Abstract: The invention refers to batch casting, semi-continuous casting or continuous casting and rolling of copper, providing the addition of lead or refining the melt copper or the melt microalloyed copper to a lead content equal to or higher than 200 weight ppm. This minimizes the number of pores and defects, decreasing the number of incidences or breaks during casting and in service. However, it does not reduce the electrical conductivity. The addition of lead allows the cast and roll of copper microalloyed with elements such as S, Se, As, Sb, Bi, Sn, Zn, Ni, Fe, Ag and Te, in concentrations of the order of tens of weight ppm. The copper microalloys manufactured in this way have annealing temperatures and strain strengths higher than those obtained from the equivalent tough-pitch copper or the equivalent microalloyed copper with lead content lower than 15-20 weight ppm.

Abstract: We provide a new copper microalloy with high-conductivity, excellent heat resistance and high strain strength, which can be obtained by conventional continuous or semi-continuous casting, which essentially consists of at least one element selected from the following list:______________________________________ 5-800 mg/Kg Pb (lead) 10-100 mg/Kg Sb (antimony) 5-1000 mg/Kg Ag (silver) 5-700 mg/Kg Sn (tin) 1-25 mg/Kg Cd (cadmium) 1-30 mg/Kg Bi (bismuth) 20-500 mg/Kg Zn (zinc) 10-400 mg/Kg Fe (iron) 15-500 mg/Kg Ni (nickel) 1-15 mg/Kg S (sulfur) ______________________________________in all cases, with 20-500 mg/Kg O (oxygen). The alloy is suitable for all the applications that require an electrical conductivity similar to that of pure copper, but with a better heat resistance, better mechanical properties and lower standard deviation values in strain strength.