Understanding Melting operations. (Melting Methods & Materials).
In their paper, "Effect of Temperature on the Friability of Silicon Carbide in the Cupola," (03-038) A.D. Saikia, V.L Richards and K.D. Peaslee, Univ. of Missouri--Rolla, described the effects of the cupola environment on the integrity of silicon carbide briquettes, which are frequently used as charge material.
Samples of three industrial grades of silicon carbide briquettes were fired and ground in a jaw crusher to determine the influence of temperature and composition on friability. It was determined that the friability of the silicon carbide briquettes increased as the silicon carbide content decreased. Friability also increased for all three compositions with increasing firing temperature up to approximately 1832F (1000C), above which friability decreased with increasing temperature.
In his presentation, "Maintaining Crucibles for Steel Investment Foundries," (03-039) K.E. Keyzer, Engineered Ceramics, discussed common crucible failures and their causes in order to develop a list of best practices for steel investment foundries. According to Keyzer, crucible performance is key to a steel investment foundry in order to maximize furnace up time while minimizing slag and inclusions.
Keyzer found that the best ways to prolong the life of a crucible include:
* always install crucible properly, using set procedure and proper tools;
* prevent thermal shock;
* avoid mechanical stress;
* reduce corrosion and erosion.