A calibration method for the installation pose of a line laser sensor suitable for serial-parallel machine tools is proposed to address the challenge of accurate pose calibration. Based on the characteristics of standard spheres to calculate the spherical center coordinates, an equation was established using the invariance of the sphere center, and a target function for calculating the rotation matrix was proposed. Point cloud data from the surface of the standard sphere was scanned, and the spherical center was fitted. A model for computing the translation matrix was developed by comparing the fitted center with the true center coordinates. Compared with a traditional hand-eye calibration method, the calibration errors of the proposed method in the X, Y, and Z directions have been reduced by 88.9%, 83.6%, and 82.1%, respectively. This method eliminates the need to alter the pose of the serial-parallel mechanism, effectively mitigating the impact of positioning errors on pose calibration, thus significantly enhancing calibration accuracy.

Thermal barrier coating (TBC) is a critical high-temperature protection technology applied to hot-section components of military and civilian aero-engines. Composed of a ceramic oxide top layer and a metallic bond coat, it significantly reduces the substrate operating temperature and offers technical advantages such as high hardness, excellent stability, resistance to high-temperature corrosion, reduces fuel consumption, and improves engine efficiency and service life. After initial preparation via atmospheric plasma spraying, the surface roughness of the coating is relatively high (approximately R_a10 μm). In production, grinding and polishing post-processing are commonly employed to reduce it to the required range (around R_a1.6 μm). This study proposes a spline path curve generation and feature point sampling method based on the RANSAC segmentation principle, applicable to robotic automated grinding and polishing of TBC on small turbine blades in aero-engines. The method utilizes a 3D vision sensor to scan the blade surface in real time, generating point cloud data. Through point cloud processing and B-spline curve fitting algorithms, a full-coverage grinding and polishing path for the high-temperature coating on the aero-engine blade surface is generated. Experimental verification demonstrates that this method reduces the coating surface roughness to below R_a0.7 μm while maintaining effective coating thickness, achieving precision grinding and polishing of TBCs on aero-engine blade surfaces.

This study systematically investigated the microstructural evolution, mechanical property mismatch, and their effects on fatigue performance in laser-remelted nickel-based superalloys through multiscale experimental characterization and finite element simulations. By combining nanoindentation tests, fatigue experiments, and an improved indentation inverse analysis algorithm, the spatial distribution of mechanical parameters in the remelting zone (RZ), remelting-affected zone (RAZ), and base material (BM) was quantified. The results demonstrate that the RZ, characterized by coarse columnar grains and Laves phase formation due to non-equilibrium solidification, exhibits significantly reduced strength compared to the BM. However, dendritic-cellular substructures within the RZ mitigate macroscopic performance anisotropy through grain boundary pinning effects. Although the RAZ shows elevated geometrically necessary dislocation (GND) density and twin boundary proliferation, residual tensile stresses lead to underestimated nominal hardness measurements. Fatigue analysis reveals a stress shielding effect in the heterogeneous material system: cyclic softening and mean stress relaxation in the RZ under high-stress conditions substantially reduce crack driving forces, shifting fatigue failure initiation to the BM. This work establishes a cross-scale theoretical framework for optimizing the performance of laser-repaired components.

The paper focus on the fatigue failure of welded joints affected by welding defects, fatigue and crack growth tests were conducted on 1Cr11Ni2W2MoV argon arc welded joints, which were used as certain engine’s combustion chamber case. Based on these tests, the NASGRO equation was established to describe the entire process of crack expansion in the welded joints. Then, the modified NASGRO model describing the whole process of crack expansion of the welded joints was established by considering the changes of threshold value and closure parameter in the expansion of the short cracks on the basis of the NASGRO model. Using modified model, the initial weld defects were equated to regular cracks, and the fatigue life of the welded joints under different stress levels was calculated by the crack growth method. Comparative analysis with the test results show that the model predictions are all within the twice dispersion band. The crack growth life prediction method developed in the paper provides certain guiding significance for the fatigue life study of welded joints considering the influence of defects.

With the substantial improvement in the demand for aero-engine performance, the main shaft bearings are facing harsher working conditions, which cause the working temperature and load of the bearings to increase dramatically. The friction and wear problems in bearings are becoming increasingly prominent, seriously affecting the service life and reliability of high-end equipment. The above problems bring new challenges to the optimization of M50 bearing steel material for aero-engine. Although the control technology of inclusions in bearing steel has made great progress, the control of primary carbide is still the key problem in the control of bearing materials. The paper summarizes the main research hotspots on friction and wear behavior of bearing steel at home and abroad, especially the sliding wear and rolling contact fatigue failure forms during service. The advantages and disadvantages of primary carbides in bearing steel in two kinds of friction and wear behaviors are pointed out, as well as their interrelationship. And based on the existing control methods of primary carbide, the future control strategy of primary carbide in bearing steel and the development goal of improving the friction and wear resistance of M50 bearing steel are put forward.

