等离子体微弧氧化表面处理LY12铝合金的高温拉伸性能

采用等离子体微弧氧化技术对LY12铝合金表面进行氧化处理,对处理前后材料的高温拉伸性能进行了研究,用SEN观察试样拉伸断口及陶瓷涂层形貌。结果表明:在高温条件下,LY12铝合金表面陶瓷化后拉伸强度有一定提高,且随温度的升高,拉伸强度提高的比率增大,说明在高温条件下陶瓷涂层对铝基体起到了一定的隔热作用;表面陶瓷化对LY12铝合金的延伸率影响不大。试样为典型的韧性断裂,且断裂后陶瓷膜层没有出现大面积脱落,表明陶瓷涂层与铝基体结合良好。

High Temperature Tensile Properties of LY12 Aluminum Alloy Processed by Plasma Microarc Oxidation

High temperature tensile properties of LY12 aluminum alloy processed by plasma microarc oxidation are investigated. Fractographs of tensile specimens and surface of ceramic coating are studied by using SEM. The results show that the tensile strength of LY12 aluminum alloy coated with ceramic coating is increased under high temperature. Moreover, the enhanced proportion of tensile strength increases with temperature rise, which indicates that the ceramic coating plays a role in thermal insulation, but elongation of the tensile specimens has no change obviously. Specimens are typical toughness rupture, and there are no large acreage of ceramic-coating spal ling after tensile rupture. It is indicated that the bonding between ceramic coating and matrix is tight.