挤压铝型材表面拉毛形成原因分析

Analysis on Forming Cause of Extruded Aluminum Profile Surface Roughening

采用直读光谱仪、扫描电镜等设备,通过分析合金成分、挤压工艺、铸棒表面质量对型材拉毛缺陷的影响,研究拉毛形成的原因。结果表明,拉毛缺陷前端有明显沿挤压方向台阶状划伤痕迹,收尾瘤状颗粒形状不规则;成分与基体接近,其周围分布Fe、Si、C、O含量高的异质颗粒;挤压速度过快,挤压出口温度过高,铸棒表面粗糙都会加剧表面拉毛的产生。

In this paper,direct reading spectrometer,scanning electron microscope and other equipment are used to analyze the influence of alloy composition,extrusion process and casting bar surface quality on the galling defects of the profiles,and the cause of galling defect is studied.The results showed that there are obvious step scratches along the extrusion direction at the front end of the drawing defect,and the shape of the final nodular particle is irregular.The composition is close to the matrix and heterogeneous particles with high Fe,Si,C and O content are distributed around it.The extrusion speed is too fast,the extrusion outlet temperature is too high,and the casting rod surface roughness will aggravate the appearance of surface drawing.