Association of Metallurgical Engineers of Serbia AMES Scientific paper UDC: 669.35.018.52-174 HIGH ELECTRICAL CONDUCTIVITY Cu-BASED ALLOYS. PART I

Effect of thermomechanical treatment (TMT), i.e. prior plastic deformation, time and temperature of aging on microstructure, hardness, electrical conductivity and thermal stability of Cu-0.4%Cr-0.08%Zr and Cu-0.4%Cr-0.08%Zr-0.05%Mg (in wt.%) alloys has been investigated. Both alloys behave in the similar manner under TMT. The maximum value of hardness was within the range of 1520 to 1630 MPa after cold rolling for 50 and 80 % followed by aging at 425 oC for 2h. The maximum of electrical conductivity which is between 89 and 92 % IACS appears at 480 oC. These properties together with high thermal stability of both alloys (around 520 oC) are quite satisfactory compared to properties of commercial Cu-based alloys. Considering practical application Cu-0.4%Cr-0.08%Zr-0.05%Mg alloy might be regarded as very interesting because the TMT avoids high temperature solution annealing and quenching, without reducing the hardness and electrical conductivity. Key words: thermal stability, recrystallization, hardness, electrical conductivity, spot welding electrode