High Strength Copper-Silver Conductors for Magnets

Published November 14, 2024

Microscopy images on longitudinal x-section

Because of such desirable properties as high mechanical strength and electrical conductivity, Cu–Ag nano-structured sheets are used, not only in high field DC magnets, but also in the insert for our 45 T hybrid magnet. Because the property anisotropy of these sheets must be considered in these applications, we have now further studied this anisotropic behavior, evaluated the strain-hardening or strain-softening capacity of these sheets, and correlated this capacity with their microstructure.

What did scientists discover?

MagLab researchers studied the strain-hardening behavior of high-strength copper silver sheets by comparing overall and local stress-strain curves. They found that while both longitudinal and transverse samples showed overall softening, regions with highly strained slip bands displayed significant local strain-hardening in transverse samples and moderate strain-softening in longitudinal ones. This difference in localized plasticity caused the conductors to show overall anisotropic behavior.

Why is this important?

To maintain our high-field magnets, we need a constant supply of conductors that must pass strict quality checks. This work also has impact beyond high field magnets since Cu-Ag conductors can be used in advanced electronics, electrical and power grid industries, and aerospace and defence . Research on Cu-Ag conductors by Pimentel, Wu, Xin, and others was recognized at the 2024 Microscopy and Microanalyses conference, attended by 2,341 researchers. This work was one of only 15 to receive the "2024 M&M Student & Postdoctoral Scholar Award."

Who did the research?

R. Niu ¹, V. Toplosky ¹, H.L.S. Matos Pimentel ¹, Y. Xin ¹, J. Toth ¹, and K. Han¹

¹Florida State University, National MagLab

Why did they need the MagLab?

The MagLab has unique facilities for characterizing materials, from the atomic level to full conductor size. It offers advanced mechanical testing to analyze strain in two dimensions and high-resolution microscopes to study material deformation. The lab also benefits from the expertise of its metallurgists and materials scientists.