The effects of W on the microstructure and tensile properties of two high Mn-containing β-γ TiAl alloys (nominal composition is Ti–42Al–5Mn and Ti–42Al–5Mn-0.8 W (at.%)) prepared by vacuum induction melting and conventional forging process were systematically investigated. The results showed that there were coarse columnar lamellar colonies in the as-cast W-free alloy, but in the W-added alloy, the microstructure was relatively uniform without the presence of coarse columnar lamellar colony. After forging, the two alloys were all nearly lamellar structure. With W addition, the lamellae size was reduced and the volume fraction of lamellar colonies was slightly decreased whereas the contents of β_o and γ phases around the lamellar colony were increased. The partitioning behavior of W has also been investigated which was in the order of β_o>α₂>γ in Ti–42Al–5Mn-0.8 W. The research results also proved that W addition had little effect on the distribution behavior of Ti and Al in γ and α₂, whereas it has pronounced impact on that of Mn, Ti and Al in β_o. Under 800 °C ageing conditions, a large amount of granular Laves (Ti(Al,Mn)₂) phase precipitated from β_o phase in the as-forged W-free alloy, which resulted in the brittle fracture at room temperature. On the contrary, the microstructure and tensile properties of the W-added alloy remain relatively stable with only a small amount of Laves phase observed, most of the β_o phase remained unchanged in the ageing samples. The Laves phase suppressed in W contained alloy are mainly due to the influences of W on the distribution of Mn in the β_o, and the diffusion and enrichment behavior of Mn during ageing.

W对真空感应熔炼制备的两种高Mn含量β-γ TiAl合金（标称成分为Ti-42Al-5Mn和Ti-42Al-5Mn-0.8 W（at.%））显微组织和拉伸性能的影响并对常规锻造工艺进行了系统研究。结果表明，铸态无W合金中存在粗大的柱状层状菌落，而在添加W的合金中，显微组织相对均匀，没有出现粗大的柱状层状菌落。锻造后两种合金均呈近层状结构。随着 W 的加入，片层尺寸减小，片层菌落的体积分数略有下降，而 β _o的含量层状菌落周围的γ相增加。还研究了 W在 Ti-42Al-5Mn-0.8 W 中按 β _o >α ₂ >γ的顺序分配的行为。研究结果还证明 W 添加对 Ti 和γ和α _{2 中的}Al ，而β _o中对Mn、Ti和Al的影响显着。在 800 ℃时效条件下，β _o析出大量粒状 Laves (Ti(Al,Mn) ₂ ) 相锻造态无钨合金中的相，导致室温脆性断裂。相反，添加 W 合金的显微组织和拉伸性能保持相对稳定，仅观察到少量 Laves 相，大部分 β _o相在时效样品中保持不变。含W合金中Laves相的抑制主要是由于W对Mn在β _{o 中}的分布以及时效过程中Mn的扩散和富集行为的影响。