反向挤压铝合金棒材尾端中心粗晶的成因分析

摘要

通过偏光组织、高倍组织等方法对LD5合金反挤压棒材尾部的漏斗状缩尾和中心粗晶的形成作了分析探讨。根据反挤压时金属变形特点分析出中心粗晶的成因是挤压后端死区的存在及流动的金属受堵头的磨擦和冷却作用，使反挤压后期金属流动不均所致。%The cause of funnel-shaped shrinkage tails and central coarse grains of LD5 aluminum al-loy rods during inverted extrusion was researched by polarization analysis and microstructure analysis. Based on characteristics of metal deformation during inverted extrusion, the analysis shows that the cause of coarse grains is the uneven metal flow during the late stage of inverted extrusion due to the dead zone at the extrusion tail and the influence of end friction and cooling on the flowing metal.