The C15 Laves phase with composition Tb0.2Pr0.8（Fe0.4Co0.6）1.93 was synthesized by mechanical alloying （MA） and subsequent annealing process. The structure and magnetic properties of Tb0.2Pr0.8（Fe0.4Co0.6）1.93 were investigated by means of X-ray diffraction （XRD）, a vibrating sample magnetometer, and a standard strain technique. The effect of annealing on the structure and magnetic properties was studied. The analysis of XRD shows that the high Pr-content Tb0.2Pr0.8（Fe0.4Co0.6）1.93 alloy with the single phase of MgCu2-type structure can be successfully synthesized by MA method. The sample annealed at 450℃ is found to have a coercivity of 196 kA/m at room temperature. An epoxy/Tb0.2Pr0.8（Fe0.4Co0.6）1.93 composite was produced by a cold isostatic pressing technique. A large magnetostriction of 400 ppm, at an applied magnetic field of 800 kA/m, was found for the composite. The epoxy-bonded Tb0.2Pr0.8（Fe0.4Co0.6）1.93 composite combines a high magnetostriction with a significant coercivitv, which is a oromising magnetostrictive material.
Mechanical alloying (MA) and subsequent solid sintering process was used to prepare the Nd-containing magnetostrictive Tb0.4Nd0.6(Fe0.8Co0.2)1.90 alloy. The structure, thermal stability and phase transformation were investigated as functions of composition, milling process and annealing temperature. An amorphous phase was formed by high-energy ball milling for 5 h with the ball-to-powder weight ratio of 20:1, which crystallized into MgCu2-type and PuNi3-type crystalline structure with different annealing temperatures. The magnetoelastic properties were investigated by means of a standard strain technique. The high Nd-content (Tb,Nd)(Fe,Co)2 Laves phase for the composition Tb0.4Nd0.6(Fe0.8Co0.2)1.90 was synthesized by MA process plus annealing at 500 ℃ for 30 min.
Liu JinjunWang RongYin HongyunLiu XincaiSi PingzhanDu Juan
