Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
This master thesis aimed to study thermo-physical properties of greensand molding material depending on different amounts of constituents in the material. Greensand is used in casting industry by most of the world foundries. The thesis work tried to give answer on how bentonite clay, coal dust additive and water content affects the heat transport capacity and which of these ingredients have the highest effect on the thermo-physical properties of greensand. During the work, the calculated properties were also used in numerical simulations of heating curves and compared to the experimentally recorded ones.
Novel Fourier thermal analysis method was used for the first time to study thermo-physical properties of greensand depending on different amounts of bentonite and coal dust additive. By the use of experimental procedure developed by other authors, the thermo-physical properties could be measured and the effect of ingredients investigated in more depth.
During the experimental work, 6 different greensand mixtures with typical parameters used in foundries were prepared and tested by immersing spherical samples in liquid iron and liquid aluminum melts. The heating curves were recorded and further analyzed. The thermo-physical properties were calculated and further investigated and used in numerical calculation to simulate the experimentally recorded heating curves with control volume-based finite difference method in one dimensional spherical coordinates.
The results revealed that the bentonite and coal dust additive increase have the same effect on increase of total absorbed heat by the greensand, however, coal dust additive gives extra functionality to greensand by enabling the greensand to absorb all the heat at lower temperatures compared to greensand with no additions of coal dust additive.
The provided information about the thermo-physical properties of greensand are novel findings to the field of greensand research.
2016. , 59 p.