Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility,...Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility, and bioactivity, the engagement of Mg alloys is key for a number of biological functionalities in the human body. The unique biodegradation nature of Mg alloy implants implies that it may not require a secondary removal procedure when the expected supporting tasks accomplish, as they may simply and safely "disappear" over time. Nonetheless, the demonstrated drawback of potentially rapid degradation, is an issue that must be addressed appropriately for Mg implants and is consequently given unique attention in this review article. Herein, the critical criteria and the state-of-the-art strategies for controlling the degradation process of Mg alloys are reported. Furthermore, future developments of biodegradable Mg and its alloys systems with satisfactory specifications for clinical trials and deployment,are discussed. This review aims to provide information to materials scientists and clinical practitioners in the context of developing practical biodegradable Mg alloys.展开更多
Recently, more and more attention is paid on applications of molten chlorides in concentrated solar power （CSP） plants as high-temperature thermal energy storage （TES） and heat transfer fluid （HTF） materials due...Recently, more and more attention is paid on applications of molten chlorides in concentrated solar power （CSP） plants as high-temperature thermal energy storage （TES） and heat transfer fluid （HTF） materials due to their high thermal stability limits and low prices, compared to the commercial TES/HTF materials in CSP- nitrate salt mixtures. A higher TES/HTF operating temperature leads to higher efficiency of thermal to electrical energy conversion of the power block in CSP, however causes additional challenges, particularly increased corrosiveness of metallic alloys used as contain- ers and structural materials. Thus, it is essential to study corrosion behaviors and mechanisms of metallic alloys in molten chlorides at operating temperatures （500-800℃） for realizing the commercial application of molten chlorides in CSE The results of studies on hot corrosion of metallic alloys in molten chlorides are reviewed to understand their corrosion behaviors and mechanisms under various conditions （e.g., temperature, atmosphere）. Emphasis has also been given on salt purification to reduce corrosive impurities in molten chlorides and development of electrochemical techniques to in-situ monitor corrosive impurities in molten chlorides, in order to efficiently control corrosion rates of metallic alloys in molten chlorides to meet the requirements of industrial applications.展开更多
Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl sol...Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl solution. The EIS results obtained at the open-circuit corrosion potential have been interpreted using a model involving the impedance of particle to particle contact to account for the increasing resistance between zinc particles with immersion period, in addition to the impedance due to the zinc surface oxide layer and the electrical resistivity of the binder. Galvanic current and dc potential measurements allowed us to conclude that the cathodic protection effect of the paint takes some time to be achieved. The loss of cathodic protection is due to a double effect: the decrease of the Zn/Fe area ratio due to Zn corrosion and the loss of electric contact between Zn to Zn particles. Even when the cathodic protection effect by Zn dust become weak, the substrate steel is still protected against corrosion due to the barrier nature of the ZRP film reinforced by Zn.展开更多
基金financial support through VC Fellowships and Enabling Capability Platform for Advanced Manufacturing and FabricationFinancial support from the Australian Research Council through DECRA (DE130100090) and Linkage Schemes (LP150100343) is also gratefully acknowledged+2 种基金 support by the National Natural Science Foundation of China (51571134)Shandong University of Science and Technology Research Fund (2014TDJH104)supported by the Natural Science Foundation of the Higher Education Institute of Jiangsu Province (17KJB430003)
文摘Magnesium(Mg) alloys possess comparable physical and mechanical properties to bone, making them an outstanding candidate of implant materials for bone fracture treatment. In addition to the excellent biocompatibility, and bioactivity, the engagement of Mg alloys is key for a number of biological functionalities in the human body. The unique biodegradation nature of Mg alloy implants implies that it may not require a secondary removal procedure when the expected supporting tasks accomplish, as they may simply and safely "disappear" over time. Nonetheless, the demonstrated drawback of potentially rapid degradation, is an issue that must be addressed appropriately for Mg implants and is consequently given unique attention in this review article. Herein, the critical criteria and the state-of-the-art strategies for controlling the degradation process of Mg alloys are reported. Furthermore, future developments of biodegradable Mg and its alloys systems with satisfactory specifications for clinical trials and deployment,are discussed. This review aims to provide information to materials scientists and clinical practitioners in the context of developing practical biodegradable Mg alloys.
文摘Recently, more and more attention is paid on applications of molten chlorides in concentrated solar power （CSP） plants as high-temperature thermal energy storage （TES） and heat transfer fluid （HTF） materials due to their high thermal stability limits and low prices, compared to the commercial TES/HTF materials in CSP- nitrate salt mixtures. A higher TES/HTF operating temperature leads to higher efficiency of thermal to electrical energy conversion of the power block in CSP, however causes additional challenges, particularly increased corrosiveness of metallic alloys used as contain- ers and structural materials. Thus, it is essential to study corrosion behaviors and mechanisms of metallic alloys in molten chlorides at operating temperatures （500-800℃） for realizing the commercial application of molten chlorides in CSE The results of studies on hot corrosion of metallic alloys in molten chlorides are reviewed to understand their corrosion behaviors and mechanisms under various conditions （e.g., temperature, atmosphere）. Emphasis has also been given on salt purification to reduce corrosive impurities in molten chlorides and development of electrochemical techniques to in-situ monitor corrosive impurities in molten chlorides, in order to efficiently control corrosion rates of metallic alloys in molten chlorides to meet the requirements of industrial applications.
文摘Electrochemical impedance spectroscopy (EIS) in the l00 kHz-10 mHz frequency range was employed as the main electrochemical technique to study the corrosion protection behaviour of zinc rich epoxy paint in 3% NaCl solution. The EIS results obtained at the open-circuit corrosion potential have been interpreted using a model involving the impedance of particle to particle contact to account for the increasing resistance between zinc particles with immersion period, in addition to the impedance due to the zinc surface oxide layer and the electrical resistivity of the binder. Galvanic current and dc potential measurements allowed us to conclude that the cathodic protection effect of the paint takes some time to be achieved. The loss of cathodic protection is due to a double effect: the decrease of the Zn/Fe area ratio due to Zn corrosion and the loss of electric contact between Zn to Zn particles. Even when the cathodic protection effect by Zn dust become weak, the substrate steel is still protected against corrosion due to the barrier nature of the ZRP film reinforced by Zn.
