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建筑用5082铝合金表面等离子烧结SiC-Al2O3涂层性能分析

Surface Modification of 5082 Al-Alloy with Plasma Sintered SiC-Al2O3 Coatings

  • 摘要: 采用等离子烧结方法在建筑用5082铝合金基体上制得SiC-Al2O3涂层,通过实验测试的方式对其涂层制备过程及性能进行分析,并与采用微弧氧化方法得到的Al2O3涂层相比。研究结果表明:当提高电流密度后SiC-Al2O3涂层达到了更优的表面状态,形成尺寸更大球形颗粒,获得了更高的致密度。SiC-Al2O3涂层厚度接近100μm。SiC-Al2O3涂层内各元素含量表现为梯度分布,SiC比例随深度增大而逐渐降低,Al2O3比例出现了升高。当制备时间提高后,在制备期间发生了电压上升,尤其是在初始阶段电压发生了快速增长。当电流密度提高后,SiC-Al2O3涂层可以达到更高的电压,SiC-Al2O3涂层可以达到更高的临界起弧电压。制备时间增加后,涂层形成了更大的厚度,SiC-Al2O3涂层达到比Al2O3涂层更大厚度,显著提升涂层制备效率。相比较微弧氧化Al2O3涂层,等离子烧结SiC-Al2O3涂层获得更高的硬度。

     

    Abstract: The surfaces of 5082 Al-alloy,a window & door material,were modified with SiC-Al2O3 coatings deposited by plasma sintering.The influence of the pulsed DC current on the microstructures and tribological properties was investigated with scanning electron microscopy and mechanical probes.The results show that the current had a major impact.To be specific,as the current density increased,the compactness,spherical grain-size,wear-resistance and interfacial adhesion of the~100 μm thick SiC-Al2O3 coatings increased; the voltage on SiC-Al2O(3)coatings increased,resulting in an increase of glow-discharge onset voltage and fast initial deposition-rate.The SiC-Al2O(3)coatings comprised a decreasing SiC and an increasing Al2O3 depth profiles.The SiC-Al2O3 coating thickness increased with an increase of deposition time.The plasma sintering technique outperforms the micro arc oxidation(MAO) method because of the stronger hardness,larger thickness and greater surface modification efficiency.

     

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