Cailiao Baohu (Jul 2023)

Influences of La(NO<sub>3</sub>)<sub>3</sub> Doping on the Microstructure and Wear Resistance of Micro-Arc Oxidation / Hydrothermal Coating Developed on TC4 Alloy

  • ZHANG Yunlong, NIU Chuhan, DONG Xinyan, ZHANG Yumin, LI Qirong, LI Chenghai, ZHANG Ruixia, ZHANG Weiyi

DOI
https://doi.org/10.16577/j.issn.1001-1560.2023.0155
Journal volume & issue
Vol. 56, no. 7
pp. 10 – 16

Abstract

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 As a biomedical material，TC4 titanium alloy is widely used in the field of bone tissue repair in clinical practice，with annual consumption of about one million pieces in China.However，the properties of TC4 titanium alloy as low wear resistance and poor biological activity seriously restricted its expansion in engineering application.Therefore，a micro-arc oxidation/hydrothermal coating on surface of TC4 was fabricated by utilizing the micro-arc oxidation/hydrothermal synthetic composite technology，and the effects of La(NO3)3 doping amount in the hydrothermal synthesis solution on the phase composition，micro morphology，microhardness，wear resistance and other parameters of the micro-arc oxidation/hydrothermal coating on TC4 titanium alloy were surveyed.Moreover，the micro-arc oxidation/hydrothermal coating on TC4 titanium alloy was characterized by XRD，SEM，microhardness tester and friction and wear testing machine.Results showed that the micro-arc oxidation/hydrothermal coating on TC4 titanium alloy was mainly composed of anatase TiO2 and hydroxyapatite.After hydrothermal treatment，La3+ in the synthetic solution entered the composite coating and participated in the coating reaction.With the increase of La(NO3)3 doping amount，the content of hydroxyapatite phase in the composite coating increased first and then decreased.When the doping amount of La(NO3)3 exceeded 24 mmol/L，the coating surface became smoother.In addition，the microhardness of micro-arc oxidation/hydrothermal composite coating on TC4 titanium alloy decreased first and then increased，and the friction coefficient increased first and then decreased.As the doping amount of La(NO3)3 reached 24 mmol/L，microhardness of the composite coating on TC4 titanium alloy acquired the minimum value，and it was about (271.8±3.1)HV9.8 N，the friction coefficient of the composite coating obtained the maximum value，and it was about 0.8～0.9.

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