The paper presents the properties of plastics under the trade names of PMMA and Midas, and of Formowax, Romocast 305 and Romocast 930 casting waxes. Their effect on the quality of foundry patterns used in the manufacture of ceramic moulds for precision casting is also discussed. From the selected materials for foundry patterns, samples were made for testing using the following methods: (i) 3D printing in the case of plastics, and (ii) conventional method based on tooling in the form of metal moulds (dies) in the case of casting waxes.
The most important physico-mechanical properties of materials for foundry patterns were determined, i.e. linear shrinkage, softening temperature, relative elongation and coefficient of thermal linear expansion. Bending tests were carried out on samples of patterns printed and made in metal moulds, including determination of the surface roughness of patterns.
After the process of melting out patterns from the cavities of ceramic moulds in an autoclave, the degree of their melting out was visually assessed (i.e. the residues from pattern removal were evaluated). The ash content after burning out of foundry patterns was also determined. The conducted tests allowed comparing the important parameters of materials used for foundry patterns and assessing the suitability of selected plastics as a material for foundry patterns used in the manufacture of high-quality precision castings.
The paper deals with analysis of samples made of Inconel 718 nickel superalloy, produced using direct metal laser sintering (DMLS), known as “sintering”, and precision casting technologies. The theoretical part is focused on the characteristics of producing samples of the nickel superalloy by modern additive methods (those for processing metallic materials) and by the conventional technology of precision casting. The practical part involves the investigation of the mechanical properties and texture of the surfaces of the tested samples. A significant part of this study is devoted to analysis of fracture surfaces and EDX experimental testing of TEM lamella by using of electron microscopy methods. The conclusions of this paper include a discussion, evaluation and explanation of both technologies applied on tested samples. Finally, the main benefits of using modern additive technologies in the design and production of heat-resistant components of turbochargers are discussed.
The study discusses the issues connected with the production of thin-walled ceramic slurry in the replicast cs technology. In the ceramic mould production process, a special role is played by the liquid ceramic slurry used to produce the first layer of the mould. The study examines selected technological properties of liquid ceramic slurries used to produce moulds in the replicas cs technology. The ceramic slurries for the tests were prepared based on the binders Ludox Px30 and Sizol 030, enriched with Refracourse flour. The wettability of the pattern's surface by the liquid ceramic slurry and the dependence of the apparent viscosity on the ceramic flour content in the mixture were determined. The wettability of the pattern surface by the liquid ceramic slurry was determined based on the measurement of the wetting angle. The angle was determined by means of an analysis of the computer image obtained with the use of a CDC camera.