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A step-by-step procedure to determine the quality of ingots has been developed. This procedure is built on the reduced pressure test and is designed to guide the foundrymen to decide (1) whether the lot of ingots should be accepted and/or (2) what remedial liquid metal processing should be done to bring the melt to the desired levels. A case study on two aluminum alloy A356 ingots is also presented. The results show wide variability in the initial quality of the ingots. Moreover, traditional metallographic techniques to characterize the quality from the slice of the reduced pressure test sample have been shown to provide similar results to those obtained from computerized tomography.

Oxidation creates an important problem with the increasing temperature and additionally if one of the components contains an amount of carbon, then there will be a COxemission risk which has a detrimental effect for the atmosphere. One of the methods to prevent the oxidation of silicon carbide (SiC) is to coat it with Al2O3which has high thermal stability. In this study, the properties of Al2O3coated SiC composite powders were examined to prevent the oxidation of SiC particles by developing a thermal barrier coating and it is aimed to contribute for reducing the gases which make a greenhouse effect and cause global warming. Firstly, boehmite sol was prepared via the sol gel route and then 5 wt% β-SiC (< 100 nm) nanosized particles were added to the boehmite sol and gelation was completed. Alumina coated SiC powders were heat treated at 100, 550, 1,000, 1,300 and 1,600°C under dry air and argon atmospheres. Characterisation analyses showed that alumina coated SiC particles underwent to slightly internal oxidation with the partial oxidation depending on the oxygen ion mobility during the transformation from boehmite to alumina in the interior atmosphere while alumina coated SiC particles gained oxidation resistance against the outer atmosphere.

The Crucible Method is a standard method to determine the corrosion between slag and refractory. According to this method refractory samples are heated to experimental temperature with the active slag powder inside the crucible. The aim of the experiment is to corrode the refractory by slag penetration and cutting the refractory to analyze the corroded surface to determine the slag-refractory interaction. In this study, this method was used and supported by a computer aided surface analyze system which recently has several application areas in material science. The image of the corroded surface of the refractory was transferred to a computer. Image settings and calibrations of complex shaped slag penetration areas were done by Photoshop. Quantitative analysis was done by MVH-ImagePCv7 image analysis software. It was found that the qualitative and quantitative analysis of the Crucible Method was enhanced by the help of computer aided surface display and image analysis techniques.