In the aerospace field， welding serves as the primary joining process for TA3 alloy components，and the microstructure and mechanical properties of its welded joints have a significant impact on the service safety of welded components. This study compares the tensile properties of the base metal and welded specimens and studies the deformation morphology before and after tension using scanning electron microscopy combined with electron backscatter diffraction. The results show that the microstructure of TA3 alloy is equiaxed α grains before welding， and massive， acicular and serrated α grains appear after welding. The yield strength （378 MPa） and tensile strength （458 MPa） of welded specimens are higher than that of base material specimens， but the elongation is lower. The reason is that after the base meterial sample is welded， the welding temperature has the effect of aging treatment on the sample. There exists aging hardening， and the grain size inside the weld area becomes smaller， which will increase the tensile strength. Because the microhardness of the weld zone is obviously higher than that of the base metal zone， the fracture of the welded joint is located in the base meterial zone. The deformation mechanism of the weld zone is stress-induced deformation twin （\mathrm{2}\overline{\mathrm{1}}\overline{\mathrm{1}}2）［\mathrm{2}\overline{\mathrm{1}}\overline{\mathrm{1}}3］ and （\overline{\mathrm{2}}\mathrm{1}12）［\overline{\mathrm{2}}\mathrm{1}13］， with a Schmid factor of 0.038， exhibiting high shear stress and strong coordination of grain deformation. Deformation twins （\overline{\mathrm{2}}\mathrm{11}2）［\mathrm{2}\overline{\mathrm{1}}\overline{\mathrm{1}}3］ also appear in the base material region， but the Schmid factor is 0.078， indicating a relatively high degree of stress concentration.

Based on the current status and requirements of wear in zirconia ceramics， in response to the problem friction reduction performance of single-textured specimens， different texture types are combined to extract biomimetic contours from biological surfaces and design various novel composite biomimetic textures. The numerical simulation and the experimental investigation methods are used to analyze the friction reduction performance of composite biomimetic textures，solving the Reynolds equation numerically， studying the influence of composite texture types on oil film load capacity， pressure distribution area， and maximum static pressure， and conducting experimental exploration of the tribological performance using a friction and wear testing machine. The results indicate that composite biomimetic textures exhibit higher oil film load capacity， wider pressure distribution areas， and lower friction coefficients compared to other texture types， among them， the comprehensive anti-friction effect of the scale + feather composite texture is the best； the friction reduction mechanism of composite biomimetic textures can be mainly attributed to changes in contact stress points， the asymmetric distribution of pressure and abrasive storage properties， and the form of pressure distribution of composite texture is highly dependent on a single texture type.

With the improvement in aeroengine performance，critical components （such as centrifugal impellers） operate under high-temperature，high-stress，and complex load conditions. Geometric discontinuities （such as ventilation holes and fillet radii） have become weak points for fatigue failure. This study focused on TA19 material，preparing smooth and U-shaped notch specimens for low-cycle fatigue tests under high-temperature conditions. Fatigue life data have fitted using the Weibull distribution，and an improved iterative fatigue life model is proposed to address the limitations of traditional models in regions with stress concentration. The model incorporates the stress concentration factor （K_t） and first-order reliability theory for correction. The results indicate that due to stress concentration effects，U-shaped notch specimens exhibit more concentrated fatigue life distributions，whereas smooth specimens show greater variability. The Kolmogorov-Smirnov test verifies that the data conforms to the Weibull distribution characteristics. The revised model significantly improves the prediction accuracy，with most of the predicted data falling within±1.5 times the scatter band. Additionally，P-S-N curves for different failure probabilities are constructed，providing a valuable reference for the reliable fatigue life prediction of complex structures.