This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg alloy.Two kinds of nano-particles(ZrO_(2)and TiO_(2))wer...This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg alloy.Two kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/Na2SiO3electrolyte.The characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic polarization.It was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and dispersed.The nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in grains.It effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge pores.The MAO coating on Zr-FSP sample had good wettability and corrosion resistance.However,TiO_(2)particles were hardly detected in the coating on TiFSP sample.展开更多
The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method...The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method.The substitutional solution models were used to describe liquid and solid solution phases,the sub-lattice models were used to describe ternary compounds,and then the thermodynamic parameters were obtained by the least square method combined with literature experiment results.The acquired thermodynamic parameters were used to calculate the isothermal sections of the ZrO_(2)−CaO−TiO_(2)system at 1473 and 1673 K.There existed a good agreement between experimental and predicted phase relationships,the experimental points which were inconsistent with calculated results may be attributed to experimental errors and the sluggish kinetics of cations for ZrO_(2)-based materials.In order to further verify the validity of the database,the thermodynamic parameters were also used to simulate the thermodynamic properties(specific heat capacity,enthalpy,and entropy)of CaZrTi_(2)O_(7) within 5%errors.Good consistency demonstrated that the present thermodynamic database was self-consistent and credible.展开更多
通过溶剂热法制备了球状C-TiO_(2)催化剂以及BiOCl/C-TiO_(2)复合光催化材料。与纯TiO_(2)相比,球状C-TiO_(2)和BiOCl/C-TiO_(2)的禁带宽度显著降低。以亚甲基蓝为降解目标,当染料质量浓度为25 mg/L、pH为7时,0.1 g BiOCl/CTiO_(2)对其...通过溶剂热法制备了球状C-TiO_(2)催化剂以及BiOCl/C-TiO_(2)复合光催化材料。与纯TiO_(2)相比,球状C-TiO_(2)和BiOCl/C-TiO_(2)的禁带宽度显著降低。以亚甲基蓝为降解目标,当染料质量浓度为25 mg/L、pH为7时,0.1 g BiOCl/CTiO_(2)对其的降解率在1 h可达到81.44%,催化效率达64.15%,其动力学过程符合一级动力学模型。展开更多
基金funded by China Postdoctoral Science Foundation(No.2021M700569)Chongqing Postdoctoral Science Foundation(No.7 cstc2021jcyj-bshX0087)。
文摘This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg alloy.Two kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/Na2SiO3electrolyte.The characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic polarization.It was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and dispersed.The nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in grains.It effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge pores.The MAO coating on Zr-FSP sample had good wettability and corrosion resistance.However,TiO_(2)particles were hardly detected in the coating on TiFSP sample.
基金the Open Project of State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferrometallurgy,China(No.SKLASS2019-11)the National Natural Science Foundation of China(No.52104305).
文摘The phase diagram of ZrO_(2)−CaO−TiO_(2)system was essential for the development of photocatalytic materials and refractory materials.In this work,the ZrO_(2)−CaO−TiO_(2)system was accessed by using the CALPHAD method.The substitutional solution models were used to describe liquid and solid solution phases,the sub-lattice models were used to describe ternary compounds,and then the thermodynamic parameters were obtained by the least square method combined with literature experiment results.The acquired thermodynamic parameters were used to calculate the isothermal sections of the ZrO_(2)−CaO−TiO_(2)system at 1473 and 1673 K.There existed a good agreement between experimental and predicted phase relationships,the experimental points which were inconsistent with calculated results may be attributed to experimental errors and the sluggish kinetics of cations for ZrO_(2)-based materials.In order to further verify the validity of the database,the thermodynamic parameters were also used to simulate the thermodynamic properties(specific heat capacity,enthalpy,and entropy)of CaZrTi_(2)O_(7) within 5%errors.Good consistency demonstrated that the present thermodynamic database was self-consistent and credible.
文摘通过溶剂热法制备了球状C-TiO_(2)催化剂以及BiOCl/C-TiO_(2)复合光催化材料。与纯TiO_(2)相比,球状C-TiO_(2)和BiOCl/C-TiO_(2)的禁带宽度显著降低。以亚甲基蓝为降解目标,当染料质量浓度为25 mg/L、pH为7时,0.1 g BiOCl/CTiO_(2)对其的降解率在1 h可达到81.44%,催化效率达64.15%,其动力学过程符合一级动力学模型。
