The ceramic coatings containing zirconium dioxide were grown in-situ on LY12 aluminium alloy by micro-arc oxidation in mixed zirconate and phosphate solution. The phase composition and morphology of the coatings were ...The ceramic coatings containing zirconium dioxide were grown in-situ on LY12 aluminium alloy by micro-arc oxidation in mixed zirconate and phosphate solution. The phase composition and morphology of the coatings were studied by XRD and SEM. The adhesive strength of ceramic coatings was assessed by thermal shock test and tensile test. The results show that the coating is composed of m-ZrO2,t-ZrO2, and a littleγ-Al2O3. Along the section of the coating, t-ZrO2 is more on both sides than that in the middle, while m-ZrO2 is more in the middle than that on both sides. Meantime the coating is also composed of a dense layer and a loose layer. The coating has excellent thermal shock resistance under 550℃and 600℃. And tensile tests show the adhesive strength of the dense layer of the coating with the substrate is more than 17.5 MPa.展开更多
Micro-laminated ZrO2-Al2O3 coatings were prepared by electrochemical depositing ZrO2 film and Al2O3 film alternatively in ethanol solutions containing aluminum nitrate and zirconium nitrate, with small amounts of (yt...Micro-laminated ZrO2-Al2O3 coatings were prepared by electrochemical depositing ZrO2 film and Al2O3 film alternatively in ethanol solutions containing aluminum nitrate and zirconium nitrate, with small amounts of (yttrium) nitrate added respectively into both solutions. The micro-laminated ZrO2-Al2O3 coating is of nanostructure. FE-SEM analyses show that the cross section of the micro-laminated coatings has alternate six-layer films of ZrO2 and Al2O3, with the thickness of each layer in the range of nanometer or submicron. The surface of the (micro-)(laminated) coatings is composed of nano-particles. SEM, XRD and mass gain measurement were adopted to study the oxidation resistance of coatings on stainless steel. It has been found that all the coatings are effective in protecting the substrate from oxidation, and micro-laminated coatings exhibit more excellent protectiveness performance. Mechanisms accounting for such effects have been discussed.展开更多
基金Project(50171026) supported by the National Natural Science Foundation of ChinaProject (SKLT04-08) supported by the State Key Laboratory of Tribology, Tsinghua University, China
文摘The ceramic coatings containing zirconium dioxide were grown in-situ on LY12 aluminium alloy by micro-arc oxidation in mixed zirconate and phosphate solution. The phase composition and morphology of the coatings were studied by XRD and SEM. The adhesive strength of ceramic coatings was assessed by thermal shock test and tensile test. The results show that the coating is composed of m-ZrO2,t-ZrO2, and a littleγ-Al2O3. Along the section of the coating, t-ZrO2 is more on both sides than that in the middle, while m-ZrO2 is more in the middle than that on both sides. Meantime the coating is also composed of a dense layer and a loose layer. The coating has excellent thermal shock resistance under 550℃and 600℃. And tensile tests show the adhesive strength of the dense layer of the coating with the substrate is more than 17.5 MPa.
文摘Micro-laminated ZrO2-Al2O3 coatings were prepared by electrochemical depositing ZrO2 film and Al2O3 film alternatively in ethanol solutions containing aluminum nitrate and zirconium nitrate, with small amounts of (yttrium) nitrate added respectively into both solutions. The micro-laminated ZrO2-Al2O3 coating is of nanostructure. FE-SEM analyses show that the cross section of the micro-laminated coatings has alternate six-layer films of ZrO2 and Al2O3, with the thickness of each layer in the range of nanometer or submicron. The surface of the (micro-)(laminated) coatings is composed of nano-particles. SEM, XRD and mass gain measurement were adopted to study the oxidation resistance of coatings on stainless steel. It has been found that all the coatings are effective in protecting the substrate from oxidation, and micro-laminated coatings exhibit more excellent protectiveness performance. Mechanisms accounting for such effects have been discussed.
基金Project (gf200901002) support by the National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of Nanchang Hangkong University,China
基金Project(gf200901002)supported by the Open Research Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of Nanchang Hangkong University,China