Papers by Author: Irina I. Kositsyna

Abstract: A new way of considerable improvement of properties of soft magnetic alloys is offered. This way actually consists in the use of an ion beam treatment in the manufacturing technology for these alloys. Depending on the properties, which need improvement (magnetic softness or magnetostriction), the ion beam treatment is performed before or after a thermomagnetic treatment.

Abstract: The methods of electron microscopy, resistometry and magnetometry are used to study ten (36-38)Co - (32-36)Ni - (27-30)Al (at. %) alloys. Cast coarse-crystalline and microcrystalline alloys made by melt spinning in a helium atmosphere are considered. It is shown that the martensite start temperature Ms becomes 30-50°C lower as grains are refined to 1 m m. Replacement of 1 at. % cobalt by nickel and 1 at. % aluminum by nickel makes the temperature interval of the В2«L10 martensite transformation (30-60)°C and (100-110)°C higher respectively. The martensite transformation hysteresis is about 100 degrees. The melt-spun Co38Ni34Al28 alloy with the transformation temperatures Мs = 31°С, Мf = –34°С, Аs = –6°С, Аf = 70°С and Тс = 98°С is a material possessing the magnetically controlled shape memory effect.

Abstract: A new concept is suggested that serves to explain the effects of thermomagnetic treatment. Its validity is proved via measurements of magnetic properties and electron microscopy examination of structure of soft magnetic materials after different treatments. This concept allows one to consciously choose the treatment mode aiming on improvement of magnetic properties of alloys.