Acta Metallurgica Sinica (English Letters) ›› 2020, Vol. 33 ›› Issue (1): 103-114.DOI: 10.1007/s40195-019-00956-6

• Original Paper • Previous Articles     Next Articles

Preparation of Biodegradable Mg/β-TCP Biofunctional Gradient Materials by Friction Stir Processing and Pulse Reverse Current Electrodeposition

Yabo Zhang1, Huiling Yang1, Shaoqian Lei1, Shijie Zhu1,2(), Jianfeng Wang1,2, Yufeng Sun1,2, Shaokang Guan1,2()   

  1. 1 School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
    2 Henan Key Laboratory of Advanced Magnesium Alloys, Zhengzhou 450002, China
  • Received:2019-04-10 Revised:2019-07-18 Online:2020-01-10 Published:2020-02-20
  • Contact: Zhu Shijie,Guan Shaokang

Abstract:

Mg alloys, as a new generation of biodegradable bone implant materials, are facing two tremendous challenges of enhancing strength and reducing degradation rate in physiological environment to meet clinical needs. In this study, tricalcium phosphate (β-TCP) particles were dispersed in Mg-2Zn-0.46Y-0.5Nd alloy by friction stir processing (FSP) to produce Mg-based functional gradient materials (Mg/β-TCP FGM). On the surface of Mg/β-TCP FGM, the hydroxyapatite (HA) coating was prepared by electrodeposition. The effects of FSP and electrochemical parameter on the microstructure, microhardness, bonding strength and corrosion performance of the Mg/β-TCP FGM were investigated. After four passes of FSP, a uniform and fine-grained structure was formed in Mg/β-TCP and the microhardness increased from 47.9 to 76.3 HV. Compared to the samples without β-TCP, the bonding strength of the Mg/β-TCP FGM increased from 23.1?±?0.462 to 26.3?±?0.526 MPa and the addition of degradable β-TCP contributed to the in situ growth of HA coating. The thickness of HA coating could be dominated by controlling the parameters of electrodeposition. According to the results of immersion tests and electrochemical tests in simulated body fluid, it indicated that the degradation rate of the Mg/β-TCP FGM could be adjusted.

Key words: Biodegradable magnesium alloy, Biofunctional gradient materials, Friction stir processing, Tricalcium phosphate (β-TCP);, Electrodeposition