Abstract

The W-1%Y₂O₃-0.5%Ti composite fabricated by the spark plasma sintering method has been tested on the EMS-60 facility using 0 to 600 MW/m² with pulse duration of 5 ms for single and 100 cycles. It is shown that the cracking threshold under single pulse of the W-1%Y₂O₃-0.5%Ti is close to 300 MW/m², which exceeds that of pure tungsten (~200 MW/m²). Moreover, the crack morphology is different than that of pure W under the same heat load condition. These experimental data illustrate that the addition of dispersed oxides and alloying elements can, to some extent, ameliorate high heat load behaviors. Meanwhile, it should be noted that the melting and volatility of the second phase if the heat flux exceeds 400 MW/m² for a single pulse will narrow the operation range of the composite. And, the severe damages of crack and matrix melting under fatigue shocks illustrate that the composite still needs further efforts to be improved by the optimization of fabrication processing.

摘要

通过火花等离子体烧结法制备的W-1％Y ₂ O ₃ -0.5％Ti复合材料已在EMS-60设施上以0至600 MW / m ²的频率进行了测试，脉冲持续时间为5 ms，单周期和100周期。结果表明，W-1％Y ₂ O ₃ -0.5％Ti单脉冲下的开裂阈值接近300 MW / m ²，超过了纯钨的开裂阈值（〜200 MW / m ²）。此外，在相同的热负荷条件下，裂纹形态不同于纯钨。这些实验数据表明，添加分散的氧化物和合金元素可以在一定程度上改善高热负荷行为。同时，应当注意，如果对于单个脉冲热通量超过400MW / m ²，则第二相的熔融和挥发性将使复合物的操作范围变窄。并且，疲劳冲击下裂纹和基体熔化的严重破坏表明，复合材料仍然需要通过优化制造工艺来进一步改进。