Borosiliciding of Fe-Ni alloys and evaluation of their resistance to abrasive wear

X-ray diffraction analysis, Mossbauer measurements and metallographic observations were performed on borosilicide coatings grown at 850C on Armco iron and the Fe64Ni36 binary alloy using a KBF4-activated powder mixture of B4C and Si3N4. The phase composition of the coatings was determined, a result allowing to show that the thermochemical treatment gives rise to iron boriding and iron siliciding reactions of different strength, depending on the treated material. The presence of Ni in the base metal allows iron-free nickel silicides to form as important components of the coating. The resistance of borosilicide coatings to abrasive wear is evaluated and discussed.