The microstructure, mechanical properties (at 25 °C, 1000 °C, 1200 °C, 1400 °C and 1600 °C) and oxidation behavior (at 1600 °C) of a binary Hf-27%Ta alloy and three ternary alloys, Hf-21%Mo-21%Ta, Hf-21%Nb-21%Ta and Hf-21%Ta-21%W (compositions are in atomic percent) are reported. The alloys were produced by vacuum arc melting, hot isostatically pressed under a high-purity argon pressure of 207 MPa at 1400 °C for 3 h and slow cooled to room temperature. The Hf-27Ta alloy had a microstructure consisting of coarse primary HCP particles and a monotectoidally transformed matrix consisting of a nano-lamellar mixture of the Ta-rich BCC and Hf-rich HCP phases. The Hf-21Mo-21Ta alloy consisted of a BCC matrix phase and HCP precipitates. Hf-21Nb-21Ta had a microstructure consisting of a BCC matrix phase, spherical nano-precipitates inside the matrix grains and two-phase BCC lamellar regions at grain boundaries, with no HCP phase detected. The Hf-21Ta-21W alloy had a three-phase structure consisting of a Hf-rich HCP matrix, W-rich cubic Laves phase and monotectoidally transformed regions consisting of nano-lamellae of Ta-rich BCC and Hf-rich HCP phases. The alloys had limited ductility at room temperature but they all were well workable at T ≥ 1000 °C. Among the studied alloys, the binary Hf-27Ta was the strongest at room temperature and the Hf-21Mo-21Ta was the strongest at high temperatures. The oxidation kinetics of Hf-27Ta, Hf-21Mo-21Ta and Hf-21 W-21Ta were similar, with 30–40 mg/cm² mass gain per 1 h holding at 1600 °C. The Hf-21Nb-21Ta alloy exhibited much higher (~230 mg/cm²/h) mass gains at 1600 °C. The ternary alloys all showed evidence of the formation of gaseous and/or liquid species in the oxide scales.

二元Hf-27％Ta合金和三种三元合金的微观结构，力学性能（在25°C，1000°C，1200°C，1400°C和1600°C时）和氧化行为（在1600°C下），报道了Hf-21％Mo-21％Ta，Hf-21％Nb-21％Ta和Hf-21％Ta-21％W（组成以原子百分比计）。通过真空电弧熔化，在207 MPa的高纯氩气压力下在1400°C下热等静压3 h并缓慢冷却至室温来生产合金。Hf-27Ta合金的微观结构由粗HCP初级粒子和由富含Ta的BCC和富含Hf的HCP相的纳米片状混合物组成的单相转变基质组成。Hf-21Mo-21Ta合金由BCC基体相和HCP沉淀组成。Hf-21Nb-21Ta的微观结构由BCC基质相组成，球形纳米沉淀在基体晶粒内部和晶界处的两相BCC层状区域内，未检测到HCP相。Hf-21Ta-21W合金具有由富Hf的HCP基体，富W的立方Laves相和由富Ta的BCC纳米片和富Hf的HCP相组成的单相变区组成的三相结构。合金在室温下的延展性有限，但是它们在室温下都可以很好地加工Ť  ≥1000℃。在研究的合金中，二元Hf-27Ta在室温下最强，Hf-21Mo-21Ta在高温下最强。Hf-27Ta，Hf-21Mo-21Ta和Hf-21 W-21Ta的氧化动力学相似，在1600°C的条件下，每1 h的质量增加量为30-40 mg / cm ²。Hf-21Nb-21Ta合金在1600°C时表现出更高的质量增加（〜230 mg / cm ² / h）。三元合金都显示出在氧化皮中形成气态和/或液态物质的证据。