微弧氧化及硬质阳极氧化对7050铝合金表面氧化膜层的影响

为了比较微弧氧化和硬质阳极氧化对铝合金表面性能的影响,对7050铝合金试样分别进行微弧氧化及硬质阳极氧化处理,利用X射线衍射仪、扫描电子显微镜、显微硬度计等分析了7050铝合金微弧氧化陶瓷层与硬质阳极氧化陶瓷层的物相组成、显微组织及显微硬度,并用摩擦磨损试验机对微弧氧化陶瓷层与硬质阳极氧化陶瓷层进行磨损性能研究。结果表明:微弧氧化陶瓷层的磨痕深度小于硬质阳极氧化陶瓷层的磨痕深度,而微弧氧化陶瓷层的平均磨损失重大于硬质阳极氧化陶瓷层的平均磨损失重,这是因为微弧氧化陶瓷层主要由Al、α-Al2O3、γ-Al2O3相组成,其密度较大,而硬质阳极氧化陶瓷层主要由非晶Al2O3组成,其密度较小。因此,在相同条件下通过Tabel摩擦磨损试验来比较微弧氧化陶瓷层与硬质氧化膜层的耐磨性时,应以相同条件下,相同磨损转数时,由剩余膜层的厚度来衡量。

Influence of Micro-Arc Oxidation and Hard Anodic Oxidation on the Surface Oxidation Ceramic Coating of 7050 Aluminium Alloy

In order to compare the influences of micro-arc oxidation and hard anodic oxidation on the surface performance of aluminium alloy,the samples of 7050 aluminium alloy were treated by micro-arc oxidation and hard anodic oxidation,respectively.The phase composition,microstructures and microhardness of micro-arc oxidation ceramic layer and hard anodic oxidation ceramic layer were analyzed by X-ray diffraction,scanning electron microscopy and microhardness tester.In addition,the wear properties of both layers were studied by friction and wear tester.Results showed that the wear trace depth of micro-arc oxidation ceramic layer was less than that of hard anodic oxidation ceramic layer,while the average wear loss of micro-arc oxidation ceramic layer was more than that of hard anodic oxidation ceramic layer,which resulted from the composition of layers:the micro-arc oxidation ceramic layer with a high density was mainly composed of Al,α-Al2O3 andγ-Al2O3,while the hard anodized ceramic layer with a low density was mainly composed of amorphous Al2 O3.Therefore,when the wear resistance of micro-arc oxidation ceramic layer and hard anodic oxidation ceramic layer was compared under the same conditions through Tabel friction and wear tester,it was reasonable to measure the thickness of residual layers under similar wearing turn numbers.