Preparing high relative density γ-TiAl alloy by pressure-less sintering at low-cost has always been a challenge. Therefore, a new kind of non-spherical pre-alloyed TiAl powder was prepared by the reaction of TiH₂ powder and Al powder at 800 °C to fabricate high-density Ti-48Al alloy via pressure-less sintering. The oxygen content was controlled to below 1800 ppm by using coarse Al powder (~120 μm). The sintered densities ranged from 92.1% to 97.5% with sintering temperature varying from 1300 °C to 1450 °C. The microstructure of the sintered compact was greatly influenced by the sintering temperature. The as-sintered samples had a near-γ structure at 1350 °C, a duplex structure at 1400 °C, and a nearly lamellar structure at 1450 °C. To achieve full densification, non-capsule hot isostatic pressing was performed on the 1350 °C and 1400 °C sintered samples. As a result, high compressive strengths of 2241 MPa and 1931MPa were obtained, which were higher than the existing Ti-48Al alloys.

中文翻译：

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不规则预合金粉末制备高相对密度γ-TiAl合金的组织和力学性能

通过低成本无压烧结来制备高相对密度的γ-TiAl合金一直是一个挑战。因此，通过TiH ₂的反应制备了一种新型的非球形预合金化TiAl粉末。粉末和Al粉在800°C的条件下通过无压烧结制造高密度Ti-48Al合金。通过使用粗大的Al粉（〜120μm）将氧气含量控制在1800 ppm以下。烧结密度在92.1％至97.5％的范围内，烧结温度在1300°C至1450°C之间变化。烧结体的微观结构受烧结温度的影响很大。烧结后的样品在1350°C时具有近γ结构，在1400°C时具有双相结构，在1450°C时具有近层状结构。为了实现完全致密化，对1350°C和1400°C的烧结样品进行了非胶囊热等静压。结果，获得了2241 MPa和1931 MPa的高抗压强度，高于现有的Ti-48Al合金。