Near-α Ti alloys are ideal candidates for high-temperature aerospace, automotive and nautical propulsion systems due to their high strength, low density and good corrosion resistance. However, the maximum service temperature of the well-known near-α alloy Ti6242S is limited to about 540 °C. By adding, for example, intermetallic γ-TiAl based alloy particles to Ti6242S powder a significant increase in yield strength up to 650 °C can be achieved by means of spark plasma sintering, along with sufficient room temperature ductility. In this study, investigations on the underlying strengthening mechanisms were carried out. For this purpose, mechanical tests and detailed microstructural characterization were performed.

Spark plasma sintering at 1150 °C of powder blends with 10 m% spherical γ-TiAl based powder (<20 μm) leads to a homogeneous dissolution of the TiAl particles in the matrix material and a refinement of the lamellar microstructure. Due to the formation of ordered intermetallic α₂-Ti₃Al precipitates, which are completely stable up to 670 °C in the newly evolved Ti-8.3Al-1.8Sn-3.7Zr-2.0Mo-0.9Nb-0.08Si alloy (m.%), the creep resistance at 600 °C has been increased significantly. In the B containing variant, it was found that finely distributed titanium borides TiB formed in the Ti6242 matrix and led to an even more pronounced refinement of the microstructure. For B additions of 1 m %, however, the creep resistance at 600 °C is reduced compared to the other alloys, but the strength is increased up to 500 °C.

近αTi合金具有高强度，低密度和良好的耐蚀性，因此是高温航空航天，汽车和航海推进系统的理想选择。但是，众所周知的近α合金Ti6242S的最高使用温度被限制在约540℃。通过在Ti6242S粉末中添加例如基于金属间化合物的γ-TiAl基合金颗粒，可以通过火花等离子体烧结以及足够的室温延展性，使屈服强度显着提高到650°C。在这项研究中，对潜在的加强机制进行了调查。为此，进行了机械测试和详细的微结构表征。

与1 m％球形γ-TiAl基粉末（<20μm）的粉末混合物在1150°C下进行火花等离子体烧结，可将TiAl颗粒均匀溶解在基体材料中，并改善层状微结构。由于有序金属间α的形成₂ -Ti ₃Al析出物，在新发展的Ti-8.3Al-1.8Sn-3.7Zr-2.0Mo-0.9Nb-0.08Si合金中，在高达670°C的温度下完全稳定（m。％），在600°C时的蠕变强度为显着增加。在含B的变体中，发现在Ti6242基体中形成了细分布的硼化钛TiB，并导致了更为显着的微观结构细化。但是，如果添加1 m％的B，与其他合金相比，600°C时的抗蠕变性降低，但强度提高到500°C。