The Mechanical Properties During Thermomechanical Treatment of an Al-Cu-Mg-Si Alloy Intended for Zippers.

Abstract

The objective of this project has been to find a suitable thermomechanical treatment for an Al- Cu-Mg-Si alloy. The aluminium alloy is to be used in zippers, produced by YKK, for jeans. The composition of the alloy is 1,25 wt% Cu, 1,03 wt% Mg and 0,37 wt% Si. The goal for the thermomechanical treatment was to reach a hardness of 150 HV and an elongation of five percent (or more) at fracture. The material was in all cases cold rolled to 20% of initial thickness. The different deformation and artificial conditions were tested with hardness tests, tensile tests, differential scanning calorimetry and some samples were also studied in TEM. Two conditions gave an average hardness of 147 HV and 148 HV, and an elongation of more than five percent on all samples. Since the difference between these two cases was so little, the artificial aging at 170ºC seems to be most suitable for production, because of the shorter aging time.