Popis: |
Magnet insulation materials in many Next‐Step Option fusion research devices will be subjected to high shear stresses at both cryogenic and elevated temperatures. The low shear strength and poor adhesion of the insulation to copper conductors can be limiting design factors in these systems. While cyanate ester resins have been shown to provide the necessary electrical and mechanical properties for fusion magnet insulation applications, the adhesion of the resin to copper at temperatures ranging from 77 to 373 K is a critical aspect of long‐term operational performance. This work compares the shear strengths of copper/cyanate‐ester‐insulation interfaces prepared using various copper surface treatments, including grit blasting, alkaline cleaners, oxidizers, and primers. The shear strengths of the copper/cyanate‐ester‐insulation interface were measured using a novel specimen design in which thin copper foils were treated and embedded in laminate structures. Short‐beam‐shear tests were conducted at 76, 293, a... |