Association of major earthquakes (magnitude >= 6 Richter scale) with geomagnetic activity index KP during the period 2001-2007

A critical study of variation of geomagnetic activity index Kp for the period 2001-2007 have been made and its close association with major earthquakes (magnitude >= 6 Richter scale) is presented. From statistical analysis it is confirmed that when Kp touches 0 or 0+ values, major earthquakes take place within 48 hours. This is also explained considering the motion of the molten metal inside the outer core of earth.

PENGARUH TEMPERATUR TUANG TERHADAP POROSITAS, STUKTUR MIKRO DAN KEKERASAN DARI ALUMUNIUM RONGSOK VELG MENGGUNAKAN PENGECORAN EVAPORATIF

The second largest metal material used after steel is Aluminum and its alloys. Ranging from aircraft bodies, vehicles, engine components, ship components, to buildings and very diverse applications using aluminum alloys. Material for making alloy wheels for components in motors using one of the special aluminum alloy applications with regard to the strength and hardness of high-quality aluminum alloys. Industrial companies that make aluminum doors, including windows and frames, make aluminum shelves, storefronts and other products. Produce waste remnants of used aluminum which can be used as aluminum as the main material destination. To reduce the company's production costs, many of them use aluminium scrap as their main casting material. Casting uses a temperature of 650 ° C, 700 ° C, 750 ° C, 800 ° C including casting type evaporative or casting using Styrofoam. The missing styrofoam casting pattern is a casting that uses a pattern of material that can evaporate when exposed to molten metal heat. The casting temperature results can affect microstructure, hardness, porosity and structure.

Casting of Wire Using a Twin Wheel Caster

A twin-wheel caster for casting thin aluminum alloy wire was designed, assembled, and tested. Molten metal was ejected from the nozzle (cross-sectional area: 4 mm2) of a crucible into a triangular groove that was machined on the outer surface of the lower wheel. The metal was solidified by the upper and lower wheels. Wire made of Al-1.2%Fe or 6061 aluminum alloy, whose cross-sectional area was smaller than 20 mm2, could be cast at a speed of 6 or 7 m/min. The upper and lower wheels were made of copper to increase the cooling rate. The diameter of the upper and lower wheels was 200 and 600 mm, respectively. The thickness of the wheels was 10 mm.

Mixing, Mass Transfer, and Numerical Models

We want to eliminate dissolved impurities to another phase: slag, gas, solid, or a molten metal that has limited solubility in the main metal. The various phases may be in the form of droplets, bubbles, particles, or walls. The contact areas with metal should be large. The aim in reactor design and operation is to achieve relatively high velocities and small dimensions. Relations for mass transfer are also included since the behaviour of systems with molten metals may be different from that usually treated in chemical engineering. In the field of turbulence the Prandtl eddy length is important for describing removal to walls. Hydrogen in aluminium and the pick-up of hydrogen in aluminium from water vapour is studied in some detail, measured, and modelled. It is taken into account that hydrogen gas is two-atomic. The approach concerning aluminium may be applied to a range of metals.

GAS-DYNAMIC EFFECT OF THE ARC ON THE METAL OF THE WELD POOL DURING NON-CONSUMABLE ELECTRODE WELDING (REWIEW)

Based on the analysis of the literature data, the influence of the composition of the shielding gas, the voltage across the arc, the current strength on the power (gas-dynamic) effect of an arc discharge with a non-consumable electrode, the thickness of the liquid layer of the molten metal, and the depth of the crater of the weld pool are shown.

Porosity formation studies in high pressure die castings of Al-9Si-3Cu alloy based on Taguchi method

PurposeNowadays, ample industries are fascinated to look for high strength and light weight materials for the development of robust parts. Because of light weight and high stiffness to weight ratio; usage of aluminum parts is growing rapidly, especially in automotive engineering. Process improvement of Al alloys and their grain structure refinement is the current area of interest in casting companies. In this research work, an investigation has been carried out to enhance the process improvement of die casting by optimization of various significant parameters and their refinement of grains by the effect of Nb-C novel grain refiner.Design/methodology/approachL27 orthogonal array (OA) has been considered to optimize the preferred casting input parameters such as molten metal temperature (°C), die temperature (°C), injection pressure (bar), Al-3.5Nb-1.5 C novel grain refiner and Ni alloying additions as key process parameters in order to increase the quality and efficiency of Al-9Si-3Cu aluminum alloy die casting by reducing the porosity formation.FindingsIt was observed that the porosity values have significantly decreased from 0.88% to 0.25% particularly at 0.1 wt.% of new grain refiner and 0.5 wt. % of Al-6Ni master alloy. As per the ANOVA results, it was observed that Al-3.5FeNb-1.5 C grain refiner (F value 2609.22), Al-6Ni alloying addition (F value 1329.13), molten metal temperature (F value 1002.43) and, injection pressure (F value 448.06) are the factors that significantly affects the porosity, whereas die temperature was found to be insignificant. The results show that new grain refiner is one the most significant factor among the other selected parameters. The contribution of the new grain refiner to the variation of mean casting porosity is around 57.74%. confidence interval (CI) has also been estimated as 0.013 for 95% consistency level to validate the predicted range of optimum casting porosity of aforesaid alloy.Originality/valueTo the best of the authors' knowledge, no study has been conducted in the past to investigate the combined effect of these die casting parameters and composition factors for the development of Al-Si robust cast parts. The paper represents original research and provides new information for the fabrication of die casting parts.