Defect Formation during the Manufacture of Copper Alloy Tubes

The causes promoting the formation of defects on the internal surface of two different copper alloys subjected to cold rolling to fabricate seamless copper tubes are described. Defects characterized by oxide formation and delaminated material were found in various zones along the length of the tubes, leading to crack formation. It was found that the alloy that presented severe failure included a considerable amount of Cu 2 O particles. These particles were responsible for incorrect material flow during manufacturing and acted as crack initiation sites.