Study on the Microstructure, Mechanical Properties and Corrosion Behavior of Mg-Zn-Ca Alloy Wire for Biomaterial Applica

  • PDF / 2,652,640 Bytes
  • 10 Pages / 593.972 x 792 pts Page_size
  • 90 Downloads / 212 Views

DOWNLOAD

REPORT


ÓASM International 1059-9495/$19.00

Study on the Microstructure, Mechanical Properties and Corrosion Behavior of Mg-Zn-Ca Alloy Wire for Biomaterial Application Maobo Zheng, Guangquan Xu, Debao Liu, Yue Zhao, Baoqun Ning, and Minfang Chen (Submitted August 28, 2017; in revised form February 8, 2018) Due to their excellent biocompatibility and biodegradability, magnesium alloy wires have attracted much attention for biomaterial applications including orthopedic K-wires and sutures in wound closure. In this study, Mg-3Zn-0.2Ca alloy wires were prepared by cold drawing combined with proper intermediate annealing process. Microstructures, texture, mechanical properties and corrosion behavior of Mg-3Zn0.2Ca alloy wire in a simulated body fluid were investigated. The results showed that the secondary phase and average grain size of the Mg-3Zn-0.2Ca alloy were refined in comparison with the as-extruded alloy and a strong (0002)//DD basal fiber texture system was formed after multi-pass cold drawing. After the annealing, most of the basal planes were tilted to the drawing direction (DD) by about 35°, presenting the characteristics of random texture, and the texture intensity decreased. The as-annealed wire shows good mechanical properties with the ultimate tensile strength (UTS), yield strength (YS) and elongation of 253 ± 8.5 MPa, 212 ± 11.3 MPa and 9.2 ± 0.9%, respectively. Electrochemical and hydrogen evolution measurements showed that the corrosion resistance of the Mg-3Zn-0.2Ca alloy wire was improved after the annealing. The immersion test indicated that the Mg-3Zn-0.2Ca wire exhibited uniform corrosion behavior during the initial period of immersion, but then exhibited local corrosion behavior. Keywords

cold drawing, corrosion resistance, mechanical properties, Mg-Zn-Ca alloy wire, microstructure

1. Introduction Magnesium alloys show high specific strength, high specific stiffness and good biocompatibility. Youngs elastic modulus of magnesium alloys is close to that of human bone, which can effectively reduce the stress shielding effect. In addition, degradation of magnesium alloys can be achieved by the corrosion reaction between the magnesium alloys and the body fluids in vivo and magnesium ions released by the degradation can be absorbed by many kinds of metabolic processes of the human body. Therefore, magnesium and its alloys have potential applications as degradable medical implants (Ref 13). To date, magnesium alloys have been extensively studied in biodegradable bone fracture fixation, vascular stent and porous bone tissue and other applications, further confirming that magnesium alloys show very good prospects for application as implant materials. Moreover, some researchers have explored the use of magnesium alloys in peripheral nerve repair, sutures and anastomotic nails (Ref 4-6). These medical instruments are usually fabricated using magnesium alloy wire. Therefore, the

Maobo Zheng, Guangquan Xu, Debao Liu, and Yue Zhao, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin

Data Loading...