不同pH值环境中镍铝青铜冷喷涂涂层腐蚀磨损性能

发布时间：2018-04-28 15:35

本文选题：镍铝青铜 + 冷喷涂　；参考：《工程科学学报》2017年07期

【摘要】：镍铝青铜合金是铸造大型舰艇螺旋桨的主要材料,海洋污损生物在合金表面附着引起的pH值变化会加速镍铝青铜合金的腐蚀磨损,威胁到舰艇安全航行.采用冷喷涂技术制备了较为致密的镍铝青铜涂层,厚度约300μm,利用扫描电镜、光学显微镜观察了涂层的微观形貌,重点研究了涂层在pH值分别为3、7和11,质量分数为3.5%的Na Cl溶液中的电化学腐蚀性能和腐蚀磨损行为.实验结果表明:pH值为3的环境中,镍铝青铜基体发生了选相腐蚀,表面疲劳裂纹主要分布在富Cu的α相上,涂层上的犁削沟槽加深发生了磨粒磨损,涂层耐腐蚀性能优于基体;pH值为7的环境中,基体发生了黏着磨损,表面有片层状金属剥落,涂层中的孔隙收容了大量磨屑避免了剧烈的三体摩擦,表面犁削沟槽较浅,涂层致钝电位高于基体,耐腐蚀性能变差.pH值为11的环境中,基体发生了表面疲劳磨损,涂层磨痕上有较深的犁削沟槽,沟槽内有微裂纹,涂层耐腐蚀性能优于基体.总体来说,在不同pH值环境中,涂层由于在冷喷涂过程中发生了冷加工硬化并且涂层上的孔隙收容了磨屑,导致涂层的耐腐蚀磨损性能增强.
[Abstract]:Nickel aluminum bronze alloy is the main material for casting large ship propeller. The change of pH value caused by the adhesion of marine fouling organisms on the alloy surface will accelerate the corrosion and wear of nickel aluminum bronze alloy and threaten the safe navigation of the ship. A dense Ni-Al bronze coating with a thickness of about 300 渭 m was prepared by cold spraying technique. The microstructure of the coating was observed by scanning electron microscope and optical microscope. The electrochemical corrosion behavior and corrosion wear behavior of the coating in NaCl solution with pH value of 3 ~ 7 and mass fraction of 3.5% were studied. The experimental results show that in the environment of pH 3, selective corrosion occurs in the Ni-Al bronze matrix, the surface fatigue cracks are mainly distributed on the Cu rich 伪 phase, and abrasive wear occurs in the ploughing groove of the coating. The corrosion resistance of the coating is better than that of the substrate with pH value of 7, the substrate has adhesive wear, the surface of the coating has a sheet of layered metal exfoliation, the pores in the coating contain a large amount of debris to avoid severe three-body friction, and the surface ploughing groove is shallow, and the corrosion resistance of the coating is better than that of the substrate with pH value of 7. The corrosion resistance of the coating is better than that of the substrate. In the environment of poor corrosion resistance and pH value of 11, the substrate has surface fatigue wear, deep ploughing grooves and microcracks in the wear trace of the coating. The corrosion resistance of the coating is better than that of the substrate. Generally speaking in different pH environment the corrosion and wear resistance of the coating is enhanced due to the cold working hardening and the pores of the coating receiving debris during the cold spraying process.
【作者单位】：装甲兵工程学院装备维修与再制造工程系;
【基金】：军内科研基金资助项目
【分类号】：TG174.4

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