ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The mechanical behavior of mixed α′/β′-SiAlON materials was studied at elevated temperatures. Two different α′/β′-SiAlON compositions along the Si3N4-Y2O39AlN composition line in the Si3N4-Al2O3AlN-YN3AlN plane (α′-SiAlON plane) were prepared using three different raw-material mixtures. Six different materials were obtained with significantly lower values in α′-SiAlON than expected. The high-temperature properties of the materials studied were influenced strongly by the chemical composition (α′ content and grain-boundary phase) of the SiAlONs. A high content of α′-SiAlON was beneficial in terms of creep behavior of the materials. The same materials, however, were characterized by a considerably degradated fracture behavior at elevated temperatures in air because of a crack-growth process enhanced by the poor oxidation resistance of these materials. It was concluded that, despite some superior features of the materials studied, a long-term application of mixed α′/β′-SiAlON materials at 1400°C in air is problematical. A combination of all properties required for such applications was not observed. For that reason, it is suggested that the real high-temperature potential of these materials in air should be limited to temperatures 〈1300°C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.1998.tb02461.x
Permalink