The cauces of streak defect on6063aluminium alloy extrusion profile are analyzed from the bil-let quality,die structure and extrusion process.Some methods to prevent it are presented.

• 从铝棒质量、模具结构、挤压工艺等方面分析了6063铝合金挤压型材表面产生条纹缺陷的原因,并提出了预防措施。