不同热处理对Al-5.6Mg合金板材表面组织和阳极氧化膜组织的影响

The Effect of Different Heat Treatments on Surface Microstructures and Anodic Oxide Film Structures of an Al-5.6Mg Alloy Sheets

摘要:

本文研究了不同中间退火热处理对Al-5.6Mg合金轧制薄板表面组织和阳极氧化膜组织的影响。结果表明:在中间退火过程中，用连续退火代替箱式退火，试样表面晶粒尺寸可减小约60%，Mg析出相 (Mg2Al3)尺寸可减小约67%;在晶粒尺寸、析出相和织构的共同影响下，经连续中间退火和低温稳定化退火后阳极氧化，获得了最高的光泽度。均匀的微观结构有利于减少氧化膜的不均匀溶解，获得厚度均匀、光泽度高的阳极氧化膜。

关键词:热处理、阳极氧化、al-Mg合金，微观结构

Abstract:

The effect of different intermediate annealing heat treatments on the surface microstructures and anodic oxide film structures of rolled sheets of an Al-5.6Mg alloy was studied. The results show that when the continuous annealing is used instead of the static state annealing in intermediate annealing process to control microstructures of the sheets, the surface grain size of the sheets can be reduced by about 60 %, and size of the Mg precipitated phase (Mg2Al3) can be reduced by about 67 %. Under the combined influence of grain size, uniform precipitation phase, and texture, the highest glossiness can be obtained, which was attributed to continuous intermediate annealing and stabilization annealing at low temperature. The uniform grain and precipitation structures is beneficial to reduce the inhomogeneous dissolution of the oxide film and to obtain the anodic oxide film with uniform thickness and high gloss.

Key words:Heat;treatment, Anodizing, Al-Mg;alloy, Microstructures