Magnesium rare-earth (Mg – RE) alloys exhibit the advantages of low densities, high specific strength and specific stiffness, desirable heat resistance, and good damping properties. The application of Mg–RE alloys in the aero-engine components can effectively reduce the equipment weight and system noise, improve the load capacity and maneuverability of aircraft. In this article, the classification of cast Mg–RE alloys is first introduced with different strengthening mechanisms. Various casting processes are reviewed and their effects on the microstructure and properties of Mg–RE alloys are also analyzed. Then the requirements for the use of Mg alloys in the existing aero-engine airworthiness standards and general standards are summarized, following by the application status of casting Mg–RE alloys in aero-engine and some other aerospace components at home and abroad. Finally, the problems and development trends of Mg–RE alloys used in aero-engine are discussed according to the actual engineering application requirements.

Aircraft structure is the foundation of aircraft platform and the most important bearing structure to ensure the safe and long-life use of aircraft. With the continuous development of aviation technology, aircraft design ideas continue to evolve and develop, and higher requirements are constantly put forward for the structural performance of aircraft body. The severe service environment and strict comprehensive functional/performance requirements make the structural integrity face major challenges. Aircraft structural health monitoring and management technology has the advantages of real-time and linearity. It is one of the important technical ways to ensure structural safety and reduce maintenance costs. Starting from the outline of aircraft structural integrity, this paper explains the basic connotation, tasks and implementation methods of aircraft structural health monitoring and management technology, summarizes the latest technical progress in this field at home and abroad, and looks forward to the development trend of structural health monitoring and management technology in combination with the development status of aircraft structural health monitoring and management technology in China.

At present, the operating temperatures of aero-engines and gas turbines have exceeded 1000℃ , and the performance of traditional bond coat material MCrAlY has gradually been unable to meet the demand. NiAl intermetallic has high melting point, low density, low cost and excellent oxidation resistance, which offers its great potential in application. However, the high temperature strength of NiAl is low and the adhesion of its oxide scale is poor, so it is compulsory to modify NiAl to enhance its high-temperature performance by doping platinum group elements (Pt, Ru, Pd, etc.), reactive elements (Hf, Zr, Dy, etc.) and nanocrystalline particles (CeO₂ , Al₂O₃ , ZrC, etc.). The different roles of these doping manners are briefly summarized. By doping alone or together, the growth rate of TGO can be slowed down, the mutual diffusion coefficient can be reduced, the adhesion of oxide scale can be increased, and the overall performance of NiAl coating can be improved.

As the continuous development of aero – engine towards high fuel efficiency and high thrust weight ratio, the service conditions of thermal barrier coating on the surface of engine hot-section components are becoming more and more stringent. As a new type of thermal barrier coating material, the development and application of rare earth zirconate have attracted more and more attention from scholars at home and abroad. In a series of rare earth zirconates, Sm₂Zr₂O₇ has the advantages of stable pyrochlore structure, low thermal conductivity and high coefficient of thermal expansion. In order to meet the higher service requirements of thermal barrier coatings, the doping modification and performance evaluation of Sm₂Zr₂O₇ have increasingly become an important research hotspot. Firstly, this paper briefly summarizes the thermal barrier coating materials, and then Sm₂Zr₂O₇ based ceramic materials and its corresponding coatings are investigated from the views of crystal structure, thermophysical properties, mechanical properties and corrosion resistance in detail. And the results could provide a reference for the research and application of Sm₂Zr₂O₇ in the field of advanced thermal barrier coatings.

An environmental barrier coating system was applied on SiC_f /SiC composite specimens with the silicon bond coat and mullite intermediate coat sprayed using APS processes and the ytterbium silicate topcoat sprayed using a PS–PVD process. The sprayed environmental barrier coating system is dense in microstructure and the PS–PVD ytterbium silicate topcoat possesses lamellar structure with a porosity less than 1%. The static oxidation, cyclic oxidation, water vapour corrosion and thermal impact resistances of the environmental barrier coating system were investigated. It was demonstrated that the environmental barrier coating sprayed on the SiC_f/SiC composite specimens had a desirable oxidation resistance as it kept intact with no obvious evidence of spallation observed after 100h static oxidation, 100h cyclic oxidation test at 1200℃ and 1300℃. Moreover, the coating had a thermal impact resistance life more than 100 cycles as heated to a high temperature of 1300℃ by a hot gas stream and it had a preferable corrosion resistance at 1200℃ in an environment containing 15% H₂O water vapour.

