Microstructure and bio-corrosion behaviour of Mg-5Zn-0.5Ca -xSr alloys as potential biodegradable implant materials. (6th April 2018)

• Record Type: Journal Article
• Authors: Yan, Li; Zhou, Jiaxing; Sun, Zhenzhou; Yang, Meng; Ma, Liqun
• Is Part Of: Materials research express. Volume 5:Number 4(2018)
• Publication Date: 2018-04-06
• Subjects: magnesium alloy -- Sr addition -- microstructure -- corrosion resistance -- corrosion products -- grain boundary -- corrosion morphology; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aab878
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Magnesium alloys are widely studied as biomedical implants owing to their biodegradability. In this work, novel Mg-5Zn-0.5Ca-xSr (x = 0, 0.14, 0.36, 0.50, 0.70 wt%) alloys were prepared as biomedical materials. The influence of strontium (Sr) addition on the microstructure, corrosion properties and corrosion morphology of the as-cast Mg-5Zn-0.5Ca-xSr alloys is investigated by a variety of techniques such as scanning electron microscopy, x-ray diffraction, and electrochemical measurements. The Sr-free alloy is composed of three phases, namely, α -Mg, CaMg2 and Ca2 Mg6 Zn3, while the alloys with the Sr addition consist of α -Mg, CaMg2 and Ca2 Mg6 Zn3 and Mg17 Sr2 . Corrosion experiments in Hank's solution show that the addition of a small amount of Sr can improve the corrosion resistance of the Mg-5Zn-0.5Ca alloy. The corrosion products include Mg(OH)2, Zn(OH)2, Ca(OH)2, and HA (Ca5 (PO4 )3 (OH)). Mg-5Zn-0.5Ca-0.36Sr alloy has the minimum weight loss rate (0.68 mm/a), minimal hydrogen evolution (0.08 ml/cm 2 /d) and minimum corrosion current density (7.4 μ A/cm 2 ), indicating that this alloy shows the best corrosion resistance.