合金元素对单相渗碳体磁性粉体制备及性能的影响

Effect of Alloying Elements on Single-Phase Cementite Prepared by Mechanical Alloying

通过机械合金化和真空退火热处理的方法制备了单相渗碳体粉末,并结合第一性原理计算,分析了Mn、Cr和Si对合金渗碳体的成相能力及渗碳体磁学性能的影响。结果表明,机械合金化+600℃真空热处理可获得单相渗碳体。Si的加入完全抑制了渗碳体的生成,而加入Mn、Cr对渗碳体生成有促进作用。Cr、Mn合金化的渗碳体的粉末饱和磁化强度及矫顽力较未合金化时纯Fe3C均有所降低,且Cr元素导致的降低幅度更大。合金渗碳体中Cr-C,Mn-C,Fe-C化学键合强度依次减弱,Cr、Mn合金化渗碳体的结构稳定性优于纯Fe3C。

Single-phase cementite powders were prepared by mechanical alloying and vacuum annealing heat treatment methods.Combined with first-principles calculations,the effects of the addition of Mn,Cr,and Si on the phase formation ability and magnetic properties of cementite were analyzed.Results show that single-phase cementite can be obtained by mechanical alloying+600℃vacuum heat treatment.The addition of Si completely inhibits the formation of cementite,while the addition of Mn and Cr promotes the formation of cementite.The saturation magnetization and coercive force of Cr and Mn alloyed cementite are lower than those of pure and unalloyed Fe3C,and the effect of the reduction range caused by the Cr element is greater.The chemical bonding strength of Cr-C,Mn-C and Fe-C in cementite decreases in turn,and the structural stability of Cr-and Mn alloyed cementite is better than that of the pure Fe3C.