Oxide-dispersion-strengthened (ODS) tungsten based alloys with high performance were synthesized by optimized freeze-drying with PVP and PEG polymer dispersant additives and subsequent low temperature sintering. The pre-freezing principle developed firstly in our work shows that fast cooling rate and polymer dispersant additives contribute to the refinement and uniformity of precursor powders. The optimized freeze-dried W-Y₂O₃ composite powders possess an average grain size of 9 nm, which can be attributed to the steric hindrance provided by polymer dispersants during freeze-drying and voids left by the decomposition of polymer dispersants during calcination. After sintering at low temperature, the W-Y₂O₃ alloys have ultrafine W grain (210 nm) and nano second phase particles (<50 nm) dispersed in W matrix while maintaining a high relative density of 97.8%. These factors mentioned above lead to the microhardness and compressive strength as high as 721 ± 31 HV_0.2, 814 MPa respectively, accompanied by a high total deformation plasticity of above 50%. These results indicate that the optimized freeze-drying and subsequent low temperature sintering is a promising way to fabricate ODS tungsten based alloys with high performance.

通过使用PVP和PEG聚合物分散剂添加剂优化冻干并随后进行低温烧结，合成了高性能的氧化物弥散强化（ODS）钨基合金。在我们的工作中首先开发的预冷冻原理表明，快速的冷却速度和聚合物分散剂添加剂有助于前体粉末的细化和均匀性。优化的冻干WY ₂ O ₃复合粉末的平均粒径为9 nm，这可归因于冻干过程中聚合物分散剂提供的空间位阻以及煅烧过程中聚合物分散剂分解留下的空隙。低温烧结后，WY ₂ O ₃合金具有超细的W晶粒（210 nm）和纳米第二相颗粒（<50 nm）分散在W基体中，同时保持97.8％的高相对密度。上述这些因素导致的显微硬度和抗压强度分别高达721±31 HV _0.2和814 MPa，并具有高于50％的高总变形可塑性。这些结果表明，优化的冷冻干燥和随后的低温烧结是一种制备具有高性能的ODS钨基合金的有前途的方法。