The Influence of the Addition of Titanium on the Magnetic Characteristics of New Magnet Alloys “Malcolloy” in the System of Cobalt and Aluminum

Abstract

The present investigators previously found a new magnet alloy “Malcolloy” having a high coercive force in the system of cobalt and aluminum and then conducted studies on the influence of the addition of nickel and molybdenum on their magnetic properties, the highest coercive force obtained being 1600 Oe.
They have now investigated the influence of the addition of titanium on magnetic properties of Co-Al alloys and have found that the coercive force is increased generally by the addition of titanium. Thus, an alloy with the composition of 80.53%Co, 14.84%Al and 4.63%Ti showing a coercive force of 1550 Oe, a residual magnetic flux density of 2850 G, and a maximum energy product of 1.40×10⁶ G·Oe, when tempered at 550°C for 20 hours after water-quenching from 1365°C.
These alloys consist of many elongated-small particles of a ferromagnetic phase dispersed in the matrix of non-magnetic one. Consequently it may be concluded that the in high coercivity is mainly caused by the existence of small particles, each of which is composed of a single magnetic domain.