Cordierite ceramics for applications in foundry practice

The research of new ceramic coatings has an important role in the improvement and development of new casting methods, especially casting with meltable and evaporable patterns. The selection of ceramic materials to be used as refractory fillers, materials for the binding system and additives for maintaining suspension stability, will be carried out in accordance with the casting method selected for the actual alloys and types of castings. The actual importance of these problems is reflected in the fact that the application of quality coatings increases the production efficiency by producing high quality castings, increases the metal yield and eliminates the expensive casting operations-cleaning and machining. Cordierite ceramic are of great importance in modern technology. Standard raw materials, kaolin, talc, MgO, alumina, feldspar were used in the synthesis of cordierite ceramics. Sintered cordierite of the composition 2MgO ? 2Al2O3 ? 5SiO2 was used as a refractory filler in a ceramic coating for evaporative polystyrene patterns in a new casting technology, the EPC Method. Cordierite characterization was carried out by means of X-ray diffraction. The characteristic temperatures for carrying out solid state reactions in the three component system 2MgO ? 2A12O3 ? 5SiO2 were determined by differential thermal analysis in the range from ambient temperature to 1100 ?C. In order to realistically evaluate possible cordierite application in the production of evaporative pattern ceramic coatings, concurrent analyses with a talc-based coating were carried out. Cordierite ceramics have not yet been used in casting. Kordijeritna keramika ima vaznu ulogu u savremenim tehnologijama. Standardni materijali kaolin, talk, MgO, glinica, feldspat bili su korisceni za sintezu kordijeritne keramike. Kordijeritna masa odgovarala je sastavu 2MgO ? 2Al2O3 ? 5SiO2? Sinterovani kordijerit koriscen je kao vatrostalni punioc za keramicki premaz isparljivih polistirenskih modela za novu tehnologiju livenja - EPC metoda. Posto je ovo prvi pokusaj primene kordijerita kao vatrostalnog punioca keramickih premaza u livarstvu, za ocenu mogucnosti koriscenja, vrsena su uporedna ispitivanja sa premazom na bazi talka. Rendgenska strukturna analiza je koriscena za odredjivanje i pracenje faznog sastava. Za ispitivanje karakteristicnih temperatura na kojima se odigravaju reakcije u cvrstom stanju u trokomponentnom sistemu MgO-Al2O3-SiO2 izvrsena je diferencijalna termijska analiza u intervalu od