Microstructure and Magnetostriction of Galfenol Alloy

The ingots of Fe100-XGaX(X=16、19、21、27)were prepared using vacuum arc melting,and the microstructure and magnetostriction were systematially investigated.It is found that the microstructure of as-cast Fe-Ga alloys exhibits A2 as the main phase,while the crystal lattice constant increase with the Ga content.The volume fraction and distribution of Ga-rich phase directly affect the magnetostriction.Fe81Ga19 alloy has the largest saturation magnetostriction,which can reach up to 93×10-6,however the saturation magnetostriction of Fe79Ga21 alloy is 20×10-6,which result from the precipitation of ordered DO3 phase near(111) and restrict the improvement of magnetostriction.As-cast multi-crystalline Fe84Ga16 alloy present a preferred orientation along the 〈110〉 direction,which deviates from the easy magnetization orientation of 〈100〉,thus has a lower magnetostriction..