The traditional inspection of fittings used in the electrical industry is a cumbersome, dangerous process in terms of safety and operation. However, with the spread of thermography, these tests can be performed simpler, faster, and more safely through electrical connections. This article presents the possibilities, measurement difficulties and the advantages of thermography analysis [1-2].
Ultrasonic welding is very useful for joining thin metal sheets [1, 2]. The effect of ultrasound on microstructure is currently not well understood because the changes produced depend very much on the welding parameters and the properties of the metal being considered. Thin sheets formed by cold rolling acquire a special grain structure. During the welding process the heat produced causes recrystallization; even where heat is not applied in the joining process the recrystallization process alters the mechanical properties within the heat affected zone (HAZ). The mechanical properties of the welded samples depend on the microstructure. In this work we analyse the ultrasonic welding effect on the joint and the HAZ [3, 4].
ZrO2 doped Na-Ba-borosilicate glasses suitable as matrix materials for HLW immobilization were synthesized and corrosion behaviour was investigated in different aqueous media. Hydrolytic stability is increased with the doping level until 5 mol %; above this value the glass vitrification tendency is strongly intensified. Unexpectedly, ZrO2 doping diminished the corrosion stability in 1M HCl solution, and low ZrO2 content showed a low corrosion resistance in 1M Na2CO3 solution also. Doping effect was negligible in case of synthetic seawater. The glass structure is significantly stabilized by the integration of the 30% UO3 added.
The 3D block products presented in this study are used in dental surgery to provide bone replacement for patients who do not possess a sufficient amount of bone tissue for implantation. If dental implants are supported by a proper amount of allografts, the mastication ability of the patient can be totally restored. The required bone replacement for the insertion of dental implants is a reconstruction utilising lyophilized human bone tissue treated with alveolar and mandibular odontological albumin. This study puts emphasis on the analysis, planning and processing of CBCT images, and on the machining and production three-dimensional albumin-coated allograft. The study also extends to former and current bone grafting techniques, and provides a review on BoneAlbumin and the selection of suitable materials. This paper also investigates the domestic and international bone grafting market. Furthermore, it contains a case study and conclusions.
Krisztina Horicsányi, Lilla Asztalos, Dóra Károly and Éva Fazakas
During implantation, stents are delivered in crimped state to the narrowed lesion, where they are expanded to the desired size by the balloon. Due to insufficient size selection or high resistance to plaque, the stent is often widened by the expansion pressure to a level greater than the nominal pressure specified by the manufacturer. Depending on the degree of overpressure, the nominal diameter of the stent may change by several tenths of a millimetre. Numerous studies have dealt with the physiological effects of overexposure and stenogenic stress, but so far no studies have been carried out to investigate the stent coating and corrosion properties of the stent. In our research a widely used drug-eluting, platinum-chromium alloyed steel stent was observed with an inflation pressure of 12 and 18 bar. Scanning electron microscopy revealed lesions of the coating and potentiodynamic tests were performed to determine the corrosion rate.
During our investigation lath martensite was produced in low carbon steels by austenitization at 1200 °C/20 min, and the cooling of samples in ice water. The samples were tempered at a range of temperatures. The tempering effects on microstructure and on mechanical proprieties were investigated. Some samples with lath martensite microstructure were cold rolled and heat treated at different temperatures. Recrystallization was observed after heat treatment at 600-700 °C.
This introductory paper summarizes the characteristics of how “Science” and “Engineering” differ from each other, forming the interdisciplinary topic of Materials Science and Engineering (MS&E). It will be shown how microelectronics has developed from modern materials science, causing a change in paradigm, and how microelectronics has become the “mother” science of informatics, changing life on Earth. To prove the importance of materials, a table is shown summarizing how modern MS&E forms the basis of practically all industries. The situation and development state of MS&E in CEE countries - despite different levels of industrialization – have some characteristics in common, and the way to development might also have techniques in common.
We will also mention the knowledge base that CEE countries possessed during the period of political change, and the likely future that an elderly scientist foresees for the region with the help of young ambitious scientists.
The geometrical modelling of metal foams remains one of the greatest challenges facing researchers in the field. In this paper the analysis of the inner structure of closed-cell aluminium foam - an essential part of the construction of an idealized foam model - is presented. With the application of special purpose software the properties of the foam cells can be mapped precisely and the results applied to the development of idealized foam geometry constructed in CAD applications.
Knowledge of the surface emissivity of metals is becoming more and more important both from the material science, process modelling and control point of view. Previous research results have shown that the emissivity of most metals depends on the temperature of the surface. It has also been reported that the most important temperature region is between 300 – 1000 K degrees, where the change of the emissivity is the most intense, which is also the most significant from a process control point of view . We also report temperature dependent emissivity observed during plasma nitriding of low alloy steels . Related to one of our present research topics the study of the low alloy aluminum (AlMg1, AlMg3) emissivity has prooven relevant. In this article the developed emissivity estimation model is presented. In the first part a literature overview and the theoretical approach of the new method is discussed, followed by the experimental results for low alloy aluminium emissivity determination and a comparison with the results available in the literature.
A unique method for producing aluminium matrix composite wires is the Blücher’s process, i.e. continuous gas-pressure infiltration. An essential condition of the process is that the fibre roving of the reinforcing fibres can be pulled across the orifices of the gas-pressure system with the least damage. The article describes a new test procedure that is capable of characterizing this essential functional property of the ceramic reinforcing fibres in a manner comparable and quantitative.