Microstructure and properties of the solid solution ceramic coating by high speed laser cladding

• The Solid solution ceramic coating was prepared by high speed laser cladding. • The additional TiB 2 underwent a sufficient substitution reaction with ZrB 2 to form (Zr x ,Ti 1-x )B 2 . • Compared to ZrB 2 , (Zr x ,Ti 1-x )B 2 exhibited significant strengthening effect on the coating. • The strengthening mechanism of (Zr x ,Ti 1-x )B 2 on the hardness and wear resistance of the coating was revealed. It is facing challenge to prepare protective ceramic coatings on the surfaces of metal parts. In this study, two types of ceramic coatings, ZrB 2 and ZrB 2 + TiB 2 , were prepared on 304 stainless steel using high speed laser cladding (HSLC) technology, and a comparative study was conducted on them. The results show that additional TiB 2 were melted sufficiently during the HSLC process and reacted with ZrB 2 to generate acicular (Zr x , Ti 1-x )B 2 structure. The existence of (Zr x , Ti 1-x )B 2 resulted in the increase of hardness from 719 HV 0.5 to 1130 HV 0.5 , and the decrease of wear rate from 8.89 × 10 -6 mm 3 / N·m to 5.0 × 10 -6 mm 3 / N·m of the coating. It can be attributed to the large lattice distortion inside (Zr x , Ti 1-x )B 2 , which improved the hardness and wear resistance compared with ZrB 2 . In addition, the friction coefficient of the coating decreased from 0.73 to 0.68 due to lubricating effect of the oxide debris generated by (Zr x , TI 1-x ) B 2 in the friction process.