Copper vs Pure Nickel's Amperage/mm^2

Can someone smarter than me confirm this please? Thank you.

I was looking at this graph and decided to do an amperage/mm^2.

As you can see, the pure nickel strip is consistent with 14aa/mm^2.

Meanwhile copper, decreases as cross-section increases.

I basically asked ChatGPT and this is what it said.

Can someone confirm?

Thank you.



Pure Nickel:

  • Resistivity: Nickel has a higher and relatively stable resistivity compared to copper. This makes its current-carrying capacity more linear with cross-sectional area because resistance dominates the heating effect, leading to a proportional relationship.
  • Thermal and Electrical Limits: Nickel’s material properties make it more uniform in performance across sizes. Its higher resistivity reduces current density, which inherently stabilizes Amperage/mm2\text{Amperage/mm}^2Amperage/mm2.

Copper:

  • Resistivity: Copper has much lower resistivity, so it can carry more current for a given cross-sectional area. However, as the cross section increases, skin effect, heat dissipation, and mechanical factors (like heat-induced stress or installation constraints) can limit effective current capacity. These practical issues lead to a nonlinear relationship for Amperage/mm2\text{Amperage/mm}^2Amperage/mm2.
  • Thermal Limits: In smaller wires, copper can handle higher current densities because heat can dissipate quickly. In larger wires, overheating becomes a concern, reducing Amperage/mm2\text{Amperage/mm}^2Amperage/mm2 as the cross-section increases.
  • Standardization: Copper ratings often follow practical safety standards (e.g., insulation and cooling considerations) rather than purely physical limits.

In summary, pure nickel’s consistent Amperage/mm2\text{Amperage/mm}^2Amperage/mm2 is due to its resistivity and uniform thermal behavior, while copper’s variability comes from its superior conductivity and the influence of external practical constraints as the cross section grows.