To improve the fatigue performance of turbine blade tenon, the surface integrity characteristics of K417G superalloy were studied by using a two-factor five-level response surface test method. The effects of shot peening intensity and coverage on surface roughness, residual stress, microhardness, and microstructure of K417G superalloy were investigated. Two response surface models of surface roughness and surface residual stress were established. The results show that, compared with shot peening coverage, shot peening intensity has a more significant effect on surface integrity characteristics. There is a saturation point of surface roughness with the increase of shot peening parameters. The error between the predicted and measured values of surface roughness and residual stress is less than 11% and 41%, respectively. When shot peening intensity is 0.13 mmA and coverage is 220%, better surface integrity characteristics can be obtained.

Inconel 718, as a typical difficult-to-cut material, exhibits high hardness, high strength, and low thermal conductivity. The tool is subjected to significant cutting forces and high cutting temperatures during the cutting process, which not only accelerate tool wear but also adversely affect the dimensional accuracy and surface quality of the machined parts. The straight slot features are widely present in aero-engine components, and the surface quality after finish machining decisively affects the service life and overall performance of the parts. A comparative analysis was conducted on the cutting performance of single-pass and multi-pass finish milling processes when machining straight slots of Inconel 718. The effects of different process methods on cutting force, surface topography, and material removal rate were investigated through theoretical derivation and milling experiments. The research findings indicate that single-pass finish milling of straight slots can effectively reduce the peak cutting force and the duration of force application, minimize milling tool deformation, achieve superior slot wall quality and floor surface accuracy, and enhance machining efficiency. Single-pass finish milling demonstrates significant advantages.

Aiming at the problem of accurately detecting and quantifying scratches and crater defects in compressor blades with existing methods, an algorithm based on structured light point cloud data is proposed. First, an IDW-NA point cloud feature enhancement algorithm, which integrates inverse distance weighted curvature and normal angle of large and small regions, is used to highlight the defects. In the defect localization process, the Otsu method (OTSU) is innovatively introduced to eliminate the limitations of manually setting thresholds, followed by the Z-score-based defect integrity expansion (ZDE) algorithm to achieve complete segmentation of the defects. Finally, the PCA algorithm is improved to perform quantitative analysis of the defects. Experimental results show that, compared to existing algorithms, the proposed method provides better performance in terms of defect segmentation integrity and continuity. The average absolute error of the final segmented defect size is no more than 0.105 mm, and the average percentage error is no more than 7.27%, confirming the accuracy and effectiveness of this approach.

The rotating blade is a key wearing part of aero-engine, so it is necessary to monitor its condition. Blade tip timing (BTT) is an effective non-contact monitoring method for rotating blades. However, the traditional BTT relies heavily on the once-per-revolution signal, and the BTT signal has serious under-sampling problem. In this paper, Orthogonal matching pursuit (OMP) method based on blade vibration difference is proposed to extract blade natural frequency. Firstly, a BTT sensor is used to calculate the blade vibration difference. Then, the sparse model of blade vibration difference is constructed, and the blade vibration difference signal is decomposed by OMP method under the condition of varying speed, and the vibration amplitude and natural frequency of the blades are extracted. The effectiveness and robustness of the proposed method are verified by numerical simulation, and experiments are carried out on the blade tip timing test bench. The results show that this method can accurately identify the amplitude and natural frequency of blade asynchronous vibration.

The balancing process post-assembly of engine’s high-pressure turbine rotor is pivotal to ensuring the operational stability of the engine. Simulated balancing techniques are widely employed in the balancing of engine rotor, during which the rotor calibrator serves as a balancing fixture. To enhance the inherent stability of the high-pressure turbine rotor calibrator during the balancing process, a multi-objective planning approach for coaxiality and perpendicularity assembly adjustment has been proposed. An assembly error propagation model for the rotor calibrator has been established to regulate the coaxiality and perpendicularity of the rotor calibrator assembly in response to field application requirements. An analysis of the three components assembly process of the high-pressure turbine rotor calibrator reveals that optimizing the coaxiality and perpendicularity of the rotor calibrator can be achieved by altering the assembly angles of components at each level. Under the premise of meeting the specified criteria, the assembly angles can be selected based on the requirements of the application site to minimize either coaxiality or perpendicularity.

In order to improve the concentricity level and stability of concentricity measurement results after the assembly of high pressure compressor rotors in aircraft engines, as well as the accuracy of predicting results during the assembly process, research has been conducted on issues such as the inability to optimize the perpendicularity of the rear end face of the components and poor repeatability of concentricity measurement results during the assembly of compressor rotors. By establishing the calculation model of the eccentricity of the middle section of the core machine rotor, found that the influence of the perpendicularity error of the back end face of the compressor rotor on the eccentricity of the middle section of the core machine rotor was 3.4 times that of the concentricity error. By establishing the datum correction model of the concentricity measurement process of the compressor rotor, it is analyzed that the reasons for the poor repeatability of the measurement results and the poor accuracy of prediction results are that the ratio of the rotor height to the radius of the reference end face is large, which makes the corrected results highly sensitive to the slight differences in the fitting surfaces of the reference end faces of the front shaft at different radial positions. Therefore, by reducing the ratio of the rotor height to the radius of the reference end face, taking the back end face as the measurement datum and improving the stack assembly direction, not only could the stability of the rotor concentricity measurement results be improved, but also the influence of the perpendicularity of the back end face could be considered in the stack optimization process. The verification results show that the concentricity error of the rotor is reduced by 68%, and the repeatability error of the measurement results decreases from 32% to 13%.