Zhang Jingqi, Liu Yingang, Sha Gang, Jin Shenbao, Hou Ziyong, Bayat Mohamad, Yang Nan, Tan Qiyang, Yin Yu, Liu Shiyang, Hattel Jesper Henri, Dargusch Matthew, Huang Xiaoxu, Zhang Ming-Xing
School of Mechanical and Mining Engineering, The University of Queensland, St. Lucia, Brisbane, Australia.
Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science a nd Technology, Nanjing, China.
Nat Commun. 2022 Aug 9;13(1):4660. doi: 10.1038/s41467-022-32446-2.
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 (FeO) 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）通过逐层添加材料来制造数字化设计的零件。然而，由于固有的热循环，增材制造生产的金属零件几乎不可避免地会在相和机械性能方面存在空间依赖性的不均匀性，这可能导致不可预测的服役失效。在此，我们展示了一种协同合金设计方法，以克服激光粉末床熔融制造的钛合金中的这一问题。我们方法的关键在于对Ti-6Al-4V（重量百分比）进行原位合金化，同时添加纯钛粉末和氧化铁（FeO）纳米颗粒。这不仅能够通过稀释钒浓度并引入少量铁来原位消除相不均匀性，还能通过氧溶质强化来弥补强度损失。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，不仅克服了增材制造工艺固有的挑战，还利用了增材制造提供的合金设计机会。
