Effect of Hot Extrusion and Cyclic Extrusion Compression Progress on the Microstructures and Properties of Mg-Zn-Y-Nd Alloy

2013 ◽  
Vol 745-746 ◽  
pp. 28-32 ◽  
Author(s):  
Shi Jie Zhu ◽  
Qiong Wu ◽  
Li Guo Wang ◽  
Qian Liu ◽  
Gao Chao Yue ◽  
...  

Magnesium alloys are promising candidate materials for cardiovascular stents due to their good biocompatibility and degradation property in human body. However, in vivo tests also show that improvement in mechanical property and corrosion resistance is necessary for wide application. In this study, hot extrusion and cyclic extrusion compression (CEC) were used on Mg-Zn-Y-Nd alloy, the effects of hot extrusion and CEC process on the microstructures, mechanical properties and corrosion properties of alloy were studied. The results showed that the microstructures of CEC treated Mg-Zn-Y-Nd alloy became finer and more homogenous, some nanoparticles which came from the cluster phase uniformly precipitated inside grains, alloy had good mechanical properties and corrosion resistance. The immersion test results in SBF solution at 37 for 24h showed that the alloy after CEC treatment is uniform corrosion.

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1314
Author(s):  
Ikuho Nakahata ◽  
Yusuke Tsutsumi ◽  
Equo Kobayashi

Recent studies indicate that biodegradable magnesium alloys and composites are attracting a great deal of attention in orthopedic applications. In this study, magnesium–hydroxyapatite (Mg–HAP) composites with different compositions and grain size were fabricated by a spark plasma sintering (SPS) method. Their mechanical properties and corrosion behavior in a pseudo-physiological environment were investigated by pH measurements and inductivity coupled plasma (ICP) elemental analysis after an immersion test using Hanks’ solution. The results clearly showed that the addition of HAP improved both the mechanical properties and corrosion resistance. The results also indicated that the finer grain size improved most of the properties that are needed in a material for an orthopedic implant. Furthermore, the authors reveal that there is a strong correlation between the compressive strength and the porosity. In order to achieve the same compressive strength as human bone using these fabrication conditions, it is revealed that the porosity should be lower than 1.9%.


2005 ◽  
Vol 488-489 ◽  
pp. 839-844 ◽  
Author(s):  
Young Gee Na ◽  
Dan Eliezer ◽  
Kwang Seon Shin

The development of new components with magnesium alloys for the automotive industry has increased in recent years due to their high potential as structural materials for low density and high strength/weight ratio demands. However, the limited mechanical properties of the magnesium alloys have led to search new kind of magnesium alloys for better strength and ductility. The main objective of this research is to investigate the mechanical properties and the corrosion behavior of new wrought magnesium alloys; Mg-Zn-Ag (ZQ) and Mg-Zn-Si (ZS) alloys. The ZQ6X and ZS6X samples were fabricated using hot extrusion method. Tensile tests and immersion tests were carried out on the specimens from the extruded rods, which contained different amounts of silver or silicon, in order to evaluate the mechanical properties and corrosion behavior. The microstructure was examined using optical and electron microscopy (TEM and SEM) and EDS. The results showed that the addition of silver improved the mechanical properties but decreased the corrosion resistance. The addition of silicon improved both mechanical properties and corrosion resistance. These results can be explained by the effects of alloying elements on the microstructures of the Mg-Zn alloys such as grain size and precipitates caused by the change in precipitation and recrystallization behavior.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1564 ◽  
Author(s):  
Huai Yao ◽  
Jiuba Wen ◽  
Yi Xiong ◽  
Ya Liu ◽  
Yan Lu ◽  
...  

