High density liquid-phase pressureless sintered silicon carbide (LPSSC) bodies were obtained by means of a process which did not require powder bed to protect sample against weight loss. This process was successfully tested with yttria-alumina and yttria-aluminum nitride systems as sintering aids. In both cases, sintered samples showed a fine microstructure with Y4Al2O9 and Y10Al2Si3O18N4 as grain boundary phase, respectively. Sintering behaviour and mechanical properties were examined and compared to other LPSSC-based materials obtained with different sintering processes (hot pressing, gas pressure sintering, pressureless sintering with powder bed). Microstructural analysis confirmed that a glassy-phase scale protects these materials against oxidation up to 1500°C. In this manner we were able to demonstrate that silicon carbide could successfully be sintered by means of liquid phase mechanism also without powder bed. This fact opens liquid phase sintered silicon carbide to a wide range of industrial application.
Properties of liquid phase pressureless sintered SiC-based materials obtained without powder bed
Magnani, G.
2005-06-01
Abstract
High density liquid-phase pressureless sintered silicon carbide (LPSSC) bodies were obtained by means of a process which did not require powder bed to protect sample against weight loss. This process was successfully tested with yttria-alumina and yttria-aluminum nitride systems as sintering aids. In both cases, sintered samples showed a fine microstructure with Y4Al2O9 and Y10Al2Si3O18N4 as grain boundary phase, respectively. Sintering behaviour and mechanical properties were examined and compared to other LPSSC-based materials obtained with different sintering processes (hot pressing, gas pressure sintering, pressureless sintering with powder bed). Microstructural analysis confirmed that a glassy-phase scale protects these materials against oxidation up to 1500°C. In this manner we were able to demonstrate that silicon carbide could successfully be sintered by means of liquid phase mechanism also without powder bed. This fact opens liquid phase sintered silicon carbide to a wide range of industrial application.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
