College - Author 1

College of Engineering

Department - Author 1

Materials Engineering Department

Degree Name - Author 1

BS in Materials Engineering

College - Author 2

College of Engineering

Department - Author 2

Materials Engineering Department

Degree - Author 2

BS in Materials Engineering



Primary Advisor

Blair London, College of Engineering, Materials Engineering Department


In order to automate the vacuum induction melting of B1900 nickel-based superalloys, a procedure that minimizes the number of ceramic inclusions must be developed. The primary mechanism for inclusions is suspected to be the melt bath agitation eroding the ZrO2 refractory crucible. As such, various furnace parameters of time and power were tested in order to observe their effect on the presence of ceramic inclusions. Four different sets of parameters were tested. The parameters are divided into four parts: initial heating, temperature stabilization, final heating, and target temperature acquisition. The parameters were developed by analyzing a preliminary set of melts. The analysis of the preliminary melt pyrometer data found where the temperature increases in the furnace started to slow, identified by a point of inflection. At these points the power was increased to prevent temperature drop. This method produced melt curves with significantly reduced temperature drops and superheating. Each given melt produced eight tensile test bars and eight hardness testing tabs. The ceramic inclusions were evaluated using a penetrant and developer inspection followed by microscopy. Sherwin HM-604 fluorescent dye penetrant and Sherwin D100 developer were used to observe the presence of ceramic inclusions A 365 nm ultraviolet light was used in order to identify the location of ceramic inclusions within the samples. The inclusions were imaged analyzed with an Olympus SZX16 stereomicroscope. The damaging inclusions were counted and the numbers of inclusions among trials were compared in order to evaluate which set of parameters best reduces the number of significant ceramic inclusions. Overall, the modified set of parameters using the heating points of inflection had relatively few ceramic inclusions with most being of an insignificant size. However, 3 inclusions larger then 330um were observed with the majority being present when the power was held at 85kW for 90s. From the results, it was observed that a relatively higher power and a shorter duration in the second step allows for cleaner and more efficient melts. This was demonstrated in the performance of a 60s second step at 85kW. The trial had the fastest time to pour temperature at 330s with no inclusions above 330um in size.

Available for download on Friday, June 11, 2027