In this work, the corrosion behavior of the ascast and extrusion and aging treatment Mg–2Zn–0.2Mn alloy in simulated body fluid(SBF) were studied. The wear behavior of Mg–2Zn–0.2Mn alloy was investigated using pin...In this work, the corrosion behavior of the ascast and extrusion and aging treatment Mg–2Zn–0.2Mn alloy in simulated body fluid(SBF) were studied. The wear behavior of Mg–2Zn–0.2Mn alloy was investigated using pin-on-disk technique and stainless steel as counterbody under a constant sliding velocity at different loads ranging from 2 to 5 N with deionized water and SBF as lubrication.The results showed that the extrusion and aging treatment Mg–2Zn–0.2Mn alloy exhibited better corrosion resistance compared with the as-cast alloy due to finer average grain size, more homogeneous phase distribution, and decrease in porosity. The friction coefficient of fractional pair under SBF and deionized water lubrication were obviously lower than that of dry sliding condition. However, the wear rate of Mg–2Zn–0.2Mn alloy under SBF lubrication was higher than that of dry sliding and deionized water lubrication due to the corrosiveness of SBF accelerated the wear of the magnesium alloy. The magnesium alloy exhibited different wear mechanisms with the variety of loads and lubrication conditions.展开更多
An innovative constitutive model for the rheological behavior of the polymer/carbon nanotubes composites is proposed in this paper. Based on experimental investigations, this consistent law gives the evolution of the ...An innovative constitutive model for the rheological behavior of the polymer/carbon nanotubes composites is proposed in this paper. Based on experimental investigations, this consistent law gives the evolution of the composite shear viscosity versus the shear rate, over a large range, and the temperature with various carbon nanotubes mass fractions. Hence, this consistent could be implemented in a finite element code in order to lead many polymer/carbon nanotubes manufacturing process like injection molding or hot embossing.展开更多
A new cast Mg-2Gd-2Nd-2Y-1Ho-1Er-0.5Zn-0.4Zr （wt%） alloy was prepared by direct-chill semicontinuous casting technology. The microstructure, mechanical properties and thermal conductivity of the alloy in as-cast, so...A new cast Mg-2Gd-2Nd-2Y-1Ho-1Er-0.5Zn-0.4Zr （wt%） alloy was prepared by direct-chill semicontinuous casting technology. The microstructure, mechanical properties and thermal conductivity of the alloy in as-cast, solid-solution treated and especially peak-aged conditions were investigated. The as-cast alloy mainly consists of α-Mg matrix, （Mg, Zn）3 RE phase and basal plane stacking faults. After proper solid-solution treatment, the microstructure becomes almost Mg-based single phase solid solution except just very few RE-riched particles. The as-cast and solid-solution treated alloys exhibit moderate tensile properties and thermal conductivity. It is noteworthy that the Mg alloy with 8 wt% multiple RE exhibits remarkable age-hardening response （AHV=35.7）, which demonstrates that the multiple RE （RE = Gd, Nd, Y, Ho, Er） alloying instead of single Gd can effectively improve the age-hardening response. The peak-aged alloy has a relatively good combination of high strength/hardness （UTS （ultimate tensile strength） 〉 300 MPa; TYS （tensile yield strength）〉210 MPa; 115.3 HV）, proper ductility （ε≈ 6%） and moderate thermal conductivity （52.5 W/（m K））. The relative mechanisms mainly involving aging precipitation of β″ and β＂ phases were discussed. The results provide a basis for development of high performance cast Mg alloys.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51271131 and 51071108)
文摘In this work, the corrosion behavior of the ascast and extrusion and aging treatment Mg–2Zn–0.2Mn alloy in simulated body fluid(SBF) were studied. The wear behavior of Mg–2Zn–0.2Mn alloy was investigated using pin-on-disk technique and stainless steel as counterbody under a constant sliding velocity at different loads ranging from 2 to 5 N with deionized water and SBF as lubrication.The results showed that the extrusion and aging treatment Mg–2Zn–0.2Mn alloy exhibited better corrosion resistance compared with the as-cast alloy due to finer average grain size, more homogeneous phase distribution, and decrease in porosity. The friction coefficient of fractional pair under SBF and deionized water lubrication were obviously lower than that of dry sliding condition. However, the wear rate of Mg–2Zn–0.2Mn alloy under SBF lubrication was higher than that of dry sliding and deionized water lubrication due to the corrosiveness of SBF accelerated the wear of the magnesium alloy. The magnesium alloy exhibited different wear mechanisms with the variety of loads and lubrication conditions.
文摘An innovative constitutive model for the rheological behavior of the polymer/carbon nanotubes composites is proposed in this paper. Based on experimental investigations, this consistent law gives the evolution of the composite shear viscosity versus the shear rate, over a large range, and the temperature with various carbon nanotubes mass fractions. Hence, this consistent could be implemented in a finite element code in order to lead many polymer/carbon nanotubes manufacturing process like injection molding or hot embossing.
基金supported by the Natural Science Foundation of Heilongjiang Province of China (No. E2017030)National Natural Science Foundation of China (No. 51301048)+2 种基金Foundation of State Key Laboratory of Rare Earth Resources Utilization (No. RERU2016025)Central University Foundation of Harbin Engineering University (No. GK2100260207)the Natural Science Foundation of Jiamusi University of China (No. JMSURCGG2016006)
文摘A new cast Mg-2Gd-2Nd-2Y-1Ho-1Er-0.5Zn-0.4Zr （wt%） alloy was prepared by direct-chill semicontinuous casting technology. The microstructure, mechanical properties and thermal conductivity of the alloy in as-cast, solid-solution treated and especially peak-aged conditions were investigated. The as-cast alloy mainly consists of α-Mg matrix, （Mg, Zn）3 RE phase and basal plane stacking faults. After proper solid-solution treatment, the microstructure becomes almost Mg-based single phase solid solution except just very few RE-riched particles. The as-cast and solid-solution treated alloys exhibit moderate tensile properties and thermal conductivity. It is noteworthy that the Mg alloy with 8 wt% multiple RE exhibits remarkable age-hardening response （AHV=35.7）, which demonstrates that the multiple RE （RE = Gd, Nd, Y, Ho, Er） alloying instead of single Gd can effectively improve the age-hardening response. The peak-aged alloy has a relatively good combination of high strength/hardness （UTS （ultimate tensile strength） 〉 300 MPa; TYS （tensile yield strength）〉210 MPa; 115.3 HV）, proper ductility （ε≈ 6%） and moderate thermal conductivity （52.5 W/（m K））. The relative mechanisms mainly involving aging precipitation of β″ and β＂ phases were discussed. The results provide a basis for development of high performance cast Mg alloys.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
