Abstract
Microstructure and corrosion behavior of the solution-treated Mg-1.8Zn-1.74Gd-0.5Y-0.4Zr (wt%) alloy were studied. The results of microstructure indicated that the second phases of as-cast alloy was mainly comprised of Mg12Zn(Gd,Y) phase, Mg3Zn3(Gd,Y)2 phase and (Mg,Zn)3(Gd,Y) phase. After solution treatment process, the second phase gradually dissolved into the matrix, and the grain size increased. The effect of microgalvanic corrosion between α-Mg matrix and second phase was also improved. At the range of 470~510 °C solution treatment temperature, the corrosion resistance of the samples increases at first and then decreases slightly at 510 °C. All the solution-treated Mg-Zn-Gd-Y-Zr samples exhibit better corrosion resistance in comparison with as-cast sample. The existence form of the remaining phase affects the morphology of the corroded surface that relatively complete dissolution with homogeneous microstructure makes the sample more effective to obtain uniform corrosion form. The optimum temperature for solution treatment is 490 °C, which shows a much better corrosion resistance and uniform corrosion form after soaking for a long time.
Highlights
Compared with traditional materials, magnesium (Mg) alloys, as biomedical materials, have a good application prospect due to the low elastic modulus, light quality, biodegradability and favorable biocompatibility [1,2,3]
Mg alloys are vulnerable to microgalvanic corrosion
To overcome the rapid corrosion rate in the service period, a lot of studies have been done to improve the performance of corrosion, such as micro-alloying [6,7,8], surface modification and composites [9,10]
Summary
Magnesium (Mg) alloys, as biomedical materials, have a good application prospect due to the low elastic modulus (close to human bone), light quality, biodegradability and favorable biocompatibility [1,2,3]. The addition of Gd element can markedly ameliorate both the corrosion resistance and mechanical properties [7]. Jafari et al [8] showed that Y in the matrix of as-cast Mg-5Zn can effectively slow the propagation of corrosion. Zhang et al [24] studied the effects of solution treatment at different temperatures. By studying the holding time of solution treatment, Jafari et al [19] showed that the corrosion rate in solution treated Mg-5Zn-1.5Y was decreased by a more homogenous distribution of Y with the prolong of time. The disadvantage is that grain coarsening after long-time solution treatment reduces mechanical properties with the extension of holding time. The suitable solution treatment temperature of the alloy is investigated and the solution treatment effect on the microstructure and corrosion resistance is conducted to discuss
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
