Primena metoda inverznog inženjerstva u cilju pronalaženja graničnih uslova pri livenju u peščanim kalupima

Abstract

U disertaciji je razvijena nova eksperimentalna postavka za merenje graničnih uslova pri livenju u peščanim kalupima. Utvrđeno je da se uvođenjem pojma prividne toplotne difuzivnosti materijala kalupa može poništiti greška pozicioniranja termoparova i time smanjiti greška procene graničnih uslova. Dodatno, pokazano je da proces izdvajanja intermetalnih jedinjenja tokom procesa očvršćavanja kalupa može uticati na vrednosti graničnih uslova. Razvijena je i nova empirijska korelaciona funkcija kojom se može opisati promena vrednosti koeficijenta prenosa toplote između kalupa i odlivka.

In this study a new experimental technique and apparatus for estimation of boundary conditions in sand casting process were developed. It is shown that thermocouple positioning errors can be nullified by introducing a concept of apparent heat diffusivity of the mold material. In this way, total error of the heat transfer estimation can be reduced. Additionally, it was found that the process of precipitation of intermetallic compounds can influence the value of achieved metal-mold heat transfer. A novel empirical correlation function is proposed. This function has the ability to accurately describe the change in interfacial heat transfer with the casting surface temperature.