Microstructure and Wear Resistance of TiB2-Fe Matrix Coating Deposited by Atmosphere Plasma Spray

TiB₂-316L matrix composite powders containing 40, 50, 60,75, 85mass% TiB₂ were prepared by ball milling, spray-drying and sintering processes and the corresponding coatings were deposited by atmosphere plasma spraying as well as 316L stainless steel coating. The influence of TiB₂ content of feedstock powders on microstructure and wear resistance of as-sprayed coatings were investigated. SEM, XRD and microhardness tester were employed to character the coatings. The sliding wear resistance of the coatings was evaluated by block-on-ring tests. Results show that TiB₂ particles which remain undeformed shape in the coatings distribute in metal matrix; wear resistance of the coatings increases with the TiB₂ content when it is less than 75%, due to TiB₂ dispersedly reinforcing metal matrix; while high level content of TiB₂ weaken wear resistance of the coatings resulting from the TiB₂ particles agglomerating.