This paper presents results of a research on the possibilities of applying 3D printed casting models for small production series as alternative to traditional tooling production on automated DisaMatch mould production lines. The main task was to verify and compare the dimensions of the 3D printed models before and after moulding process. The paper discusses main advantages and disadvantages of the 3D printing methods used like FDM (Fused Deposition Modeling)/FFF (Fused Filament Fabrication), SLA (stereolitography) and DPP (Daylight Polymer Printing). Measurement of casting model outside dimension change resulting from moulding sand friction on their surface was made with the use of GOM INSPECT software on the basis of 3D scans made with ATOS TripleScan optical scanner. Hardness of 3D printed models made of ABS, Z-ULTRAT, three different photopolymer resins (from FormLab and Liquid Crystal companies) was verified. The result of the research printed models usability for the foundry industry was presented.
Simplifications used in simulation program codes require the use of substitute parameters in the material databases (also called apparent or substitutive). On the one hand, they formally fit into the records used in the heat flow model, porosity, properties etc. and on the other hand they should be determined in conditions most similar to the real casting-mould system. The article presents results of a research on thermophysical parameters of gypsum mould used for precision casting moulds. Experiments were carried out on a cylindrical mould made of Plasticast gypsum, in which the heat source was a cylinder filled with liquid aluminium alloy of the temperature of 655°C. Energetic validation was carried out by using the NovaFlow&Solid ver. 6.3 simulation code. As a result of validation tests, substitute thermophysical parameters of gypsum were determined. For determined parameters, best-fit of solidification time from the experiment and simulation was obtained and the curves of gypsum mass heating were satisfactorily recreate.
During design of the casting products technology, an important issue is a possibility of prediction of mechanical properties resulting from the course of the casting solidification process. Frequently there is a need for relations describing mechanical properties of silumin alloys as a function of phase refinement in a structure and a porosity fraction, and relations describing phase refinement in the structure and the porosity fraction as a function of solidification conditions. The study was conducted on castings of a 22 mm thick plate, made of EN AC-AlSi7Mg0,3 alloy in moulds: of quartz sand, of quartz sand with chill and in permanent moulds. On the basis of cooling curves, values of cooling rate in various casting parts were calculated. The paper also presents results of examination of distance between arms in dendrites of a solid solution α (DASL), precipitations length of silicon in an eutectic (DlSi) and gas-shrinkage porosity (Por) as a function of cooling rate. Statistical relations of DASL, DlSi, Por as a function of cooling rate and statistical multiparameter dependencies describing mechanical properties (tensile strength, yield strength, elongation) of alloy as a function of DASL, DlSi and Por are also presented in the paper.