在Ｎ＿２气氛中，用蒸发冷凝法，制备了不同平均粒径（１２～１００ｎｍ）的Ｆｅ－２９ｗｔ％Ｎｉ合金超细微粒样品。它们是马氏体ａ’（ｂｃｃ）和奥氏体γ（ｆｃｃ）的混合体。而且，马氏体体积分数随样品平均粒径减小而明显增加。实验表明，手工研磨，导致马氏体体积分数和比磁化强度显著增大。平均粒径越大，这种影响越大。 Under N 2 atmosphere, Fe-29wt% Ni alloy ultrafine particles with different average particle sizes (12 ~ 100nm) were prepared by evaporation condensation method. They are a mixture of martensite a ’(bcc) and austenite γ (fcc). Moreover, the volume fraction of martensite increases with decreasing average particle size of the sample. Experiments show that manual grinding, resulting in martensite volume fraction and magnetization significantly increased. The larger the average particle size, the greater this effect.