Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment
The effects of CuSO<sub>4</sub> concentration, voltage and treating time on the hemisphere emissivity and corrosion resistance of AZ31B magnesium-alloy black micro-arc oxidation coatings were studied by orthogonal experiment. The microstructure, phase composition, corrosion resistance an...
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MDPI AG
2022-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/24/8755 |
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| author | Hongzhan Li Yifei Wang Juanjuan Geng Shaolong Li Yongnan Chen |
| author_facet | Hongzhan Li Yifei Wang Juanjuan Geng Shaolong Li Yongnan Chen |
| author_sort | Hongzhan Li |
| collection | DOAJ |
| description | The effects of CuSO<sub>4</sub> concentration, voltage and treating time on the hemisphere emissivity and corrosion resistance of AZ31B magnesium-alloy black micro-arc oxidation coatings were studied by orthogonal experiment. The microstructure, phase composition, corrosion resistance and hemisphere emissivity of the coating were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical test and infrared emissivity spectrometer, respectively. The results showed that the influences of each factor on corrosion current density and the hemisphere emissivity are as follows: voltage > treating time > CuSO<sub>4</sub> concentration. The black MAO coatings are mainly composed of WO<sub>3</sub>, MgAl<sub>2</sub>O<sub>4</sub>, CuAl<sub>2</sub>O<sub>4</sub>, MgO, CuO and MgF<sub>2</sub>. The CuO and CuAl<sub>2</sub>O<sub>4</sub> phases are the main reasons for blackness of the coatings. The coating exhibits the best corrosion resistance under the conditions of CuSO<sub>4</sub> concentration 1.5 g/L, oxidation voltage 500 V and treating time 10 min. Additionally, the variation trends of hemispherical emissivity and roughness of the black MAO coating are the same when the composition of the coatings is similar. When the concentration of CuSO<sub>4</sub> is 1.5 g/L, the oxidation voltage is 450 V and the treatment time is 10 min, the coating with the highest hemispherical emissivity of 0.84 can be obtained. |
| first_indexed | 2024-03-09T16:09:51Z |
| format | Article |
| id | doaj.art-3cc01aed72bb4e23b6d83068523a991a |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T16:09:51Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-3cc01aed72bb4e23b6d83068523a991a2023-11-24T16:21:04ZengMDPI AGMaterials1996-19442022-12-011524875510.3390/ma15248755Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal ExperimentHongzhan Li0Yifei Wang1Juanjuan Geng2Shaolong Li3Yongnan Chen4Northwest Institute for Nonferrous Metal Research, Xi’an 710016, ChinaNorthwest Institute for Nonferrous Metal Research, Xi’an 710016, ChinaNorthwest Institute for Nonferrous Metal Research, Xi’an 710016, ChinaNorthwest Institute for Nonferrous Metal Research, Xi’an 710016, ChinaSchool of Materials Science and Engineering, Chang’an University, Xi’an 710064, ChinaThe effects of CuSO<sub>4</sub> concentration, voltage and treating time on the hemisphere emissivity and corrosion resistance of AZ31B magnesium-alloy black micro-arc oxidation coatings were studied by orthogonal experiment. The microstructure, phase composition, corrosion resistance and hemisphere emissivity of the coating were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical test and infrared emissivity spectrometer, respectively. The results showed that the influences of each factor on corrosion current density and the hemisphere emissivity are as follows: voltage > treating time > CuSO<sub>4</sub> concentration. The black MAO coatings are mainly composed of WO<sub>3</sub>, MgAl<sub>2</sub>O<sub>4</sub>, CuAl<sub>2</sub>O<sub>4</sub>, MgO, CuO and MgF<sub>2</sub>. The CuO and CuAl<sub>2</sub>O<sub>4</sub> phases are the main reasons for blackness of the coatings. The coating exhibits the best corrosion resistance under the conditions of CuSO<sub>4</sub> concentration 1.5 g/L, oxidation voltage 500 V and treating time 10 min. Additionally, the variation trends of hemispherical emissivity and roughness of the black MAO coating are the same when the composition of the coatings is similar. When the concentration of CuSO<sub>4</sub> is 1.5 g/L, the oxidation voltage is 450 V and the treatment time is 10 min, the coating with the highest hemispherical emissivity of 0.84 can be obtained.https://www.mdpi.com/1996-1944/15/24/8755AZ31B magnesium alloymicro-arc oxidationblack MAO coatingorthogonal experimentcorrosion resistancehemisphere emissivity |
| spellingShingle | Hongzhan Li Yifei Wang Juanjuan Geng Shaolong Li Yongnan Chen Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment Materials AZ31B magnesium alloy micro-arc oxidation black MAO coating orthogonal experiment corrosion resistance hemisphere emissivity |
| title | Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment |
| title_full | Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment |
| title_fullStr | Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment |
| title_full_unstemmed | Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment |
| title_short | Study on Microstructure and Properties of Black Micro-Arc Oxidation Coating on AZ31 Magnesium Alloy by Orthogonal Experiment |
| title_sort | study on microstructure and properties of black micro arc oxidation coating on az31 magnesium alloy by orthogonal experiment |
| topic | AZ31B magnesium alloy micro-arc oxidation black MAO coating orthogonal experiment corrosion resistance hemisphere emissivity |
| url | https://www.mdpi.com/1996-1944/15/24/8755 |
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