Modification of primary silicon was studied in Al-Si hypereutectic alloys with 17 Wt % silicon content. The alloys modified through non-conventional method using oxide addition. The effect of oxide on the morphology and size of Si phases in the hypereutectic Al-Si alloys investigated. The results show that the addition of MnO2 to the hypereutectic Al-Si alloys can modify the primary Si phases. ...

Crystallization of microdroplets of molten alloys could, in principle, present a number of possible morphological outcomes, depending on the symmetry of the propagating solidification front and its velocity, such as axial or spherically symmetric species segregation. However, because of thermal or constitutional supercooling, resulting droplets often only display dendritic morphologies. Here we...

Titanium matrix composites (TMC) represent a perspective materials category with potential applications in many important fields like aerospace constructions, automotive industry, ship structures, sports and households objects, and others. A titanium matrix composite is constituted of a titanium or titanium alloy – matrix and reinforcements materials, which are usually ceramics in form of parti...

The advent of nanocrystalline metal oxide semiconductor permits microheater to be incorporated into integrated gas sensors to heat the sensing layer to a low temperature. The low temperature sensing allows the use of a relatively thin silicon membrane instead of zero Silicon membrane resulting into temperature uniformity across the entire active area (2mmx2mm) which in turn reduces the reliabil...

A magnetic semiconductor/metal nanocomposite with a nanostructured silicon wafer as base material and incorporated metallic nanostructures (Ni, Co, NiCo) is fabricated in two electrochemical steps. First, the silicon template is anodized in an HF-electrolyte to obtain a porous structure with oriented pores grown perpendicular to the surface. This etching procedure is carried out either in formi...

Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450°F (232°C) to about 750°F (400°C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cyl...

Early stage oxidation behavior of SiSiC cellular lattices with different cell types was studied at 1400 °C in two different environments: a porous burner and an electric furnace with stagnant air. Oxidation and silicon alloy bead formation were observed and identified as the most important factors affecting the integrity of the structures. Lowmelting temperature silicon-based alloys formed from...

Glass fibres with silicon cores have emerged as a versatile platform for all-optical processing, sensing and microscale optoelectronic devices. Using SiGe in the core extends the accessible wavelength range and potential optical functionality because the bandgap and optical properties can be tuned by changing the composition. However, silicon and germanium segregate unevenly during non-equilibr...