Property Research On NiMnGa Magnetic Functional Materials

Ni-Mn-Ga alloy is the only one that both ferromagnetic and shape memory effect among the Heusler alloy family. In this text, NiMnGaAl alloy and NiMnGaIn alloy were prepared by means of Rapid Solidi-fication technology (copper-mold vacuum suction casting) and shape memory effect and micro-structure were investigated by X-ray diffraction(XRD), Vibrating Sample Magnetometer(VSM), Differential scanning calorimeter, Vickers micro- hardness. We have investigated the related properties effect of change the alloy composition and heat treatment to alloy. The major research efforts as follows:Research on the microstructure and martensitic transformation temperature of Ni54Mn21Ga25-xAlx and Ni54Mn21Ga25-xInx, it can be concluded: doped are not influence the structure of alloys. Under the room temperature condition, alloys are the cube-stucture.Research on the magneto-striction of Ni54Mn21Ga25-xAlx and Ni54Mn21Ga25-xInx, it can be concluded: the magneto-striction of alloys is usually happen in the near martensite transformation temperature. As the Al atom adoped, large magneto-striction of alloys will be quick decrease, and the In atom increase make the magneto-striction decrease quickly.Research on the Vickers hardness of Ni54Mn21Ga25-xAlx and Ni54Mn21Ga25-xInx, We find Al doped make the Vickers hardness down and In doped can not make the Vickers hardness have great change.Research on the saturation magnetization intensity, it can be concluded: Al doped make the saturation magnetization intensity of alloys decline. But In be doped make the saturation magnetization intensity of alloys take the process of rise and down.Through the heat treatment, the stray stress of alloy internal will be eliminated.