Improved wear properties of NiTi nanocomposite coating with tailored spatial microstructures by extra adding CeO2 nanoparticles

In the present work, CeO 2 nanoparticles were extra added into Ni Ti nanocomposite coating to optimize the spatial microstructures and wear properties. Before adding CeO 2 nanoparticles into Ni Ti nanocomposite coating, Ti microparticles distributed in forms of cluster in Ni deposits, leading to the spatial inhomogeneity of microstructures like local large grains and residual [200] fiber textures. Correspondingly, the hardness in small-grain regions was up to ~4456 ± 46 MPa, while the hardness in large-grain areas dropped to values as low as ~3493 ± 40 MPa. Besides that, inside pores and jagged surface were observable, confining the wear resistance capacity. The average hardness was ~3814 ± 279 MPa. After extra adding CeO 2 nanoparticles into Ni Ti nanocomposite coating, Ti microparticles homogeneously scattered throughout the whole nanocomposite coating, leading to the spatial homogeneity of microstructures and properties. Grain size steadily kept at ~40 nm and the hardness stabilized at ~4326 ± 150 MPa. Inside pores vanished, the surface became smooth, and residual [2 0 0] texture was fractured. Benefiting from the modified spatial microstructures and improved hardness, enhanced wear resistance was achieved.