论文标题
衰老对含W的虹膜 - 虹膜合金特性的影响
Effect of ageing on the properties of the W-containing IRIS-TiAl alloy
论文作者
论文摘要
研究了800 $^\ circ $ c对虹膜合金属性的影响（ti $ _ {49.9} $ al $ _ {48} $ w $ _2 $ _2 $ _2 $ b $ _ {0.1} $）。这种通过火花等离子体烧结（SPS）致密的合金的初始微观结构主要由层状菌落组成，这些层菌落被$γ$晶粒所包围。通过相关的机械测试测量了由于这种老化处理而导致的合金强度和蠕变抗性的演变。通过扫描和透射电子显微镜以及X射线衍射研究了微观结构的变化。主要的结构演变由层状区域的收缩和$β_0$相位的沉淀组成，并伴随着中等繁殖的钨，$α_2$ lamellar宽度的降低。但是，这些演变相对有限，并且发现微结构稳定性主要来自钨的低扩散率。相反，测量了这种老化治疗对机械性能，在房间和高温下的中等影响。根据微观结构的演变和变形机制在各种概念下在不同的温度下激活，对这种实验结果进行解释和讨论。
The effects of ageing at 800 $^\circ$C on the properties of the IRIS alloy (Ti$_{49.9}$Al$_{48}$W$_2$B$_{0.1}$) are studied. The initial microstructure of this alloy densified by Spark Plasma Sintering (SPS) is mainly composed of lamellar colonies which are surrounded by $γ$ grains. The evolutions of the alloy strength and creep resistance resulting from this ageing treatment are measured by the related mechanical tests. The microstructural changes are investigated by scanning and transmission electron microscopies and by X-ray diffraction. The main structural evolutions consist in a shrinkage of the lamellar areas and in a precipitation of $β_0$ phase, which is accompanied by a moderate segregation of tungsten and a decrease of the $α_2$ lamellar width. However, these evolutions are relatively limited and the microstructural stability is found to result mainly from the low diffusivity of tungsten. Conversely, a moderate effect of this ageing treatment on mechanical properties, at room and high temperatures, is measured. Such experimental results are interpreted and discussed in terms of the microstructural evolutions and of the deformation mechanisms which are activated at different temperatures under various solicitations.
