Papers by Keyword: EDX Analysis

Abstract: The paper deals with the microstructural and chemical analysis of military steel from World War II (WWII). The sample of steel which was found in the form of totally destroyed military armoured transporter from WWII close to Hornad River near Košice city, Slovakia by well-known Slovakian artist Juraj Bartusz in the early 60-ties and nowadays analysed by advanced techniques. Juraj Bartusz created from these pieces of steel cycle of Works under name Forest (1965 – 67) which was exhibited in Paris in Museum Rodin (1968). Steel was non-standardly heat treated by melting during fire of bombs without detonators, pure ecrasite. Thus pieces of steel were exposed to extremely high temperature and change structure. Achieved structure was analysed by optical microscopy (OM) and scanning electron microscopy (SEM) supported by EDX chemical analysis. The layer of corrosion products of this sculpture exposed to rural atmosphere for 58 years in Kosice region was also analysed by both techniques.

Abstract: The work was dealing with direct soldering of Al₂O₃ ceramics and a metal/ceramic composite (MMC) with Al matrix. The joints were fabricated by application of flux-less process by use of a hot plate at the assistance of ultrasound with frequency of 40 kHz. The experiments were performed by use of Zn6Al6Ag solder. Wetting was attained on both substrates. The joints of a good quality were fabricated. The soldering temperature was 420 °C. The microstructural studies of interface have revealed a transient zone of Al dissolving on the side of MMC and formation of Zn oxides on the side of ceramics, which were responsible for bond formation.

Abstract: The most important thing in preparing thin films ceramic material such lead titanate, PbTiO₃ is the behavioral of microstructural changes due to the applying heat treatment during crystallization process. In general, the imperfection of PbTiO₃ surface morphology such as porosity, grain boundaries, existence of microcrack films, films out-diffusion and others are caused by this factor, heat transfer element and found very interesting to be discussed towards next electrical characterization. However, the present study only focuses on the surface morphology of PbTiO₃ thin films that observed by both field emissions scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The details of measurement for observation will be explained later. The preparation of PbTiO₃ thin films were done trough simple sol-gel spin coating method deposited on ITO coated glass substrate.

Abstract: Article deals with the assessment of the properties of ceramic coatings created by thermal spraying technology. Surfaces before coatings deposition were prepared by technology of pneumatic blasting. ZrSiO₄ coating was applied by gas plasma spraying method with NiAl intermediate layer. Mullite coating was applied by water plasma spraying without the intermediate layer and also with NiCr intermediate layer. The quality of the coatings was evaluated by three criteria: adherence of the coatings, REM analysis and EDX analysis. In terms of adhesion of the coatings was found out, that the best properties showed Mullite coating deposited without intermediate layer.

Abstract: Metal foams are widely produced by using different techniques such as compaction and replication method. In this study, slurry method also known as replication method has been used to produce SS316L foams. SS316L powders (50wt% and 60wt%) were mixed with the binders and distilled water by using mechanical stirrer. Polyethylene Glycol (PEG) and Carboxyl Methyl Cellulose (CMC) were used as binders. Polyurethane (PU) foam was used as scaffold and dipped into SS316L slurry then dried in room temperature for 24 hours. Sintering process has been done in two different temperatures which were 1200°C and 1300°C in vacuum furnace. The morphological study was performed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX). The SEM micrograph showed that the cells were interconnected and the structures become denser as the sintering temperature increase. The average pores size is ranging from 252.8 μm-353.8 μm, while strut size ranging from 50.2 μm-79.9 μm based on SEM micrograph analysis. The elemental analysis from EDX showed the element presence in the SS316L foam remain from SS316L powder which are Chromium (Cr), Nickel (Ni), Molybdenum (Mo), Cooper (Cu), Nitrogen (N₂), Sulphur (S) and Silicon (Si). Higher sintering temperature contributes better grain growth between particles where the point-contact between the particles expanded and disappear the small pores.

Abstract: The basic hypothesis of this article focuses on the study changes in the tool wear during drilling of cast iron GTW 35-04. The problem of drilling holes with diameter D=5 to 10 mm resides in the fact that 40 % of these holes do not comply with prescribed requested requirements. This article presents the results of experiments focusing on the study of the damage process in helical drills with diameter d=10.0 mm when drilling into the cast iron GTW 35-04.

Abstract: The basic hypothesis of this article focuses on the study changes in the tool wear during drilling of stainless steels ELC X04Cr18Ni9Ti. The problem of drilling holes with diameter D=2 to 8 mm resides in the fact that 20 to 30% of these holes do not comply with prescribed requested requirements. This article presents the results of experiments focusing on the study of the damage process in helical drills with diameter d=8.0 mm when drilling into austenitic stainless steel ELC X04Cr18Ni9Ti. This study also includes an analysis of accompanying phenomena in the cutting zone by measuring some selected parameters.

Abstract: The aim of this paper is to evaluate the structure of wastes from non-ferrous metals. Wastes from the production of metals were selected namely waste from the production of aluminum - red mud and the waste from the production of nickel - black nickel mud. Morphology of samples was documented by scanning electron microscope, phase analysis using diffraction techniques and the content of elements was determined by EDX analysis. The influence of pretreatment of these wastes on the structure was also investigated.

Abstract: The Ni-4at%W alloys was prepared with cold crucible levitation, subsequent levitation re-melting and high pressure torsion (HPT) intensive deformation. In samples after levitation precipitates of Ni4W phase as well as grain boundary continuous phase were formed. Levitation re-melting resulted in partial dissolution of the precipitates, increasing W content in the matrix and lead to the microstructure refinement. The deformation by HPT, in the range of 300-400%, lead to the lead to the homogenization of the solid solution and partial decomposition of the alloys into pure Ni and W. In the homogenous majority of the sample the microstructure transformed from dendrite microstructure to faceted grains. The analysis of the grains sizes and shapes showed that the average grain size in the sample re-melted by levitation was twice the grain size of the sample only prepared with CCLM. Also, the grains in this sample were elongated by 50-60% in one direction, while in the sample prepared by CCLM they were equiaxial. As the nominal composition of the alloys in both cases was the same, differences observed in the microstructure after re-melting and HPT processing must result only from the differences in the cooling rate leading to small differences in W content in solid solution and phase composition after solidification. High rate of cooling in the levitation methods resulted in Ni4W metastable phase precipitation as well as in the refinement of the microstructure, stronger after additional re-melting of the alloy by levitation.

Abstract: Nickel-base superalloys like Alloy 625 are widely used in power generation applications due to their unique properties especially at elevated temperatures. During the related component manufacturing for gas turbines up to 50% of the material has to be removed by metal cutting operations like milling, turning or drilling. As a result of high strength and toughness the machinability of Alloy 625 is generally poor and only low cutting speeds can be used. High-speed cutting of Alloy 625 on the other hand gets more important in industry to reduce manufacturing times and thus production costs. The cutting speed represents one of the most important factors that have influences on the tool life. The aim of this study is the analyses of wear mechanisms occurring during machining of Alloy 625. Orthogonal cutting experiments have been performed and different process parameters have been varied in a wide range. New and worn tools have been investigated by stereo microscopy, optical microscopy and scanning electron microscopy. Energy-dispersive X-ray analyses were used for the investigation of chemical compositions of the tool's surface as well as the nature of reaction products formed during the cutting process. Wear mechanisms observed in the machining experiments included abrasion, fracture and tribochemical effects. Specific wear features appeared depending on the mechanical and thermal conditions generated in the wear zones.