|Piotr Długosz, Paweł Darłak, Robert M. Purgert, Jerzy J. Sobczak|
The paper presents a method of casting metal matrix composite materials based on light alloys reinforced with cenospheres. The cenospheres, which are product of fly ash processing by flotation, were formed into the porous ceramic shaped elements and subjected to pressure infiltration with liquid metal on a specially designed hydraulic press. Studies have shown that proper selection of process parameters, such as squeeze pressure, temperature of alloy and ceramic preform is necessary to obtain satisfactory properties of the ready composite products.
Keywords: cenosphere, ALFA composites, pressure infiltration,
Download 0.99 MB >>
Franciszek Pezarski, Irena Izdebska-Szanda, Elżbieta Smoluchowska, Roman Świder, Andrzej Pysz
The article presents the results of laboratory tests on the binding characteristics of moulding sands with inorganic geopolymer binders and for comparison with furan resin and alkaline resin, designed for casting of aluminium - based alloys. The carried out investigations have proved, among others, that sands with geopolymer binder are characterised by high strength and permeability and low gas evolution rate. There is real possibility to control the binding rate of these sands through application of appropriate hardener. Sands with geopolymer binder have lower final resistance than furan sands which is beneficial when unburnt sand is knocked out from mould. Simulation studies have proved the usefulness of sands with geopolymer binder in the manufacture of sand moulds and metal
moulds with sand cores for aluminium alloy castings.
Keywords: moulding sands, inorganic geopolymer binders, simulation studies, sand moulds,
Download 1.08 MB >>
Zenon Pirowski, Waldemar Uhl, Jacek Wodnicki, Andrzej Gwiżdż, Krzysztof Jaśkowiec
The Inconel 740 type nickel alloy was melted in a vacuum, medium frequency induction furnace. During melting the inert gas (argon) atmosphere was used Metal was poured into a ceramic mould based on ethyl silicate. Models were 300 mm long rods of 20 mm diameter. Castings were used as a test material to evaluate the structure in as-cast state and after heat treatment and to determine the mechanical properties. The effect of time-temperature parameters of the aging process of an Inconel 740 type alloy on the process of the precipitation and solution hardening was investigated.
Keywords: nickel alloys, heat treatment, mechanical properties, structure,
Download 1.55 MB >>
Jerzy Stachańczyk, Rafał Pabiś
The article presents the developed research methodology that allows the evaluation of the kinetics of solidification and cooling of pattern material in a metal mould ( die). The apparatus was described and the results of investigations carried out on selected pattern materials were presented. The solidification and cooling rate under the variable parameters of a technological process was determined.
Keywords: kinetics of solidification, pattern material, cooling, technological process,
Download 744.1 KB >>