To further improve prediction accuracy and optimization quality of wire electrical discharge machining of SiCp/Al composite, trim cuts were performed using Taguchi experiment method to investigate the influence of cutting parameters, such as pulse duration ( T_on), pulse interval ( T_off), water pressure ( W_p), and wire tension ( W_t)), on material removal rate and three-dimensional surface characteristics ( S_q and S_a). An optimization model to predict material removal rate and surface quality was developed using a novel hybrid Gaussian process regression and wolf pack algorithm approach based on experiment results. Compared with linear regression model and back propagation neural network, the availability of Gaussian process regression is confirmed by experimental data. Results show that the worst average predictive error of five independent tests for material removal rate, S_q, and S_a are not more than 10.66%, 19.85%, and 22.4%, respectively. The proposed method in this article is an effective method to optimize the process parameters for guiding the actual wire electrical discharge machining process.

The purpose of this paper is to study the thermal shock resistance and failure mechanism of La₂Ce₂O₇/8YSZ double-ceramic-layer thermal barrier coatings (LC/8YSZ DCL TBCs) under extreme temperature gradients. At high surface temperatures, thermal shock and infrared temperature measuring modules were used to determine the thermal cycling life and insulation temperature of LC/8YSZ DCL TBCs under extreme temperature gradients by an oxygen–acetylene gas flame testing machine. A viscoelastic model was used to obtain the stress law of solid phase sintering of a coating system using the finite element method. Results and Conclusion: (1) Thermal cycling life was affected by the surface temperature of LC/8YSZ DCL TBCs and decreased sharply with the increase of surface temperature. (2) The LC ceramic surface of the failure coating was sintered, and the higher the temperature, the faster the sintering process. (3) Accelerated life test results showed that high temperature thermal cycling life is not only related to thermal fatigue of ceramic layer, but is also related to the sintering degree of the coating. (4) Although the high temperature thermal stress had great influence on the coating, great sintering stress was produced with sintering of the LC ceramic layer, which is the main cause of LC/8YSZ DCL TBC failure. The above results indicate that for new TBC ceramic materials, especially those for engines above class F, their sinterability should be fully considered. Sintering affects the thermal shock properties at high temperature. Our research results can provide reference for material selection and high temperature performance research.

The stress distribution of the ZF6400/19/32 hydraulic support under combined conditions is a challenging problem since the complexity of the working condition. In this paper, We studied the stress distribution characteristics of hydraulic supports under the combined conditions of the canopy bending & the base horizontal loading, the canopy hind torsion & the base bending. And the dangerous and weak areas of the hydraulic support under various working conditions are determined. The original design scheme of the ZF6400/19/32 hydraulic support is improved and optimized based on the analysis results. The research provides useful reference for the design of the hydraulic support, and improves the hydraulic support safety and reliability in the actual work.