Effect of aging and plastic deformation on the mechanical, magnetic, and thermal properties of cobalt-containing invars

Abstract

The mechanical, magnetic, and thermal properties of water-quenched (from 1150 ° C) alloys, such as ç 36 ä 10 í 3, ç 36 ä 10 ï5í 2, and ç 36 ä 5 í 2, which were strengthened by aging (at 650 ° C) and high-temperature deformation (1100-800 ° C) followed by aging, are studied. The decomposition of a supersaturated solid solution in the Invar alloys under study was shown to increase the strength properties and coercive force but to decrease the plasticity and saturation magnetization. In this case, the aging ambiguously affects thermal expansion coefficient α of the different alloys; the temperature range of invariance decreases. The plastic deformation of Invars was found to increase the ultimate strength, yield strength, and coercive force. The additional aging of deformed materials increases the strength and decreases the plastic properties; among the magnetic parameters, the saturation magnetization exhibits the most adequate correlation with the mechanical properties. The thermal properties (the α coefficient and invariance range) resulting from the complex heat treatment differ slightly from those resulting from the single aging.

Effect of aging on microstructures and properties of Mo-alloyed Fe–36Ni invar alloy

“…Fe-36Ni [5,11], Fe-Ni-Co [12,17,18], Fe-Ni-Ti [19] and Fe-Ni-Mo [10,16], etc. Vinogradov et al [5] reported that the tensile strength of the base Fe-36Ni alloy can be increased up to 912 MPa when its mean grain size was refined to 0.18 μm by the equal-channel angular pressing (ECAP).…”

Strengthening of the Fe-Ni Invar Alloy Through Chromium

“…Fe-Ni binary alloy with a Ni content of ~36 wt.% is known as invar alloy, which shows a very low coefficient of thermal expansion (CTE) of almost zero under 100 °C [1,2,3,4]. Such an anomalous thermal expansion effect of the Fe-36Ni alloy is known as the invar effect [5].…”