Microstructure and wear resistance of nano titanium dioxide strengthening hardfacing material

• Published in: Vacuum 2019-04, Vol.162, p.175-182
• Main Authors: Chen, Cui-xin, Zuo, Yu-qiang, Liu, Bao-xi, Xue, Hai-tao, Ma, Bin, Li, Xu-chen
• Format: Article
• Language: English
• Subjects: Carbides; Hardfacing materials; Hardness; Nano-TiO2; Wear resistance
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2019.01.045

The nanometer TiO2 particles (nano-TiO2) was added into the hardfacing materials to study grain refinement, the effect on phase transformation, and the amount, morphology and distribution of precipitation. Moreover, the relationship between nano-TiO2 addition and hardness, wear resistance of the hardfacing material were also investigated in this article. The nano-TiO2 transforms to Ti3O5 firstly at around 1660 °C and then transforms to Ti2O3 and MnTi2O4 at around 600 °C and 550 °C, respectively. The nano-TiO2 has an obvious effect on grain refinement and the grain size is decreased gradually with the increase of nano-TiO2. Nano-TiO2 has no significant influence on the size of MC carbides but change the carbides morphology. Moreover, the content of MC particles reaches to the highest value of 6.8% when the addition of nano-TiO2 is 0.6%. Meanwhile, due to grain refinement, the carbides distribute more homogeneously with the addition of nano-TiO2. However, the particles present network distribution along the grain boundary when nano-TiO2 is 0.8 wt%. Moreover, the hardness of hardfacing alloys was the highest value of 56.4HRC when the content of nano-TiO2 is 0.6 wt%. In addition, the wear resistance of the hard facing layer can be improved for the uniform of the microstructure and the increase of carbides after the addition of nano-TiO2. •Nano-TiO2 particles were coated on the pure Fe powders to avoid aggregation.•Nano-TiO2 has an obvious effect on the morphology of carbides.•Nano-TiO2 has a good grain refinement on the hardfacing material.•The hardness is highest with addition of 0.6% nano-TiO2.•The friction coefficient is lowest 0.56 with addition of 0.6% nano-TiO2.