High-strength magnetically hard Fe-Cr-Co-Based alloys with reduced content of chromium and cobalt

Abstract

Structure and magnetic and mechanical properties of precipitation hardening Fe-Cr-Co-W-Ga alloys with reduced Cr and Co contents have been studied. The compositions studied go beyond the limits of the miscibility gap in the phase diagram for conventional Fe-Cr-Co alloys. It has been established that after cold plastic deformation and low temperature annealing the alloys are characterized by high values of mechanical and magnetic characteristics, which are significantly higher than those of known analogs. It is demonstrated that the treatment suggested leads to the decomposition of homogeneous solid solution based on α Fe with the precipitation of disperse particles of a tungsten rich phase, which promotes strengthening of alloys.

The role of plastic deformation in the creation of high strength in hard magnetic alloys Fe-Cr-Co-W-Ga

“…High strength properties are also characteristic of the Fe-Cr-Co-W-Ga alloys, in which Cr and Co contents are lower than the boundary of the miscibility gap for the α solid solution (12-20% Cr and 12-14% Co) [4]. In these alloys in the course of postdefor mationl low temperature annealing there occurs a decomposition of the homogeneous solid solution with the precipitation of disperse particles of the η' phase.…”

Experimental Study on the Grinding of an Fe-Cr-Co Permanent Magnet Alloy under a Small Cutting Depth

“…In recent years, with the development of science and technology, the machining precision of magnetic materials has become more and more important. Most investigations have mainly been focused on the effect of various factors on the magnetic properties and structure of Fe-Cr-Co permanent magnet alloys, including heat treatment processes [11][12][13], temperature and mechanical treatment [14][15][16][17][18] and changed alloy elements [19][20][21][22]. For example, Wu Xin et al found that alloy treated with solid solution and thermal magnetic and multi-step aging exhibited better magnetic properties when saline water was used as the solution coolant [11], while Liu Yan et al found that Fe-Cr-Co permanent magnets under the action of low-frequency vibration force, there would be a regular demagnetization increase phenomenon, but vibration to a certain time, the magnetic properties basically tend to constant.…”

“…[15]. Furthermore, E. V. Belozerov et al reported hard magnetic (Fe-22% Cr-15% Co) alloys with high strength and plasticity, and sufficiently high magnetic properties were obtained by the doping of alloys with tungsten and gallium [20,21]. However, few investigations on the effect of grinding on the performance of Fe-Cr-Co permanent magnetic alloys have been reported.…”

Effect of Initial Composition on the Phase Composition of High-Strength Fe-Cr-Co-Based Magnetic Materials

“…An essential contribution was made by the Mossbauer method which helped to pick out different regions constituting the structure and estimate their compositions and volume fractions [2]. Further studies were aimed at searching a way of gaining the required properties on alloys with lowered concentrations of Cr and Co, and compositions with improved mechanical properties were obtained, though with a somewhat lowered coercivity [3]. However, the effect of the initial composition on the processes taking place in the structure of these alloys is still unclear and needs special research.…”