High-temperature mechanical properties of BN-based composite ceramics

2017-06-01

【Author】 Tian Zhuo; Jia Dechang; Duan Xiaoming; Yang Zhihua; Zhou Yu;

[Institution] School of Materials Science and Engineering, Harbin Institute of Technology;

【Abstract】 The mechanical properties of BN ceramics have been improved due to the introduction of SiO2, but there are still shortcomings of low strength. For this reason, this study will introduce high strength and high modulus SiAlON phase into the matrix as a reinforcing phase. To further improve the mechanical properties of the material. Using BN, SiO2, and AlN as raw materials, a BN-based composite ceramic was prepared using a hot pressing process. Through high-temperature mechanical property testing and scanning electron microscopy (SEM) observation, the impact of the addition of AlN on the high-temperature composite ceramics was studied. The influence of mechanical properties and fracture behavior. Research shows that the high-temperature flexural strength of composite ceramics shows a trend of first increasing and then decreasing with the increase of temperature, and reaches the maximum value at 1300℃, and the increase in strength is mainly due to This is due to the relief of internal stress during the heating process. For composite ceramics with a volume fraction of 5% AlN, the high-temperature bending strength reaches 376.7 MPa at 1300°C, which is an increase of 52.5% compared with the bending strength at room temperature. When the temperature When the temperature rises to 1500℃, its high-temperature bending strength is 272.0 MPa, which has good high-temperature mechanical properties. More reduction

【Key words】 BN-based composite ceramics; SiAlON; high temperature mechanical properties; fracture behavior; flexural strength;

[Fund] National Natural Science Foundation of China Innovation Research Group (51021002); National Science Fund for Distinguished Young Scholars (51225203)