透明导电氧化物薄膜的抗伽马辐照性能研究

利用射频磁控溅射法制备出具有良好光电性能的In₂O₃: W（IWO）薄膜,与购置的In₂O₃: Sn（ITO）薄膜一起,在伽马射线地面加速模拟试验设备中进行辐照试验。对辐照前后两种薄膜样品的微观结构、表面形貌、光电性能和元素价态进行对比分析,并用正电子湮没方法研究辐照前后的缺陷情况。结果表明,伽马射线辐照可引起ITO及IWO薄膜样品中氧空位缺陷的少量增加,且缺陷主要产生于薄膜表层及薄膜与基底界面结合处。高能伽马光子作用于透明导电氧化物薄膜,主要通过破坏其内部结合能较低的化学键,并实现薄膜系统中元素之间的选择性重组。ITO与IWO具有良好的抗伽马辐照性能,IWO相比ITO更适合于抗伽马辐照相关应用。     

微型飞行器小展弦比薄翼流场中的翼尖涡特性分析

采用虚拟压缩方法求解三维不可压缩N-S方程,数值模拟了无弯度、有弯度两类微型飞行器低雷诺数小展弦比薄翼的流场,将得到的结果与实验进行了对比,数据间吻合较好.然后在此基础上分析了小展弦比薄翼的气动力特性,详细研究了小展弦比薄翼流场中翼尖涡的涡态结构及形成规律,在对小展弦比薄翼流场尾迹区的翼尖涡采用近似模型的基础上,对尾迹区翼尖涡的强度进行了分析.结果表明,翼尖涡是影响小展弦比薄翼气动力和流动分离特性的一个重要因素.     

An innovative constraining ring rolling process for manufacturing conical rings with thin sterna and high ribs

Conical rings with thin sterna and high ribs (CRTSHR) are key bearing-load parts of aerospace equipment, which are required to be manufactured with high performance and efficiency. Traditional ring rolling is the most preferred method for manufacturing high-performance ring parts, but it can hardly achieve the forming of CRTSHR due to the extreme geometry of CRTSHR. To solve this difficulty, an innovative constraining ring rolling process (CRR) is proposed in this paper to manufacture CRTSHR. To evaluate the proposed CRR and reveal its deformation behaviors, a thermomechanical coupled FE model for CRR of CRTSHR is established. Then, the experiment for CRR of CRTSHR is performed on a modified ring rolling machine, which proves that CRR of CRTSHR is feasible and the established FE model is reliable. Based on the reliable FE model, the metal flow mode in deformed CRTSHR is analyzed, and the deformation characteristics such as the stress state, strain distribution and the evolution of power parameters in CRR of CRTSHR are revealed. Finally, the influences of key parameters such as the friction factor between ring and molds, the diameter of idle roll and the feed velocity of idle roll on CRR of CRTSHR are investigated by FE simulation.     

航空发动机涡轮叶片接触式测温技术应用进展

航空发动机涡轮叶片测温技术能够揭示涡轮叶片的温度分布情况，对其开展性能评估、失效分析和优化设计具有重要意义。涡轮进口温度的不断提升对应用于航空发动机涡轮叶片的测温技术提出了更高的要求。现有的航空发动机涡轮叶片接触式测温技术可采集叶片表面温度和近表面气流温度，本文主要介绍了三种应用于涡轮叶片的接触式测温技术，包括薄膜热电偶、测温晶体和示温漆，简要说明了三种测温技术的工作原理，归纳了国内外应用现状，总结了各自的优势与不足，并对其发展方向进行了展望。     

Modelling and analysis of metal flowing behaviors in constraining ring rolling of tapered ring with thin wall and three high ribs

Tapered ring with thin wall and three high ribs(TRTWTHR), showing complicated geometry(wall thickness is less than 4 mm and rib height exceeds 20 mm), is extensively utilized to fabricate the critical structural parts of aerospace equipment such as spacecraft cabin, rocket body and fuel tank because of light weight and high carrying capacity. How to fabricate TRTWTHR with high performance is a critical problem that aerospace area needs to solve. In this work, constraining ring rolling(CRR) techn...