Metallurgy and Foundry Engineering
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ISSN 1230-2325
e-ISSN: 2300-8377
Issue Date
2011
Volume
Vol. 37
Number
No. 1
Description
Journal Volume
Metallurgy and Foundry Engineering
Vol. 37 (2011)
Projects
Pages
Articles
Forming of the microstructure in Fe-C-V alloys
(2011) Kawalec, Magdalena; Fraś, Edward
The study presents the results of microstructural examinations of the volume solidifying Fe-C-V alloys containing carbon in the range of 1.45-2.23% and vanadium in the range of 7.33-15.08%. Attention was focussed on near-eutectic alloys. The Fe-C-V eutectic crystallising in these alloys is composed of ferrite and vanadium carbides of VC1-x type, and as such is included in the group of fibrous eutectics. During research, the experimental eutectic lines were plotted for Fe-C-V alloys, and a formula enabling calculation of the eutectic saturation ratio of these alloys was proposed.
Decorative layers on silicon bronzes
(2011) Muskała, Karolina; Nadolski, Maciej; Derda, Anna
Decorative coatings artificially obtained on the surfaces of copper castings, commonly called artificial patinas in opposition to natural patinas, allow for adjusting the colour, the gloss, and the colour intensity of a casting to the customer demands. A decorative coating is a part of the artistic casting and the key element to the impression exerted by a sculpture. The colour, the type, and quality of a decorative coating depend on the author's intention, so that an artistic foundry should deal successfully with a variety of demands. Beside exerting the strictly artistic impression, patinas have one more goal to achieve - it is the corrosion protection. Natural patinas arising nowadays are characterised by Iow quality, irregular thickness, numerous cracks, and the dull taupe-brown colour. Therefore there exists need of generating decorative coatings in a controlled way. The present work is aimed to determine the influence of mechanical abrasive working applied to the surfaces of BK331 silicon bronze castings on the quality and durability of the obtained decorative coating for given recipes for patinating solutions.
The influence of the Glassex additive on technological and knock-out properties of the moulding sands with hydrated sodium silicate and new ester hardeners
(2011) Major-Gabryś, Katarzyna; Dobosz, Stanisław
The article takes into consideration the researches concerning inserting the Glassex additive to the moulding sands with water glass and the new ester hardeners. The investigations combine the works connected to the Glassex additive influence on the moulding sand's with water glass knock-out properties and the works connected to the elaboration of the new ester hardeners upgrading of ability to mechanical reclamation of the moulding sand with water glass.
Drying and hardening of ceramic moulds applied in the investment casting technology - investigations of the process kinetics
(2011) Zych, Jerzy; Snopkiewicz, Tomasz
Ceramic moulds applied in the investment casting technology are multilayer structures, built in an alternating process of depositing and drying of successive layers. Each individual layer is formed from a fluid (liquid) ceramic moulding sand and a grain matrix. In the current, environmentally technology fluid ceramic sands based on ethyl silicate are being substituted by ceramic sands containing colloidal silica as a binder. The ability and rates of drying and hardening of these new colloidal (water) ceramic moulding sands are quite different than of the ones which have a binder dissolved in alcohol. The kinetics of the process based on new binders is not well known. The technological principle requires that the successive layer deposition is done only when the one deposited previously is already sufficiently dry. Investigations of the possibility of application of some methods including: ultrasound, resistance and weigh method are presented in the paper. Advantages and disadvantages of each method are indicated as well as the assessment of their practical suitability is perfomed.
Dependence of tensile wet strength from regeneration time and grain size of the matrix ceramic moulds
(2011) Kamińska, Jadwiga; Kolczyk, Joanna; Żymankowska-Kumon, Sylwia
Production technology of nwestment casting involves transmitting the elements of shape, dimensions and properties by filling in the appropriate liquid metal ceramic forms reproduced by a model made of wax removed by melting it. The manufacturing process of inwestment casting in the lost wax technology consists of a number of technological operations: preparing of wax models and their assembling in the model units, the preparation of ceramic mixture, successive layers of debris, wax melting in an autoclave, drying the samples at 100 °C, heating the samples at temperatures ranging from 400 to 700 °C. So far, the technology was based on the use of ceramic mixture, which the bond was hydrolysed ethyl silicate. Currently, due to environmental protection and improvement of working conditions, more and more binders with alcohol is replaced with an aqueous solution of colloidal silica. In the study, to create the individual layers a ceramic form, used regenerated ceramic mixture derived from foundry and green ingredients. The regeneration time was respectively 5 and 15 minutes. Used ceramic moulds after mechanical reclamation was given to sieve analysis to determine the grain size (di). Grain sizes 0.2, 0.4 and 0.63 mm were used for the coating of ceramic moulds. The paper presents results of research aimed at the determination of the relationship between tensile wet strength and grain size of ceramic mould: Rm = f[dL). Tests were conducted on cylindrical samples, which deposited the layers of reclaimed ceramic material.