MACHINABILITY OF AISI 410 MARTENSITIC STAINLESS STEELS DEPENDING ON CUTTING TOOL AND COATING

In this study, effects of cemented carbide coated with TiC+TiN, coated with TiC, uncoated and CBN on the machinability of AISI 410 martensitic stainless steel was investigated. In the experiments chip root morphology, cutting forces and surface roughness were determined. Experiments were done in the dry turning conditions. The cutting speed, feed rate and depth of cut were kept constant as, 60 m/min, 0.12 mm/rev and 1.2 mm respectively. Cemented carbide tool coated with TiC+TiN gave maximum cutting forces. Although CBN gave the minimum cutting forces, it was observed that it fractured in a shorter machining length. The optimum values of cutting force and surface roughness were obtained from cemented carbide coated with TiC

Effect of cutting tool materials on surface roughness and cutting forces in machining of Al-Si3N4 composite produced by powder metallurgy

In this study, aluminum-based composites reinforced with various amounts of alpha-Si3N4 were produced by powder metallurgy (P/M). The machinability properties of MMCs were determined by means of cutting forces and surface roughness. Machining tests were carried out by using PCD and K10 cutting tools. Increasing of Si3N4 volume fraction in the matrix resulted in a decrease of the surface roughness and turning forces. PCD cutting tools showed better cutting performance than K10 tools. Surface roughness and turning forces were decreased significantly by PCD tool

Novel synthetic route for growth of gold nanorods via semiconductor procedure

&lt;p&gt;We represent here a novel facile synthesis type route based on semiconductor procedure for growth of gold nanorods GNRs using infinitesimal silicon nanoparticles USSiN. The reaction takes place immediately upon mixing monodispersed hydrogen terminated USSiN of 2.9 nm diameter with auric acid HAuCl4 in presence and in absence of an emulsifier. The resulting colloids have been characterized via scanning electron microscope SEM, Energy dispersive spectrometry EDS and optical microscope OM. Photo-luminesence (PL) measurements have been also carried out. Our results show formation of gold nanorods GNRs, gold nanoplates GNPs, gold nanospheres GNSs and filaments. The formed GNRs have near uniform length of 1.5 µm and diameter of 300 nm (5 aspect ratio). The results are consistent with a seedless process in which the H-terminated silicon nanoparticles act as either the reducing as well as the directional growth agent, eliminating the need for toxic cetyl-trimethyl-ammonium bromide CTAB or, which is typically used as the directional growth agent. &lt;/p&gt;</jats:p

On silicon nanobubbles in space for scattering and interception of solar radiation to ease high-temperature induced climate change

A thin film of silicon-based nanobubbles was recently suggested that could block a fraction of the sun’s radiation to alleviate the present climate crisis. But detailed information is limited to the composition, architecture, fabrication, and optical properties of the film. We examine here the optical response of Si nanobubbles in the range of 300–1000 nm to evaluate the feasibility using semi numerical solution of Maxwell’s equations, following the Mie and finite-difference time-domain procedures. We analyzed a variety of bubble sizes, thicknesses, and configurations. The calculations yield resonance scattering spectra, intensities, and field distributions. We also analyzed some many-body effects using doublets of bubbles. We show, due to high valence electron density, silicon exhibits strong polarization/plasmonic resonance scattering and absorption enhancements over the geometrical factor, which afford lighter but more efficient interception with a wide band neutral density filtering across the relevant solar light spectrum. We show that it is sufficient to use a sub monolayer raft with ∼0.75% coverage, consisting of thin (∼15 nm) but large silicon nanobubbles (∼550 nm diameter), to achieve 1.8% blockage of solar light with neutral density filtering, and ∼0.78 mg/m2 silicon, much less than the mass effective limit set earlier at 1.5 g/m2. We evaluated solid counterpart nanoparticles, which may be produced in blowing/inflation procedures of molten silicon, as well as aging by including silicon oxide capping. The studies confirm the feasibility of a space bubble filtering raft, with insignificant imbalance of the correlated color temperature (CCT) and color rendering index characteristics of sunlight