3D TiO2 foam-supported Ni–B-La films for superior anti-corrosive and tribo-mechanical performances

Abstract

Herein the self-lubricating Ni-B-La films were deposited onto porous surfaces of Ti substrate to modify its surface defects like low hardness, poor wear resistance, etc. The anodized titanium oxides (ATO) surfaces within 3D foam-like nanoporous textures were created for pinning growth by low-temperature electroless Ni-B nanocrystals to increase the interfacial strength. Specifically, the impact of LaCl₃ addition and aging temperatures on structural and tribo-mechanical characteristics of Ni-B-La films were assessed. The results validated that, instead of the cauliflower-like cellular, the inclusion of La³⁺ in plating bath was favorable for a flat surface within microcrystal textures. Through aged at 350 °C, it depicted the highest microhardness of 1163.6HV_0.1 and the lowest coefficients of friction (COF) value of ∼0.12 for Ni-B-La (3 g/L LaCl₃) samples. Additionally, the wear rate of Ni-B-La films was lower than 1.76 × 10⁻³ mm³·N⁻¹·m⁻¹, reducing by 667.1 % and 133.0 % than those of Ti substrate and Ni-B alloys. Both the precipitations of hard Ni_xB particles and La-rich oxides resulted in the self-lubricating surfaces. Our work offers exceptional prospects for La-doped Ni-B films towards porous surfaces, allowing to satisfy the surface functional of Ti-based engineering applications under dry friction conditions.