Effect of Secondary Aging of Copper-Chromium Alloys to Electrical Conductivity

Abstract

Copper-chromium alloys are the most important spot-welding tips and disks; it is also used where high strength together with electrical conductivity is required. Electrical conductivity is also important for optimum energy consumption. It is obvious that if highly conductive materials are used, we need low electric current where today energy is a very precious thing. In our study due to the industrial requirement of highly durable and more consistent parts needs, secondary aging was used to obtain more efficient materials. Electrical conductivity is a must, therefore the copper chromium alloys were observed for their resistances for various processing conditions, like as cast, aged, and secondarily aged. The electrical resistance measurements for all conditions were done and compared. The aging heat treatment was done at 650 oC for 4 hours. Secondary aging heat treatment was done at 400 oC for 2, 4, and 6 hours. The lowest specific electrical resistivity was obtained from secondary aged at 400 oC for 2 hours as 0.0074 mΩ mm2/mm. The resistance of as-cast copper-chromium alloy was measured as 0.078 mΩ mm2/mm which is almost ten-fold resistive than secondarily aged sample therefore it can be said that the secondary aging heat treatment was found to have a favorable electrical conductance.