In this study,the microstructure and tensile properties of selective laser melted AlSilOMg at elevated temperature were investigated with focus on the interfacial region.In-situ SEM and in-situ EBSD analysis were prop...In this study,the microstructure and tensile properties of selective laser melted AlSilOMg at elevated temperature were investigated with focus on the interfacial region.In-situ SEM and in-situ EBSD analysis were proposed to characterize the microstructural evolution with temperature.The as-fabricated AlSilOMg sample presents high tensile strength with the ultimate tensile strength(UTS)of~450 MPa and yield strength(YS)of~300 MPa,which results from the mixed strengthening mechanism among grain boundary,solid solution,dislocation and Orowan looping mechanism.When holding at the temperature below 200℃for 30 min,the micro structure presents little change,and only a slight decrement of yield strength appears due to the relief of the residual stress.However,when the holding temperature further increases to 300℃and 400℃,the coarsening and precipitation of Si particles inα-Al matrix occur obviously,which leads to an obvious decrease of solid solution strength.At the same time,matrix softening and the weakness of dislocation strengthening also play important roles.When the holding temperature reaches to 400℃,the yield strength decreases significantly to about 25 MPa which is very similar to the as-cast Al alloy.This might be concluded that the YS is dominated by the matrix materials.Because the softening mechanism counteracts work hardening,the extremely high elongation occurs.展开更多
In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the E...In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the EHEA exhibits a superb corrosion resistance in 1 M NaCl in terms of a very low corrosion current density and an ultra-high transpassviation potential,which outperforms a variety of other HEAs and conventional metals and alloys.At the fundamental level,the microstructure refinement results in a rapid formation of a thick and compact passive film with less Cl-adsorption on the EHEA,which results in significant enhancement in its corrosion resistance.The outcome of our research provides important insights into the design of corrosion resistant chemically complex alloys.展开更多
基金supported financially by the National Key Research and Development Programme of China(Nos.2016YFB1100602 and 2016YFB1100100)。
文摘In this study,the microstructure and tensile properties of selective laser melted AlSilOMg at elevated temperature were investigated with focus on the interfacial region.In-situ SEM and in-situ EBSD analysis were proposed to characterize the microstructural evolution with temperature.The as-fabricated AlSilOMg sample presents high tensile strength with the ultimate tensile strength(UTS)of~450 MPa and yield strength(YS)of~300 MPa,which results from the mixed strengthening mechanism among grain boundary,solid solution,dislocation and Orowan looping mechanism.When holding at the temperature below 200℃for 30 min,the micro structure presents little change,and only a slight decrement of yield strength appears due to the relief of the residual stress.However,when the holding temperature further increases to 300℃and 400℃,the coarsening and precipitation of Si particles inα-Al matrix occur obviously,which leads to an obvious decrease of solid solution strength.At the same time,matrix softening and the weakness of dislocation strengthening also play important roles.When the holding temperature reaches to 400℃,the yield strength decreases significantly to about 25 MPa which is very similar to the as-cast Al alloy.This might be concluded that the YS is dominated by the matrix materials.Because the softening mechanism counteracts work hardening,the extremely high elongation occurs.
基金supported by the Research Grant Council(RGC),Hong Kong Government,through the General Research Fund(GRF)with the grant number City U11213118 and City U11209317。
文摘In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EHEA)can be tuned by controlling the size of its eutectic structure.Through microstructure refinement,the EHEA exhibits a superb corrosion resistance in 1 M NaCl in terms of a very low corrosion current density and an ultra-high transpassviation potential,which outperforms a variety of other HEAs and conventional metals and alloys.At the fundamental level,the microstructure refinement results in a rapid formation of a thick and compact passive film with less Cl-adsorption on the EHEA,which results in significant enhancement in its corrosion resistance.The outcome of our research provides important insights into the design of corrosion resistant chemically complex alloys.
