The Metal-ceramic Coating Containing TiB₂ Of Plasma Transferred Arc Surfacing

The TiB₂ whisker is synthesized in-situ during the reaction of the alloy powders employing the plasma arc powder surfacing. The TiB₂ whiskers uniformly disperse in the metal matrix, which originate from the alloy powders employed in the plasma arc powder surfacing. The ceramic coatings mainly consist of the TiB₂ whisker and the chemical compound of Fe,C and B. And the coatings and the matrix are metallurgical bonded. Through controling the input of line energy to command the dilution rate,the content of Ti,B in the molten pool and the quantity of TiB₂ during synthesized in-situ.It is indicated that following the increasing of line energy input, the TiB₂ whiskers become large and the ratio of length and width decreases in the coatings.The distribution of TiB₂ at vertical orientation also exist difference. The ceramic coatings have rational gradient structure. The quantities of boron and the hardness of the coatings rise increasingly from the fusion line to the surface of the coatings.Because of the high content of carbon result in the high content of garphite phase in the coatings,this would be a great impact to the performance of the coatings.In this experiment we use B₂O₃ and FeB substitute B4C in order to decrease the content of carbon,the result indicated that use FeB substitute B4C is feasible.