扫描速率对激光重熔微弧氧化层组织性能影响研究

Effect of Scanning Rate on Microstructure and Properties of Laser Remelted Micro-arc Oxide Layer

为了提高汽车车身用铝合金的表面力学性能,设计了复合工艺的加工处理,通过微弧氧化(MAO)和激光重熔(LR)技术对6061铝合金表面进行复合处理。通过调节激光扫描速度,制备具有良好力学性能的6061合金表面陶瓷(α-Al_(2)O_(3))层。研究结果表明,经LR、MAO复合处理后,致密层主要为比较稳定的α-Al_(2)O_(3)相,疏松层为亚稳态的Mg_(3)Al_(2)(SiO_(4))_(3)和Mg_(2)Si相构成,复合处理有效改善了材料组织结构。此次使用MAO与LR复合工艺制备的表面陶瓷层显微硬度显著提高,平均硬度最高可达220 HV,陶瓷层结合强度随扫描速度增加先上升后降低并且材料表面亲水性降低。

In order to improve the surface mechanical properties of aluminum alloy for automobile body,a composite process was designed.The surface of aluminum alloy 6061 aluminium alloy was treated by micro-arc oxidation(MAO) and laser remelting(LR).α-Al_(2)O_(3) layer on 6061 alloy with good mechanical properties was prepared by adjusting the laser scanning speed.The results showed that the compacted layer was mainly composed of α-Al_(2)O_(3),and the loose layer was composed of metastable Mg_(3)Al_(2)(SiO_(4))_(3) and Mg_(2)Si phases after LR-MAO composite treatment.The microhardness of the surface ceramic layer prepared by the composite process of Mao and LR was significantly increased,and the average hardness was up to 220 HV,the bonding strength of the ceramic layer increased first and then decreased with the increase of scanning velocity,and the surface hydrophilicity of the material decreased.