Accurate temperature monitoring in thermal barrier coatings on turbine blades is of paramount importance for the design and development of aero-engines and gas turbines. Recently, a new on-line temperature measurement technology using thermal barrier sensor coatings and a new off-line temperature measurement technology using thermal history sensor coatings based on temperature-dependent phosphorescence properties of thermographic phosphors are both developed rapidly. The former obtains the real-time temperature by on-line measuring the phosphorescent signal, and the later obtains the exposure temperature by off-line measuring the irreversible changes in the phosphorescence properties after operation. Both of these technologies are suitable for non-interference, non-contact, high-precision temperature measurement of thermal barrier coatings under high temperature and high corrosion environments, and have broad application prospects. According to the introduction of the principles and methods of on-line/off-line temperature measurement in thermal barrier coatings, thermal barrier sensor and thermal history sensor materials and preparation, their applications in aero-engines and gas turbines, the research status and technical characteristics of on-line/off-line temperature measurement technology of thermal barrier coatings are described in detail. Finally, the development of the two technologies is also prospected.

Application of thermal barrier coatings (TBCs) is increasing in a variety of commercial and military fields associated with high temperatures. Accordingly, the quest for developments related to TBC systems is considered a key area of research. Numerous TBCs materials based on the new high-entropy concept have been developed. It is noteworthy that many of these materials possess technologically appealing and tunable properties, such as high phase stability, ultra-low thermal conductivity, excellent corrosion resistance, large thermal expansion coefficient, and outstanding fracture toughness. All these features make them attractive in the fields of aerospace, navigation, and nuclear energy. The present study focuses on the recent development of high-entropy-based TBCs materials. Major themes in this assessment include a taxonomy of current ceramics families, microstructures, physical properties, and future applications. This review is expected to shed light on the fundamental investigations and further TBCs applications of the recently developed high-entropy ceramics.

The effects of penetrating holes on the tensile properties of titanium honeycomb panels with variable cross-section used in aircraft structure was studied experimentally and numerically. Among them, the finite element model included the details of the honeycomb core and the detailed structure of the bevel area was established by parametric modeling method. The results showed that the bevel area was the weak part of the titanium honeycomb panels with variable cross-section, the failure mode of the specimen without hole was the cross section fracture along the chamfer of the skin in the initial area of bevel. For the panels with penetrating hole, there was a diameter threshold of 40mm. When the penetrating hole diameter was less than the threshold, the failure mode and tensile fracture load of the panels with penetrating hole were consistent with the panels without hole. When the penetrating hole diameter exceeded the threshold, the failure mode of the panels with penetrating hole changed to fracture along the cross-section of penetrating hole and the tensile fracture load decreased linearly with the increase of the diameter of penetrating hole.

Multi-pass amplifier technology becomes the main development direction of high power solid-state laser driver, it is necessary to debug and maintain the laser optical path and establish the mathematical model and adjustment scheme of the beam alignment. Using matrix optics method, a multi-pass amplifying automatic collimation system mathematical model is set up, the far and near field laser facula offset is obtained with the analytical expression of the adjustment quantity. The feasibility of light path principle and adjustment method of automatic collimation system is validated.

In order to meet the demands of company’s strategic planning and increased customer delivery quantity, the systematic layout planning (SLP) method was used to optimize the layout of tail cone production line. Firstly, the theory of systematic layout planning method was introduced, then the ramp up of tail cone production line was analyzed and calculated, including the calculation of production line balance ratio, identification of key bottleneck stations, and analysis of manning and key equipment required. Secondly, the position calculation and analysis of the jigs in tail cone production line were conducted by using the relationship chart, spatial relationship diagram to obtain various layout schemes of tail cone production line. Finally, according to the principles of lean production line layout, the above layout schemes were discussed and evaluated, then the optimum layout was determined by comprehensive evaluation.

With the improvement of machine tool processing performance and tool cutting performance, high efficiency and high precision machining of aviation structural parts becomes possible. There are many thin-wall features of aviation structural parts, which are prone to deformation during the milling process. Therefore, the prediction and control of aviation structural parts deformation is an urgent problem to be solved in the field of machining. Through summarizing the characteristics and processing difficulties of aviation structural parts, the forming mechanism of machining deformation is deeply analyzed. This paper summarizes the milling force model that is most critical to processing deformation, and explains the research progress of residual stress and deformation prediction of aviation structural parts. Machining process optimization, numerical control compensation technology and high-speed cutting technology are the main strategies to realize the deformation control of aviation structural parts. Finally, the future development is forecasted.

Titanium matrix composites is a kind of typical hard-to-cut materials, and traditional machining methods have problems such as low machining efficiency and poor machining quality. To this end, experimental investigation on electrochemical drilling of (TiB+TiC)/TC4 composites using a tubular cathode with a diameter of 10mm was conducted. The electrochemical characteristics of (TiB+TiC)/TC4 composites were studied. The polarization curves and current efficiency of (TiB+TiC)/TC4 composites in 10% NaNO₃ solution were measured. The influence of processing voltage and electrolyte pressure on processing accuracy was explored. The results show that when the machining voltage is 30V and the electrolyte pressure is 0.6MPa, the electrochemical drilling process is stably at a feed speed of 1mm/min. When the depth-to-diameter ratio of the machined blind hole is 3.06, the roundness error of the hole is 41.1μm and the taper is 0.4°, which shows the high machining accuracy of the electrochemical drilling method.