High Strength and High Electrical Conductivity Cu-Ti Alloy Wires Fabricated by Aging and Severe Drawing

We designed an optimal procedure to prepare Cu-Ti alloy wires with an excellent combination of strength and electrical conductivity, by drawing conventional peak-aged alloys as well as over-aged ones. When drawing the peak-aged alloy, which exhibited the maximum hardness after aging and a low electrical conductivity, the strength of the wires increased rapidly in the initial stage of drawing but then saturated on further drawing. On the contrary, when drawing the over-aged alloy of inferior hardness but superior electrical conductivity, the strength increased steadily through drawing and eventually exceeded the value of the wires drawn from the peak-aged alloy. Also, the electrical conductivity of the wires drawn from the over-aged alloy was always much greater than that from the peak-aged alloy. Thus, we demonstrated that the procedure of over-aging and then drawing severely is able to enhance both the strength and the electrical conductivity for the Cu-Ti alloys, rather than the conventional peak-aging and drawing process. Noted that the performance of the wires drawn from the over-aged alloy is comparable with that of commercial Cu-Be wires, which are considered to possess the combination of greatest strength and conductivity in Cu-based alloys.