6063铝合金内筋管表面水波纹缺陷分析

Analysis of the water ripple defect on the surface of the 6063 aluminum alloy inner rib tube

6063铝合金型材经着色处理后表面出现水波纹缺陷是许多铝材生产企业遇到的问题。以内筋管铝型材为例,通过对挤压组合模腔的精心修整,经过上机挤压试验发现,模具结构是诱发水波纹缺陷的必要条件。对模腔内积存的金属进行解剖、研磨、着色后判断是组织的不均匀造成了型材局部表面紊乱的色差。通过采集铸锭不同部位样本进行化验,确定区域偏析是引起水波纹现象的主要原因。采取加强铸造工艺、变质处理、低温低速挤压等多种工艺手段可消除水波纹现象。

After coloring treatment, the water ripple defect on the surface of 6063 alumi- num alloy profiles is a problem faced by many aluminum production enterprises. The extru- sion experiments were carried out on aluminum inner rib tubes after the extrusion combina- tion cavity was modified carefully. It was found that the die structure was a key factor to in- duce water ripple defect. The residual metal in the cavity was dissected, ground, and colored, and the results show that uneven microstructure has caused disorder of chromatic aberration on the partial surface of the profile. It could be confirmed that zone segregation was the main cause for the water ripple, after samples at different positions of the ingot were analyzed. Wa- ter ripples could be eliminated with the method of the improved casting process, modifica- tion, and low-temperature and low-speed extrusion.