality materials are increased, the development of lightweight aluminum (Al) also increased especially in aerospace and automotive industries. It has been well known that Al based metal matrix composites (MMCs) offers a very low thermal expansion coefficient, high specific strengths, wear and heat resistance as compared to conventional Al alloys. In order to combine all these properties, MMCs have become a very attractive method for various industrial applications. The interest in Tungsten Carbide (WC) as reinforcements for aluminum (Al) has been growing considerably. Efforts have been largely focused on investigating their contribution to the enhancement of the mechanical performance of the composites. The uniform dispersion of Tungsten Carbide in the Al matrix has been identified as being critical to the pursuit of enhanced properties. In this present research paper emphasis, the effect of Tungsten Carbide content on the Physical properties of the composites like SEM, XRD was investigated. The improvement of physical properties for composites of Al/WC has been compared with pure aluminum.
Characterization of Aluminium reinforced with Tungsten Carbide Particulate and Flyash Metal Matrix Composites
Metal matrix composites are formed by combination of two or more materials (at least one of the material is metal) having dissimilar characteristics. In this present investigation, aluminium (Al 6061) as base matrix metal and tungsten carbide (WC) particulate, fly ash as reinforcements. Fabrication of MMCs was done by stir-casting process. The Tungsten Carbide particulate was added in proportions of 1%, 2%, and 3% and Fly ash was added in proportions of 2%, 4%, and 6% on mass fraction basis to the molten metal. The different combination sets of composites were prepared. Mechanical properties like tensile strength and hardness were studied for both reinforced and unreinforced Al 6061 samples. Microstructure examination was carried by using Scanning Electron Microscope (SEM) to obtain the distribution of tungsten carbide particulate and fly ash in base matrix. From the results, it was found that the tensile strength and the hardness of the prepared metal matrix composites increased with increase in tungsten carbide and fly ash content. The Scanning Electron Micrographs of the samples indicated uniform distribution of tungsten carbide and fly ash particles in the base matrix without voids before testing and with voids after testing. Keywords—Aluminium metal matrix composite, Tungsten Carbide, Fly ash, Stir-casting, Mechanical properties, SEM
A shear instability model of sliding wear
Abstract A model is derived to analyze the conditions under which flat pieces of wear debris are formed by ductile metals during sliding wear. The model assumes that the wear piece contains local planar regions of metal that are more prone to yield than the surrounding material. It is shown that shear occurs preferentially below the surface. Increasing the load leads to the critical condition for shear being satisfied throughout an increasingly wider band of material. At the same time the driving force on the shear plane approaches an asymptotic limit as the load increases.