New Fe-Cr-Mo glass-sealable semi-hard magnet alloys for remanent reed contacts

New, cobalt-free, glass-sealable, semi-hard magnet alloys based on an Fe-Cr-Mo system have been developed as a potential substitution of Co-Fe base alloys such as Type 27 Remendur (49Co-48Fe-3V) in remanent reed contact switch applications. Fe-11\sim15Cr-4\sim5Mo (wt.%) alloys can be processed to exhibit desirable magnetic properties of Br\sim14-15 KG, Br/Bs∼0.9 and Hc \sim25-35 Oe. These alloys maintain a sufficient ductility and formability even after a severe wire drawing. Magnetic hardening of the deformed wire is achieved by subsequent low temperature aging heat treatment. The new alloys are easy to process, exhibit a significantly lower value of λs than Remendur, and are glass sealable with the same type of glass used for Remendur. The feasibility of substitution for the high-cobalt and expensive Remendur in remanent reed contact switches has been demonstrated in the laboratory.