金属热处理 ›› 2021, Vol. 46 ›› Issue (4): 152-156.DOI: 10.13251/j.issn.0254-6051.2021.04.027

• 工艺研究 • 上一篇    下一篇

硅酸盐体系电解液中添加Na2WO4对LY12铝合金陶瓷膜性能的影响

何巧成, 姜文勇, 陈鹿, 王长亮, 武鹏海   

  1. 哈尔滨理工大学 材料科学与工程学院, 黑龙江 哈尔滨 150040
  • 收稿日期:2020-10-18 出版日期:2021-04-25 发布日期:2021-05-08
  • 通讯作者: 姜文勇,研究员,博士,E-mail:jwy641014@126.com
  • 作者简介:何巧成(1994—),男,硕士研究生,主要研究方向为材料表面改性,E-mail:2810254644@qq.com。

Influence of adding Na2WO4 to electrolyte of silicate system on properties of ceramic film on LY12 aluminum alloy

He Qiaocheng, Jiang Wenyong, Chen Lu, Wang Changliang, Wu Penghai   

  1. School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin Heilongjiang 150040, China
  • Received:2020-10-18 Online:2021-04-25 Published:2021-05-08

摘要: 通过SEM、XRD、硬度试验、电化学腐蚀试验研究了在硅酸盐体系电解液中加入不同浓度的Na2WO4对LY12铝合金微弧氧化陶瓷膜表面形貌及性能的影响。结果表明,添加Na2WO4改变了膜层的微观结构,使微弧氧化膜层硬度增加,表面平滑,呈现出小而少的孔洞结构,且表面堆积少量形状不规则的白色质点;随着Na2WO4添加量的增加,膜层的硬度值呈现先增加后降低的趋势,当Na2WO4含量为4 g/L时,膜层达到最高硬度440.3 HV0.3,较基体(硬度值约168 HV0.3)提升了272.3 HV0.3;XRD分析证明W元素参与了微弧氧化过程,并生成W的氧化物WO3,陶瓷层物相主要由α-Al2O3和γ-Al2O3以及WO3组成;电化学极化曲线分析结果表明添加剂Na2WO4有效地提高了膜层的耐腐蚀性能,耐腐蚀性能最好的添加量为 1 g/L,此时自腐蚀电位为-532.0 mV,腐蚀电流为0.011 μA。Na2WO4的添加可有效改善陶瓷膜层的表面形貌及性能。综合考虑膜层的性能,添加剂Na2WO4的最佳添加量为 4 g/L。

关键词: LY12铝合金, 微弧氧化, 硅酸盐体系, Na2WO4, 陶瓷膜层

Abstract: Na2WO4 additive was added to the electrolyte of silicate system. The effect of concentration of Na2WO4 additive on surface morphology and properties of micro-arc oxidation ceramic film on LY12 aluminum alloy was studied by means of SEM, XRD, hardness test and electrochemical corrosion test. The results show that with the addition of Na2WO4, the microstructure of the film is changed, and the hardness of the film increases, the surface is smooth, and there are fewer small holes and a small amount of irregular white particles on the surface. With the increase of Na2WO4, the hardness of the film increases first and then decreases. When the Na2WO4 content is 4 g/L, the maximum hardness of the film is 440.3 HV0.3, which is increased by 272.3 HV0.3 compared with that of the substrate (about 168 HV0.3). XRD analysis shows that W element participates in the micro-arc oxidation process, and forms oxide WO3. The ceramic layer mainly consists of α-Al2O3, γ-Al2O3 and WO3. The electrochemical polarization curve analysis shows that addition of Na2WO4 effectively improves the corrosion resistance of the film, and the corrosion resistance is the best when the additive amount is 1 g/L, the corrosion potential is -532.0 mV and the corrosion current is 0.011 μA. The addition of Na2WO4 can effectively improve the surface morphology and properties of the ceramic film. The optimal addition amount of the Na2WO4additive is 4 g/L so as to obtain the comprehensive performance of the film.

Key words: LY12 aluminum alloy, micro-arc oxidation, silicate system, Na2WO4, ceramic film

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