Influences of hot-isostatic-pressing temperature on microstructure, tensile properties and tensile fracture mode of Inconel 718 powder compact
Influences of hot-isostatic-pressing temperature on microstructure, tensile properties and tensile fracture mode of Inconel 718 powder compact
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DOI：
10.1016/j.msea.2014.01.095
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发表时间：
2014-04-02
期刊：
影响因子：
6.4
通讯作者：
Yang, Rui
中科院分区：
文献类型：
--
作者：
Chang, Litao;Sun, Wenru;Yang, Rui
Inconel 718 粉末在代表性温度下进行热等静压 (HIPed)，以研究粉末压坯的微观结构、拉伸性能和拉伸断裂模式的变化。采用光学显微镜（OM）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等手段对粉末压坯的微观结构进行表征。结果表明，当粉末在1210℃及以下进行热等静压处理时，粉末中继承的枝晶间析出物部分保留在粉末压块中，而当粉末在1260℃及以上进行热等静压处理时，粉末压块中的枝晶间析出物被消除。随着热等静压温度的升高，粉末压块的晶粒尺寸均匀性先增大后减小。在 1260 摄氏度及以下的粉末压块中观察到先前的颗粒边界 (PPB)，但在 1275 摄氏度的热等静压处理时被消除。PPB 上装饰有碳化物颗粒，PPB 处碳化物颗粒的数量随着 HIPing 温度的升高而减少。大多数 PPB 在 1140 摄氏度下被 HIP 压坯中的碳化物颗粒钉扎。当 HIP 温度升高到 1210 摄氏度和 1260 摄氏度时，大量 PPB 脱钉并移动到钉扎碳化物颗粒之外，导致晶粒长大，并将碳化物颗粒留在新晶粒内原始 PPB 的位置。随着热等静压温度的升高，粉末压坯在650℃下的0.2%屈服强度降低，拉伸伸长率增大，拉伸断裂模式由颗粒间主导断裂转变为完全韧窝韧性断裂。 (c) 2014 Elsevier B.V. 保留所有权利。
Inconel 718 powders have been hot-isostatic-pressed (HIPed) at representative temperatures to investigate the variations in microstructure, tensile properties and tensile fracture mode of the powder compact. Microstructure of the powder compacts were characterized by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and so on. The results showed that the interdendritic precipitates inherited from the powders were partially retained in the powder compacts when the powders were HIPed at or below 1210 degrees C but were eliminated when HIPed at and above 1260 degrees C. The grain size uniformity of the powder compacts first increases and then decreases with increasing HIPing temperature. Prior particle boundaries (PPBs) were observed in the powder compacts HIPed at and below 1260 degrees C but was eliminated when HIPed at 1275 degrees C. The PPBs were decorated with carbide particles, the amount of the carbide particles at the PPBs decreases with increasing HIPing temperature. Most of the PPBs were pinned by the carbide particles in the compacts HIPed at 1140 degrees C. When the HIPing temperature was increased to 1210 degrees C and 1260 degrees C, a large number of PPBs de-pinned and moved beyond the pinning carbide particles, leading to grain growth and leaving carbide particles at the site of the original PPBs within the new grains. With increasing HIPing temperature, the 0.2% yield strength of the powder compacts at 650 degrees C decreases, the tensile elongation increases, and the tensile fracture mode changed from inter-particle dominant fracture to fully dimple ductile fracture. (c) 2014 Elsevier B.V. All rights reserved.