莫来石基耐火材料夹杂物与粉末冶金高温合金FGH96界面反应  

Interfacial reaction between mullite-based inclusions and PM superalloy FGH96

作　　者：张轶波 郑亮 许文勇 李周 张国庆 ZHANG Yibo;ZHENG Liang;XU Wenyong;LI Zhou;ZHANG Guoqing(Science and Technology on Advanced High Temperature Structural Materials Laboratory,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《航空材料学报》2022年第2期20-28,共9页Journal of Aeronautical Materials

基　　金：国家重点研发计划(2019YFA0705300);国家自然科学基金(52071310、91860131);国家科技重大专项(Y2019-VII-0011-0151)。

摘　　要：采用光学金相显微镜(OM)、扫描电镜(SEM)及电解腐蚀方法研究粉末冶金高温合金FGH96中人工植入莫来石基耐火材料夹杂物在原始颗粒态、热等静压和热变形过程中形貌和成分的演变规律,揭示莫来石基夹杂物与合金基体发生界面反应的机制。结果表明:在原始颗粒态时,人工植入的莫来石基夹杂物为无规则颗粒状;经过高温高压的热等静压固结成形后,夹杂物内部形态和成分未发生明显变化,但夹杂物与基体界面发生置换反应形成了结构复杂的反应层,该反应层由Al、Ti的氧化物构成,并含有较多孔隙。经过25%变形量(温度1080℃、应变速率0.0004 s;)的热变形后,夹杂物主体形态和成分未发生明显变化,而夹杂物外部包覆的反应层随高温合金基体的变形开始从夹杂物上剥离和拉长,并随着金属基体的流动变形,在靠近拉长方向一侧发生聚集;当变形程度为50%时,莫来石夹杂物连同外部包覆的反应层发生破碎变形,形成夹杂物碎块加反应层的复合形态,该复合形态夹杂物呈线状分布,长轴垂直于压缩方向;当夹杂物外部包覆的反应层被剥离、莫来石夹杂物本体破碎后,形成的暴露于高温合金基体的新表面将继续反应生成新反应层,破碎的莫来石夹杂物本体仍然以O、Al、Si为主要组成,但同时含有少量Ni、Cr、Ti、Co、Mo等高温合金中的元素。The morphology and chemical composition evolution of mullite based refractory inclusions in FGH96 PM superalloy with powder state, hot isostatic pressing(HIP) and hot deformation(HF) were studied by means of artificial implantation of inclusions, optical microscopy(OM), scanning electron microscopy(SEM) and electrolytic etching. The mechanism of interfacial reaction between mullite based refractory inclusions and alloy matrix was revealed. The results show that in the powder state, the artificial mullite based inclusions are irregular particles, and there is no obvious change of morphology and composition in the inclusions after HIP process at high temperature and high pressure. A complex reaction layer is formed at the interface between inclusions and alloy matrix. The reaction layer is consisted of Al and Ti oxides. After thermal deformation of 1080 ℃/0.0004 s;under the condition of 25% deformation rate, the main morphology and composition of the inclusions are not changed obviously. The reaction layer coated on the inclusion began to peel and elongate from the inclusion with the deformation of the superalloy matrix,and aggregated on the side close to the elongation direction with the flow deformation of the matrix. When the deformation degree is 50%, mullite inclusions and the externally coated reaction layer are broken and deformed to form an inclusion fragments and reaction layer. The inclusions in the composite form are distributed linearly, and the long axis is perpendicular to the compression direction.When the reaction layer coated outside the inclusion is stripped and the mullite inclusion is broken to form a new surface exposed to the superalloy matrix, the reaction continues to form a new reaction layer. The crushed mullite inclusion is still dominated by O, Al and Si, but it also contains a small amount of element in the superalloy such as Ni, Cr, Ti, Co and Mo.

关 键 词：FGH4096粉末高温合金 莫来石 夹杂物 界面反应 变化特征 

分 类 号：TG132.32[一般工业技术—材料科学与工程]