Microstructure and wear resistance of laser clad TiC reinforced FeAl intermetallic matrix composite coatings

TiC reinforced FeAl intermetallic matrix composite coatings were fabricated on stainless steel substrates by laser cladding. Microstructure of the coatings was observed by optical microscopy, scanning electron microscopy and transmission electron microscopy. The dry sliding wear resistance of the coatings was investigated as a function of applied load, and the wear mechanisms were discussed based on worn surfaces and wear debris examinations. Results showed that the coatings can be obtained with the features of good metallurgical bonding to the substrates, and there are two phases in the composite coating: TiC and FeAl intermetallic. The growth morphology of TiC phase is mainly in radial-branching dendritic. The wear rate of TiC reinforced FeAl composite coating increases with increasing applied load. Investigation of worn surfaces and wear debris by scanning electron microscopy indicated that there is a transition of the wear mechanism from abrasive wear to adhesive wear with increasing applied load. Furthermore, with the increase of volume fraction of TiC, wear resistance of the coatings is improved.