【摘要】 采用电弧熔炼并直接在冷坩埚中凝固,得到了具有单向凝固特征的TiAl合金纽扣锭,以此研究了合金元素W对单向凝固组织的影响。结果表明,W对TiAl合金单向凝固的枝晶组织有细化作用,当W含量为2.5%时,可以将凝固组织的晶粒宽度减小到200μm,二次枝晶间距减小到50μm。随着W含量的增加,先凝固形成的β相晶粒内部出现网络分布的富W相,并最终转变为B2相。Ti-46Al合金中加入W元素后,片层团尺寸及片层厚度减小。更多还原

【Abstract】 Effects of W on the unidirectional solidification structures of TiAl based alloy which was prepared by solidifying in a cold crucible after non-consumable arc melting were observed.The results indicate that dendrite in the TiAl based alloy can be greatly refined with W additon,in which grain size can be decreased to approximately 50μm with 2% W addition.With increasing in W addition,net-like W-rich phase appear in the primary β phase,and it is transformed into B2 phase.In addition,lamellar colony size can be decreased in the Ti-46Al alloy with W addition.更多还原