The hardness and strength of copper wire depends on the degree of hardening: the more the wire is deformed during cold drawing, the harder/stronger it is. Although the hardness of copper wire for electrical wiring is standardized, it may vary slightly from batch to batch and plant to plant. Thus, the point is not the age of the wire, but small differences in its manufacture.

Thank you .Dr. Vadim VErlotski

for your interest in the subject, but I mean to hint about whether the electrical hardness of wires is affected by high electric currents over a long time, in terms of deformation of the structural material particles of the wire. Even if it is under the work conditions imposed by the company, and to stay away from all affecting conditions such as exposure to the sun. Because I noticed that there are distortions in the composition of the material. Thank you for your cooperation

Please claify what you mean by "electrical hardness"- is it mechanical hardness or electronic conductivity you are talking about?

Al and Cu wires can undergo natural annealing at room temperature (especially Al) for months or years, so they can soften with time. Also there are issues with oxide formation under insulating coating of wires, and obviously ammonia does harm to copper wire by stress corrosion cracking. "Less mechanical properties" is also not clear. If you mean less mechanical strength, then in is due to annealing. But for less ductility or electronic conductivity, I do think corrosion can be blamed.

Sorry, I mean the mechanical hardness resulting from the high electric currents.

The speed of the electric charges released as a result of the high voltage, which in turn will generate high electric fields between the particles of matter. The electrons shoot at a high speed colliding with each other to generate an electric current of the amount of that applied voltage and in relation to the resistance of that wire.

But I think that as a result of these massive collisions, sometimes charged particles are generated as a result of the high electric field and potential difference and these collisions, not just electrons. These charges work to deform the surface particles of the material, with a long time. So I try to study the effect of these particles and their quality. Thank you

Thank of Dr. Sumit Bhowmick. For your answer

Well, first of all, I am not a Doctorate. Secondly, As for your further question, electromigration and "force from electron wind" in DC wires can affect hardness and ductility, either by directionalizing, hastening annealing, or causing precipitation and chemical change of minor phases at grain boundaries than may cause brittleness ,somwhat like ionizing radiation, but electrons in solid wire do not have enough directed kinetic energy to knock out ions (calculate eV, 1/2 mv^2 and kT to have appreciation of the facts!) but can do the slow job of moving by electromigration, for example H, O, P in copper wire or Si, Fe etc in aluminium wire, although in minuscule amount.

Thank you very much for this concept.

This small electricals migration that you are talking about its. will causing, after over long periods of time, of change the hardness of the electrical wires. Therefore, I study about this object, on the condition that the wires are far from natural conditions influence. Knowing that I did not ask a second question, but an explanation of the same question. therefore, I search about researcher worked in this subject.