Compressive and Corrosion Properties of Lotus-Type Porous Mg-Mn Alloys Fabricated by Unidirectional Solidification
- PDF / 5,037,627 Bytes
- 10 Pages / 593.972 x 792 pts Page_size
- 22 Downloads / 232 Views
INTRODUCTION
MAGNESIUM and magnesium alloys, as lightweight alloys, show great potential for modern applications, such as the aerospace, automotive, communication, electronics, and other fields.[1–4] Magnesium-based biomaterials have been considered potential biodegradable materials. Biodegradable implant materials in the human body can be dissolved, absorbed, consumed or excreted gradually, so there is no need for secondary surgery to remove implants after surgery regions have healed. Magnesium and its alloys have an appropriate strength for human function. Magnesium ions that are released from degradable implants can stabilize DNA/RNA structures, which is essential for the human body.[5–8] Porous materials as implants facilitate bone ingrowth and may allow for implant stability by biological fixation and nutrient transport for
CANXU ZHOU is with the Department of Materials Engineering, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China. YUAN LIU, HUAWEI ZHANG, XIANG CHEN, and YANXIANG LI are with the Department of Materials Engineering, School of Materials Science and Engineering, Tsinghua University, and also with the Key Laboratory for Advanced Materials Processing Technology, Beijing, 100084, China. Contact e-mail: [email protected] Manuscript submitted October 23, 2019.
METALLURGICAL AND MATERIALS TRANSACTIONS A
faster healing, which makes them promising materials for orthopedic applications.[9–12] These materials can provide a cell ingrowth microenvironment and a favorable therapeutic effect.[13] These advantages make Mg-based porous materials promising candidates for bone-tissue engineering scaffolds. Therefore, research can aid in the development of biodegradable implant materials. For load-bearing orthopedic applications, magnesium scaffolds require a high strength to support the loads and to maintain a low degradation rate. However, because of the exposed surface area that contacts the corrosive medium, medical applications of porous Mg scaffolds are limited because of their rapid corrosion, which decreases the scaffold mechanical strength significantly. Stress concentration that appears around the pore area of these porous materials can deteriorate the mechanical properties.[14] Various methods have been proposed to improve the properties of porous magnesium. Kang et al. found that coating biomimetic porous magnesium with a HA/(PEI-SiO2) hybrid layer can improve the corrosion resistance and biocompatibility,[15] but cracks often form on the coating layer, which may allow body fluids to penetrate the cracks and reach the Mg structure. Jia et al. prepared open porous magnesium scaffolds using NaCl templates, and found that S-scaffolds with spherical pores may be more suitable than I-scaffolds with irregular pores for clinical applications because of their better interconnectivity
and structural integrity.[12] However, the remaining salt inclusions inside closed pores can decrease the corrosion resistance. A new type of porous metal with cylindrical pores that align in
Data Loading...
