J. Mater. Sci. Technol. ›› 2014, Vol. 30 ›› Issue (12): 1217-1222.DOI: 10.1016/j.jmst.2014.11.004

• Orginal Article • Previous Articles     Next Articles

Porosity and Oxide Layer Dependence of Thermal Shock Behavior of Porous Silicon Nitride Ceramics

Xuefeng Lu1, Yin Wei1, Hongjie Wang1, Jiangbo Wen1, Jun Zhou2, Jinpeng Fan2   

  1. 1、State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China; 2、National Key Laboratory of Advanced Functional Composite Materials, Beijing 100076, China
  • Revised:2014-08-26 Online:2014-12-20 Published:2015-07-23

Abstract: A water-quenching technique has been adopted to evaluate thermal shock fracture and fatigue behaviors of porous Si3N4 ceramics in an air atmosphere. The high-porosity Si3N4 ceramics exhibit a higher strength retention and a better resistance to thermal shock fatigue because of its role of the pores as crack arresters. A dense and coherent surface oxide layer leads to a significant benefit in residual strength during thermal fatigue, however, an increased fatigue number to 30th cycle cannot cause a further influence although a thicker oxide layer presents, which is attributed to holes defect and disappearance of part intergranular phase.

Key words: Porous silicon nitride ceramics, Oxide layer, Thermal shock behavior, Thermal fatigue