Application of lasers to cutting copper and copper alloys

Abstract

Copper and Cu alloys are considered difficult materials to cut using lasers, because of their high reflectivity and thermal conductivity. This work was performed to examine the potential and limitations of laser cutting these alloys. A series of laser cutting experiments was carried out on Cu, 70–30 brass, and 90–10 Cu–Ni strip using Nd–YAG and CO2 lasers of various power capabilities. A higher degree of process efficiency and easier cut initiation were exhibited by Nd-YAG lasers, because of the lower reflectivity of Cu to Nd–YAG laser radiation. It was possible to obtain good quality cuts with the lasers used, although some dross remained beneath the cut, particularly with the higher power laser. The cutting process had no adverse effects on the metallurgy of the strip and no oxidation was observed adjacent to the cut. No dezincification was observed for the brass samples and recrystallisation did not occur in heavily worked materials.MST/892