Preparation and properties of flame-sprayed Mo-FeB-Fe cermet coatings
(1. College of Materials Science and Engineering, Liaoning Technical University, Fuxin123000, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: The powders of Mo2FeB2 cermet were prepared with Mo powders, Fe-B alloy powders and Fe powders as raw materials. Mo2FeB2 cermet coatings were prepared on Q235 steel by reactive thermal spraying (RTS) method and heated at 1 000 °C in vacuum oven of 1 kPa for 5 h. The properties of coatings were investigated. The results indicate that Fe2B appears after milling for 15 h in the powder at room temperature, a part of ternary borides (Mo2FeB2) are generated in powder sintered at 900 °C. The coatings are composed of the major phases Mo2FeB2 and α-Fe, a little of Fe2O3, FeO and some pores. The bonding strength between the substrate and the ceramic coating is 32.73 MPa, the thermal-shock times is about 43 and the wear resistance is enhanced by approximately 5.28 times compared with that of the substrate, respectively. The comprehensive properties of Mo2FeB2 cermet coatings can be improved further after vacuum heat-treatment at 1 000 °C for 5 h.
Key words: Mo2FeB2; cermet coating; reactive thermal spraying; hardness; thermal shock resistance; wear resistance