摘要
【目的】随着燃气轮机发动机逐渐实现自主研发,被誉为“皇冠上的明珠”的发动机叶片研发备受关注,燃气轮机发动机的叶片部分为空心叶片,陶瓷型芯是形成空心叶片内腔的主要部件。由于燃机发动机空心叶片的尺寸较大,在浇注过程中高温保温时长相对较长,使得陶瓷型芯在高温保持的时间也随之延长。为确保陶瓷型芯满足大尺寸空心叶片的铸造要求,对其长时高温蠕变行为的研究尤为重要。因此,本文聚焦氧化铝含量对硅基陶瓷型芯长时高温蠕变行为的影响展开研究。【方法】以熔融石英为基体,制备不同氧化铝含量的硅基陶瓷型芯样品。样品经过1200℃烧结后,采用悬挂法进行1500℃保温1 h的蠕变测试实验,观察陶瓷型芯蠕变变形特征并测量蠕变变形量;采用扫描电镜(SEM)观察陶瓷型芯蠕变后样品的断口微观组织,利用X射线衍射(XRD)设备分析不同状态下陶瓷型芯的相组成。【结果】当氧化铝质量分数为20%时,陶瓷型芯的显孔率最低,且烧结后及1500℃/1 h保温后的方石英相对含量均最高;当氧化铝质量分数为10%时,陶瓷型芯的蠕变变形量最小。氧化铝含量较高时,其与二氧化硅在高温下发生反应,会促进黏性流动烧结,进而导致陶瓷型芯蠕变变形增大。【结论】氧化铝对硅基陶瓷型芯烧结过程中熔融石英向方石英的相转变具有一定促进作用;经高温保温后,随着氧化铝含量的升高,氧化铝会参与反应形成莫来石相,引发黏性流动烧结,从而增大陶瓷型芯的蠕变变形量。若要获得高强度、长时蠕变性能优异的硅基陶瓷型芯,需要合理控制氧化铝添加量。
[Objective]With the gradual achievement of independent research and development of gas turbine engines,the research and development of turbine blades,known as the“jewel in the crown”,have attracted much attention.A part of the gas turbine blades are hollow in structure,and the ceramic cores are the main components that form the hollow blade cavity structure.Due to the large size of the hollow blade,the high-temperature casting time is much longer,and this leads to an extension of the high-temperature holding time of the ceramic core.To ensure that the ceramic core meets the casting requirements of large-sized hollow blades,it is particularly important to consider the long-term high-temperature creep behavior of the ceramic core.Therefore,the effect of alumina content on the long-term high-temperature creep behavior of silica-based ceramic cores was investigated in this paper.[Methods]First,fused silica was selected as the matrix,and the silica-based ceramic cores with different alumina contents were prepared.After sintering at 1200℃,a creep test was conducted at 1500℃for 1 h using the suspension method,during which the creep deformation characteristics were observed and the deformation amount was measured.Scanning electron microscopy(SEM)was used to observe the fracture microstructures of the ceramic cores after creep at high temperature.X-ray diffraction(XRD)was used to analyze the phase compositions of the ceramic cores in different states.[Results]It is indicated that for the samples with 20%alumina,the least porosity and the highest relative cristobalite content were detected after sintering and subsequent 1500℃for 1 h heat treatment.When the alumina content is 10%,the lowest creep deformation amount is obtained.The reaction between alumina and silica at high-temperature promotes viscous flow sintering,which increases the creep deformation of the ceramic cores.[Conclusions]Adding alumina can promote the phase transformation from fused silica to cristobalite during the sintering process.After high-temperature holding,as the content of alumina increases,alumina participates in the reaction,forming the mullite phase,causing viscous flow sintering and increasing the creep deformation amounts of the ceramic cores.To obtain silica-based ceramic cores with high strength and excellent long-term creep properties,it is necessary to reasonably control the content of alumina.
作者
李凯文
刘丽荣
谷星筱
董加胜
姜卫国
LI Kaiwen;LIU Lirong;GU Xingxiao;DONG Jiasheng;JIANG Weiguo(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China;Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research of Chinese Academy of Sciences,Shenyang 161100,Liaoning,China;Department of Mechanical and Electrical Information,Weifang University of Science and Technology,Weifang 262700,Shandong,China)
出处
《沈阳工业大学学报》
北大核心
2026年第1期93-98,共6页
Journal of Shenyang University of Technology
基金
中国科学院先导C项目(XDC0160200)。
关键词
氧化铝
硅基陶瓷型芯
方石英
高温蠕变
蠕变变形量
断口形貌
显孔率
黏性流动烧结
alumina
silica-based ceramic core
cristobalite
high-temperature creep
creep deformation amount
fracture morphology
porosity
viscous flow sintering
