(1. 南昌航空大學(xué) 輕合金加工科學(xué)與技術(shù)國(guó)防重點(diǎn)學(xué)科實(shí)驗(yàn)室，南昌 330063；
2. 中國(guó)航發(fā)貴州黎陽(yáng)航空動(dòng)力有限公司，黎陽(yáng) 550014；
3. 北京科技大學(xué) 腐蝕與防護(hù)中心，北京 110083)
摘 要: 在硅酸鹽和磷酸鹽混合電解液體系中加入不同粒徑HBN顆粒，通過(guò)等離子體氧化法(PEO)在7075-T6合金表面制備Al2O3/HBN復(fù)合膜；利用SEM、EDS、XRD、磨損實(shí)驗(yàn)、電化學(xué)極化曲線等對(duì)復(fù)合膜的組織結(jié)構(gòu)、化學(xué)組成、耐磨及耐蝕性能進(jìn)行表征。結(jié)果表明：HBN顆粒加速了膜層的擊穿放電過(guò)程，對(duì)PEO膜的前期生長(zhǎng)有促進(jìn)作用，且所得膜層較為致密，但膜層粗糙度有所增加。電解液中加入4g/L的HBN顆粒，無(wú)論HBN粒徑為5、10或30 μm，均能使PEO膜的表層微孔數(shù)量及內(nèi)部缺陷有所減少，且復(fù)合膜中晶態(tài)Al2O3相含量也有所增長(zhǎng)。相比于PEO膜，HBN顆粒復(fù)合的PEO/HBN復(fù)合膜的摩擦因數(shù)更小、比磨損率更低、摩擦磨損性能均有所改善；且HBN粒徑為10 μm時(shí)，復(fù)合膜的耐磨性更佳，比磨損率降低近42.5%。此外，PEO/HBN復(fù)合膜的耐蝕性更優(yōu)，其自腐蝕電流密度較未復(fù)合的PEO膜下降了1個(gè)數(shù)量級(jí)；5 μm粒徑HBN復(fù)合的膜層經(jīng)模擬海水浸泡1800 h后表面腐蝕較輕微。
關(guān)鍵字: 7075-T6合金；PEO；HBN顆粒；微觀結(jié)構(gòu)；性能
（1. National Defense Key Discipline Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang 330063, China;
2. AECC Guizhou Liyang Aviation Power Co., Ltd., Liyang 550014, China;
3. Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Al2O3 /HBN composite coatings were prepared on 7075-T6 aluminum alloy by plasma electrolysis oxidation (PEO) in silicate-phosphate mixed electrolyte with HBN particles of different sizes. The microstructure, composition, wear resistance and corrosion resistance of the composite coating were analyzed by SEM, EDS, XRD, wear test and polarization curves. The results show that HBN particles can accelerate the breakdown discharge process of coating, and promote the pre-growth stage of PEO coating. The incorporation of HBN particles also makes PEO coating more dense, but increase the roughness. Whether HBN particle size is 5, 10 or 30 μm, the addition of 4 g/L HBN particles in the electrolyte can reduce the surface micropores number and the internal defects of PEO coating, and make the coating surface be flatter. The content of Al2O3 crystal phase in the PEO composite coatings also increases. Compared with PEO coating, the PEO/HBN composite coatings have smaller friction coefficient, lower wear rate and better wear properties. Among them, the PEO composite coating prepared in electrolyte containing 10 μm HBN particles shows the best wear resistance, and the specific wear rate decreases by 42.5%. Besides, the PEO/HBN composite coatings have better corrosion resistance, the corrosion current density is one order of magnitude lower than that of the uncomposited PEO coating, and the surface corrosion of PEO sample prepared in electrolyte with 5 μm HBN particles is the slightest after 1800 h simulated seawater immersion test.
Key words: 7075-T6 alloy; PEO; HBN particles; micro-structure; performances
