Additive manufacturing (AM) creates digitally designed parts by successive addition of material. However, owing to intrinsic thermal cycling, metallic parts produced by AM almost inevitably suffer from spatially dependent heterogeneities in phases and mechanical properties, which may cause unpredictable service failures. Here, we demonstrate a synergistic alloy design approach to overcome this issue in titanium alloys manufactured by laser powder bed fusion. The key to our approach is in-situ alloying of Ti−6Al−4V (in weight per cent) with combined additions of pure titanium powders and iron oxide (Fe₂O₃) nanoparticles. This not only enables in-situ elimination of phase heterogeneity through diluting V concentration whilst introducing small amounts of Fe, but also compensates for the strength loss via oxygen solute strengthening. Our alloys achieve spatially uniform microstructures and mechanical properties which are superior to those of Ti−6Al−4V. This study may help to guide the design of other alloys, which not only overcomes the challenge inherent to the AM processes, but also takes advantage of the alloy design opportunities offered by AM.

增材制造 (AM) 通过连续添加材料来创建数字化设计的零件。然而，由于固有的热循环，由增材制造生产的金属部件几乎不可避免地会在相和机械性能方面存在空间依赖的异质性，这可能会导致不可预测的服务故障。在这里，我们展示了一种协同合金设计方法来克服激光粉末床融合制造的钛合金中的这个问题。我们方法的关键是 Ti-6Al-4V（重量百分比）的原位合金化，同时添加纯钛粉末和氧化铁（Fe ₂ O ₃) 纳米粒子。这不仅可以通过在引入少量 Fe 的同时稀释 V 浓度来原位消除相异质性，而且还可以通过氧溶质强化来补偿强度损失。我们的合金实现了空间均匀的微观结构和机械性能，优于 Ti-6Al-4V。这项研究可能有助于指导其他合金的设计，这不仅克服了增材制造工艺固有的挑战，而且还利用了增材制造提供的合金设计机会。