Preparation of BSAS Powders and Its Effect on Properties of Coatings

• Main Authors: JIAO Chun-rong, JIAO Jian, CHEN Da-ming, WANG Ling
• Format: Article
• Language: zho
• Published: Journal of Materials Engineering 2016-08-01
• Series: Journal of Materials Engineering
• Subjects: plasma spraying; BSAS powder; environmental barrier coating
• Online Access: http://jme.biam.ac.cn/CN/10.11868/j.issn.1001-4381.2016.08.009

BSAS (BaO-SrO-Al₂O₃-SiO₂) powders were prepared by different methods. The characteristics of the powders, their effect on the structures and properties of the plasma-sprayed environmental barrier coatings (EBC) were analyzed. The results show that BSAS powders prepared by powder granulation process have uneven particles and poor fluidity, and the coatings prepared by this method have rough surface and high porosity structure with bonding strength of 24.1MPa. BSAS powders prepared by agglomerate sintered method have smooth surface, good fluidity and high deposition efficiency, while the coating prepared has an uniform structure with few pores and no cracks with the bonding strength up to 29.8MPa and BSAS phase retention rate is 53.2% after spraying,which is the highest among the three kinds of powders. BSAS particles prepared by fused crushed method are dense and irregular, good liquidity and high deposition efficiency, and the coatings prepared by this powders are smooth with very few pores, but there are lots of micro-cracks, and the bonding strength is only 14.2MPa. The coating phase is restructured after spraying, and the BSAS phase retention rate is 20.5%, which can decrease the properties of the coatings at high temperatures. Results show that the agglomerate sintered method simplifies the preparing process of the spraying powders, and by this method, BSAS powders of excellent quality and high phase stability can be produced. Compared with other methods, BSAS powders prepared by agglomerate sintered method is more suitable for plasma spraying.