|Krzysztof Wańczyk, Marcin Małysza, Marek Wawrylak|
The paper presents an attempt to assess the mechanical properties of high-strength AlZnMgCu aluminium alloy samples cast in gypsum moulds. The first stage of the study involved the use of computer simulations to select the optimum sample assembly structure. To this end, the SolidWorks CA D software (assembly geometry design) and Flow3D casting and solidification simulation environment were used. The results are presented as mould cavity filling and cast solidification visualisations. To verify the strength properties of the alloy, strength test samples were prepared. The cast production procedure was repeated for gypsum moulds, which were cooled down to different temperatures after their firing and before filling.
Keywords: mechanical properties, aluminium alloys, gypsum moulds, process simulation,
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Mieczysław Kuder, Adam Żyrek, Adam Bitka, Waldemar Uhl
The paper presents the results of works concerning the optimisation of the process of steel melting for castings of industrial fittings in an induction furnace with an acid lining. Materials containing high activity elements such as Al, Ca, Ti, Zr, Ce, V and Nb were used for deoxidation and modification. The parameters of these procedures were determined on the basis of the results of measurements and determinations of oxygen, nitrogen and hydrogen content at various stages of the process. The quality of cast steel was evaluated on the basis of metallographic, tensile and low temperature impact strength test results. It was found that the measurements of hydrogen content and oxygen activity in the liquid alloy allow for the identification of hazards of the metallurgical process, the development of optimal parameters of deoxidation and modification procedures, the stabilisation of mechanical properties and the avoidance of internal gas type defects in castings.
Keywords: cast steel, gases, modification, deoxidation, mechanical properties, microstructure,
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Robert Żuczek, Stanisław Pysz, Marcin Małysza, Maria Maj
The evolution of the integrated design of engineering processes and structures, including in particular advanced numerical modelling and computer simulations, has enabled a significant shortening of the implementation cycle of innovative material, technological and utility solutions that are essential in projects pursued in the aviation, power and automotive industries.
The use of Integrated Computational Materials Engineering (ICME) has allowed the determination of the latest trends in the use of the process, and the initial identification of the integration methods in the design process of ultra-light, high-strength cast structures using the example of
a brake pedal lever casting. The research concerned design issues aimed at modifying the shape of the cast structure using interrelationships through material testing, modelling processes and experimental tests.
Keywords: numerical modelling, light cast structure, aluminium alloy,
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Rudolf Krzyżak, Piotr Długosz, Paweł Darłak, Sylwia Pawlak
This study was undertaken to recognize sintering-, softening-, melting-, flow temperature, mineralogy, chemistry and prospects for utilization of the Polish fly ashes (FA, FAs). The study is metallurgy-foundry oriented, i.e. it regards the ashes as the (potential) charge material for production the chemical compounds, ceramics, metal-matrix composites (MMC) and ceramic-matrix composites (CMC) and as an item in new technologies. Moreover, definite ashes-derived compounds, e.g. cordierite have been shown to strengthen the metals. A comparison between the ashes and the rocks is drawn, and, comparison between the Polish ashes (type) and those from over-the-world ones is undertaken. The radioactivity of the ashes is addressed as well. 24 (25) samples can be classified into ‘hybrid alumina’ (close to F-class of the ashes), ‘intermediate’ (an Al-analogue to bottom ashes) and calcium-rich ones. Several unique samples, e.g. arcanite-calcite-ettringite- and a bottom ash are outside even this classification. The ‘hybrid alumina’ is knowable by Ca-silicates and Ca-aluminosilicates, the ‘intermediate’ is knowable by anorthite and amphiboles, whereas the calcium-rich ones is devoid of Ca-silicates. Enrichments in toxic elements is addressed and discussed. One of novelties of this paper is that we have encountered the amphiboles, leucite and Fe-Mn phosphates in the ashes - which cannot be regarded as accessory ones. Apart from the ash-Al-alloy pistons, metal-(cenosphere)-ash composites and intimately-intergrown-phase (IPC) composites, a FA-glass-armoured metal is also mentioned. Of the many technologies of the Institute the production of almost pure cordierite (indialite) from fly ash containing moderate amounts of CaO and SO3 is worthy of note. Likewise, MMC- and CMC composites and ceramics thereof are also noteworthy.
Keywords: composite, waste management, fly ash, ettringite, amphibole, cordierite,
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