摘要
目的提高铝合金钻杆材料微弧氧化膜层的性能。方法在电解液中加入0~4 g/L的SiC微粉,对7E04铝合金钻杆材料表面生成的微弧氧化膜层进行改性,研究了微弧氧化膜层的氧化电压-时间曲线、厚度、显微硬度、表面形貌、膜层元素含量、相组成和耐蚀性。结果随着SiC微粉质量浓度的增加(0、1、2、3、4 g/L),氧化电压不断增加,在4 g/L时几乎达到550 V。微弧氧化膜层的厚度和显微硬度增加,各浓度下的膜层厚度分别为42.3、43.6、45.0、45.3、50.0μm,膜层显微硬度分别为341.8、375.2、394.4、405.1、436.8MPa。同时,放电孔的孔径和烧结盘的尺寸也逐渐增加。在微弧氧化过程中,SiC被氧化成SiO_2,基体中的Al被氧化成α-Al_2O_3和γ-Al_2O_3,膜层中的相组成主要有α-Al_2O_3、γ-Al_2O_3、SiO_2和莫来石。同时,随着SiC微粉浓度的增加,膜层中的C、Si元素含量增加,Al元素和O元素的含量降低。膜层的腐蚀速率分别为1.11×10^(-1)、3.598×10^(-2)、5.223×10^(-2)、6.762×10^(-2)、1.323×10^(-1) mm/a,呈现出先减小后增加的趋势,耐蚀性先增加后降低。结论 SiC微粉的添加增加了膜层的厚度,改变了膜层的表面形貌,同时提高了微弧氧化膜层的显微硬度、耐蚀性等性能。
The work aims to improve properties of micro-arc oxidation（MAO） coatings on aluminum alloy drill pipe material. Micro-arc oxidation（MAO） coatings on 7 E04 aluminum alloy drill pipe material were modified by adding 0 to 4 g/L SiC micro-particles in electrolytes. Oxidation voltage-time curve, thickness, microhardness, surface morphology, content of coating element, phase composition and corrosion resistance of the MAO coatings were studied. With the increase of SiC micro-particle concentration（0, 1, 2, 3, 4 g/L）, oxidation voltage rose gradually and nearly reached 550 V at the concentration of 4 g/L. The thickness and microhardness of MAO coatings increased along with oxidation voltage. Thickness of the MAO coatings at each concentration was 42.3, 43.6, 45.0, 45.3 and 50.0 μm, respectively, and microhardness of the coatings were 341.8, 375.2, 394.4, 405.1, 436.8 MPa, respectively. Meanwhile, diameter of discharge pore and size of sintered disc also increased gradually. In the MAO process, SiC was oxidized into SiO2, Al in the substrate was oxidized into α-Al2O3 and γ-Al2O3, and the MAO coatings were mainly composed of α-Al2O3, γ-Al2O3, SiO2 and mullite phase. In the meantime, as SiC micro-particle concentration increased, the content of C and Si rose, while the content of O and Al decreased. Corrosion rate of the coatings was 1.11×10^-1, 3.598×10^-2, 5.223×10^-2, 6.762×10^-2, 1.323×10^-1 mm/a, respectively, the corrosion rate first dropped and then increased, while corrosion resistance first increased and then dropped. The addition of SiC micro-particle has increased thickness of coatings, changed surface morphology of coatings, and enhanced properties（such as microhardness and corrosion resistance） of MAO coatings.
作者
王平
曹文洁
蒲俊
龚泽宇
胡杰
肖佑涛
WANG Ping;CAO Wen-jie;PU Jun;GONG Ze-yu;HU Jie;XIAO You-tao(Southwest Petroleum University, Chengdu 610500, China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2018年第6期63-67,共5页
Surface Technology
基金
西南石油大学科研启航项目(2015QHZ020)~~
关键词
微弧氧化
铝合金钻杆
微观结构
SIC微粉
耐蚀性
反应机理
micro-arc oxidation
aluminum alloy drill pipe
microstructure
SiC micro-particles
corrosion resistance
reaction mechanism
