2024-T3铝合金表面三价铬化学转化膜的制备及其性能  

Process and Properties of Trivalent Chromium Chemical Conversion Film on 2024-T3 Aluminum Alloy Surface

作　　者：李嘉烁 王梅丰[1] 黄小文 陈东初[3] 王夏妍 LI Jiashuo;WANG Meifeng;HUANG Xiaowen;CHEN Dongchu;WANG Xiayan(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,China;AVIC Jiangxi Hongdu Aviation Industry Group Co.,Ltd.,Nanchang 330096,China;School of Materials Science and Hydrogen Energy,Foshan University,Foshan 528137,China)

机构地区：[1]南昌航空大学材料科学与工程学院,南昌330063 [2]航空工业江西洪都航空工业集团有限责任公司,南昌330096 [3]佛山科学技术学院材料科学与氢能学院,佛山528137

出　　处：《腐蚀与防护》2025年第4期100-107,共8页Corrosion & Protection

摘　　要：开发了以K_(2)ZrF_(6)、Cr(OH)SO_(4)为主盐,NH-2为添加剂的2024-T3铝合金三价铬-锆基化学转化膜制备工艺。通过硫酸铜快速点滴试验研究K_(2)ZrF_(6)、Cr(OH)SO_(4)和添加剂NH-2质量浓度,工作液温度,pH以及化学氧化时间对转化膜耐蚀性的影响规律。利用中性盐雾试验(NSS),划格法,场发射扫描电子显微镜(SEM)及能谱仪等测试了转化膜的耐蚀性,漆膜结合力,表面形貌及元素分布等。结果表明:转化液最佳配方为10 g/L K_(2)ZrF_(6)、1.2 g/L Cr(OH)SO_(4)以及0.72 g/L添加剂NH-2,当其pH为3.8时,40℃下氧化5 min制备的转化膜的耐蚀性较为优良。转化膜在168 h连续中性盐雾试验中未发生腐蚀,漆膜结合力为0级;转化膜是由无数连续的直径数十纳米的颗粒组成的,可对基体进行保护;膜层主要由O、Al、Cu、Mg、Zr、Cr、F等元素组成;膜层中的Cr元素为三价铬,不含六价铬,是一种环保的铝合金化学氧化工艺。A trivalent chromium zirconium based chemical conversion process film preparation process on 2024-T3 aluminum alloy was developed,with K_(2)ZrF_(6) and Cr(OH)SO_(4) as the main salts and NH-2 as an additive.The influence of K_(2)ZrF_(6),Cr(OH)SO_(4),and NH-2 additive mass concentration,working fluid temperature,pH,and chemical oxidation time on the corrosion resistance of the conversion film was studied through a rapid drop test of copper sulfate.The corrosion resistance,film adhesion,surface morphology,and element distribution of the conversion film were tested using neutral salt spray test(NSS),grid cut method,field emission scanning electron microscopy(SEM),and energy dispersive spectrometer.The results show that the chemical conversion solution prepared with 10 g/L K_(2)ZrF_(6),1.2 g/L Cr(OH)SO4,and 0.72 g/L additive NH-2 exhibited excellent corrosion resistance when oxidized for 5 minutes at 40℃ and pH 3.8.The conversion film did not corrode during the 168 hour continuous neutral salt spray test.The adhesion strength of the paint film was level 0.The conversion film was composed of countless continuous particles with a diameter of tens of nanometers,which could protect the substrate.The film layer was mainly composed of elements such as O,Al,Cu,Mg,Zr,Cr,F,etc.The Cr element in the film layer was trivalent chromium,without hexavalent chromium,which was an environmentally friendly chemical oxidation process for aluminum alloys.

关 键 词：2024-T3铝合金 化学氧化膜 三价铬-锆 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]