The Mg–Zn–Zr–Gd alloys belong to a group of biometallic alloys suitable for bone substitution. While biocompatibility arises from the harmlessness of the metals, the biocorrosion behavior and its origins remain elusive. Here, aiming for the tailored biodegradability, we prepared the Mg–2.0Zn–0.5Zr–xGd (wt %) alloys with different Gd percentages (x = 0, 1, 2, 3, 4, 5), and studied their microstructures and biocorrosion behavior. Results showed that adding a moderate amount of Gd into Mg–2.0Zn–0.5Zr alloys will refine and homogenize α-Mg grains, change the morphology and distribution of (Mg, Zn)3Gd, and lead to enhancement of mechanical properties and anticorrosive performance. At the optimized content of 3.0%, the fishbone-shaped network, ellipsoidal, and rod-like (Mg, Zn)3Gd phase turns up, along with the 14H-type long period stacking ordered (14H-LPSO) structures decorated with nanoscale rod-like (Mg, Zn)3Gd phases. The 14H-LPSO structure only exists when x ≥ 3.0, and its content increases with the Gd content. The Mg–2.0Zn–0.5Zr–3.0Gd alloy possesses a better ultimate tensile strength of 204 ± 3 MPa, yield strength of 155 ± 3 MPa, and elongation of 10.6 ± 0.6%. Corrosion tests verified that the Mg–2.0Zn–0.5Zr–3.0Gd alloy possesses the best corrosion resistance and uniform corrosion mode. The microstructure impacts on the corrosion resistance were also studied.


2007 ◽  
Vol 534-536 ◽  
pp. 721-724 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Z. Brytan ◽  
Marco Actis Grande ◽  
Mario Rosso

This work presents mechanical properties and corrosion resistance of duplex stainless steels obtained through powder metallurgy starting from austenitic X2CrNiMo17-12-2 (AISI 316L), martensitic X6Cr13 (AISI 410L) powders by controlled addition of alloying elements in the proper quantity to obtain the chemical composition of the structure similar to biphasic one. In the mixes preparations the Schaffler’s diagram was taken into consideration. Prepared mixes of powders have been sintered in a vacuum furnace with argon backfilling. After sintering rapid cooling was applied using nitrogen. Produced duplex stainless steels have been studied by SEM with EDS and light optical microscopy (LOM) and X-rays analysis to determine obtained structures. Corrosion properties have been studied through electrochemical methods in 1M NaCl.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1049 ◽  
Author(s):  
Gui Lou ◽  
Shumin Xu ◽  
Xinying Teng ◽  
Zhijian Ye ◽  
Peng Jia ◽  
...  

Magnesium alloys act as ideal biomedical materials with good biocompatibility. In this paper, the extruded biomedical Mg-6Zn-0.5Nd-0.5/0.8Ca alloys were prepared and their microstructure, mechanical properties and corrosion properties were investigated. The results showed that the surfaces of Mg-6Zn-0.5Nd-0.5/0.8Ca alloys extruded at medium temperature were smooth and compact without cracks. The tensile strength and elongation of Mg-6Zn-0.5Nd-0.5/0.8Ca alloys were 222.5 MPa and 20.2%, and 287.2 MPa and 18.4%, respectively. A large number of dislocations were generated in the grains and on grain boundaries after the extrusion. The alloy was immersed in simulating body fluid (SBF) for the weightlessness corrosion, and the corrosion products were analyzed by FTIR, SEM equipped with EDS. It was found that the corrosion rate of Mg-6Zn-0.5Nd-0.5Ca and Mg-6Zn-0.5Nd-0.8Ca alloy were 0.82 and 2.98 mm/a, respectively. Furthermore, the compact layer was formed on the surface of the alloy, which can effectively hinder the permeation of Cl− and significantly improve the corrosion resistance of magnesium alloys.


Alloy Digest ◽  
1993 ◽  
Vol 42 (11) ◽  

Abstract REMANIT 4439 is a highly corrosion resistant steel with low carbon content, an addition of nitrogen to enhance both mechanical properties and corrosion resistance, and higher molybdenum than most stainless steels to resist pitting and crevice corrosion in chloride media. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-556. Producer or source: Thyssen Stahl AG.


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