| HUI Jie,SUN Chang-fei,MA Chun-sheng.Effects of Negative Voltage on the Preparation and Wear Resistance of ZL109 Aluminum Alloy Micro-arc Oxidation Ceramic Layers under the Action of Nickel-coated Carbon Nanotubes Additive[J],52(4):202-209 |
| Effects of Negative Voltage on the Preparation and Wear Resistance of ZL109 Aluminum Alloy Micro-arc Oxidation Ceramic Layers under the Action of Nickel-coated Carbon Nanotubes Additive |
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| DOI：10.16490/j.cnki.issn.1001-3660.2023.04.017 |
| KeyWord:cast aluminum alloy micro-arc oxidation negative voltage wear-resisting property magnetic nanoparticles electrolyte additives nickel-plated carbon nanotubes |
| Author | Institution |
| HUI Jie |
Department of Marine Electrical and Intelligent Engineering, Jiangsu Maritime Vocational and Technical College, Nanjing , China |
| SUN Chang-fei |
Department of Marine Electrical and Intelligent Engineering, Jiangsu Maritime Vocational and Technical College, Nanjing , China |
| MA Chun-sheng |
Shenzhen Research Institute of Dalian Maritime University, Guangdong Shenzhen , China;Department of Marine Engineering, Dalian Maritime University, Liaoning Dalian , China |
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| Abstract: |
| In order to further improve the reliability and durability of key cast aluminum alloy parts, promote the development of micro-arc oxidation surface treatment technology, and explore the influence of positive and negative voltage of power supply with new micro-arc oxidation magnetic nanoparticles electrolyte additives on micro-arc oxidation ceramic layers. In this work, single factor control method is adopted, the negative voltage of micro-arc oxidation power supply is set as:100 V, 110 V, 120 V, 130 V, 140 V, 150 V, 160 V, and 0.8 g/L nickel-plated carbon nanotubes additive is introduced into the electrolyte system, the micro-arc oxidation ceramic layers are analyzed by scanning electron microscope, optical profilometer, X-ray photoelectron spectroscopy, X-ray diffraction and a self-made reciprocating friction and wear testing machine in terms of micro morphology, thickness, surface roughness, compactness, porosity and pore size analysis and wear resistance property, the effects of negative voltage of micro-arc oxidation power supply on the preparation and wear resistance of ZL109 aluminum alloy micro-arc oxidation ceramic layers are analyzed. In this paper, the micro-arc oxidation ceramic layers are prepared by a bipolar pulsed micro arc oxidation power supply. On the basis of the previous research results, the positive voltage varying by stages is good for preparing composite coatings. Therefore, in this work, the positive voltage of power supply is controlled manually in three stages:360 V for 1-5 min, 400 V for 6-10 min, 440 V for 11-15 min. The total reaction time was 15 min. The composition of the electrolyte is:4 g/L Na2SiO3, 4 g/L Na2WO3, 2 g/L KOH and 2 g/L EDTA-2Na. When the negative voltage is less than 110 V, large deep holes are unevenly distributed on the surface of the ceramic layers. When the negative voltage reaches 120 V, the porosity of the ceramic layers increases obviously, and relatively small deep pores are evenly distributed on the surface. However, when the negative voltage reaches 130 V and above, the surface of the ceramic layers is replaced by a large number of shallow pores with relatively uniform distribution. The main elements of the prepared ceramic layers are oxygen, aluminum, silicon and carbon, and the main phases are α-Al2O3 and γ-Al2O3. In the reciprocating friction and wear tests, the ceramic layer prepared with negative voltage of 100 V shows overall wear on the surface, and the wear resistance of the ceramic layer is relatively poor, and the actual contact area of the friction pair is increased, so the friction coefficient is high. The friction coefficient of ceramic layers obtained by other negative voltages basically remained at about 0.4, among which, the friction coefficient of ceramic layer prepared by negative voltages 140 V is low, with small fluctuation and low wear. The wear surface morphology shows that the ceramic layer is only slightly worn locally, and the ceramic layer can basically keep the original surface morphology. The ceramic layer prepared with negative voltage 140 V has good compactness, low surface roughness (Ra, 0.77 μm), the surface porosity is 2.05%, the average pore size is 0.594 μm, a certain thickness (11.5 μm) and good wear resistance (The wear loss is 0.13 mg). The results show that there is a synergistic relationship between nickel-coated carbon nanotubes and the positive and negative voltage of the power supply on the micro-arc oxidation reaction, the negative voltage has a significant effect on the micro-arc oxidation reaction process, the micro morphology, thickness, compactness and surface roughness of the ceramic layers. |
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