Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7887711 | Ceramics International | 2018 | 6 Pages |
Abstract
Si3N4 ceramic was successfully joined to itself with in-situ formed Yb-Si-Al oxynitride glass interlayer. The joints were composed of three parts: (I) Si3N4 matrix, (II) oxynitride glass interlayer in which hexagonal or fine elongated β-sialon grains and a few ball-like β-Si3N4 grains exist, and (III) diffusion zone in Si3N4 matrix containing a thin dark layer and a ~ 25â¯Âµm thick bright layer. The seam owned similar microstructure to matrix and was inosculated with the matrix as a whole. The strength of the joint tended to increase with the increase of bonding temperature and reached the value of 225â¯MPa, when the joints were prepared at 1600â¯Â°C for 30â¯min under a pressure of 1.5â¯MPa. The high-temperature strength remained 94.7% and 75.2% of R.T. strength when the joints were tested at 1000â¯Â°C and 1200â¯Â°C, respectively. It may be contributed to the high softening temperature of the Yb-Si-Al oxynitride glass phase formed in the seam. Even suffered to the air exposure for 10â¯h at 1200â¯Â°C, the residual strength of the joints was still 143â¯MPa, attributed to the existence of YbAG phase.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Ling Li, Chunfeng Liu, Liangbo Sun, Hongjiang Yu, Xinhua Wang, Xuanzhi Wang, Jie Zhang,