The stress intensity factor represents a vital parameter within the realm of linear elastic fracture mechanics. It acts as the cornerstone in determining crack propagation and evaluating damage tolerance. However, calculating this factor is a complex task. To surmount this challenge, models of the stress intensity factor for both edge and center cracks were developed using the extended finite element method. The result of this effort is the ability to calculate the stress intensity factor at the crack tip under different loads and normalized crack lengths. The accuracy of these calculations was confirmed by comparing them to results from the NASGRO method, and the optimal mesh sizes for both the crack elements and overall units were established. Further analysis, conducted through MATLAB’s regression analysis, led to the development of an empirical model. This model was found to be both simple and reliable, making it an ideal tool for engineering applications.

Shot peening technology is usually employed to improve the ability of mechanical parts to resist failure due to fatigue and wear. It is often used to strengthen the surface of a target, but the induced residual stress and its distribution with respect to the coverage can affect the performance of the shot peening process. In this study, a comprehensive numerical and experimental study was conducted to overcome these issues. Using numerical simulation we found that both the surface and subsurface residual stress increases with the increase of the coverage before stabilizing. Quantitative analysis using the Entropy Method indicates that under the shot peening parameters considered in the simulation coverage of 200% is best for the shot peening of ZGMn13 High Manganese Steel. The following experimental study agreed with the corresponding numerical data for the residual stresses at varied depths from surface to subsurface with errors of less than 25%. Thus, the related research outcomes can guide the shot peening process to obtain the optimized surface strengthening of the target.

Reaction-Bonded Silicon Carbide (RB-SiC) ceramics possessing excellent mechanical and chemical properties, whose surface integrities have an essential effect on their performance and service life, have been widely used as substrates in the core parts of aerospace, optics and semiconductors industries. The single abrasive scratching test is considered as the effective way to provide the fundamental material removal mechanisms in the abrasive lapping and polishing of RB-SiC ceramics for the best surface finish. In this study, a novel single abrasive scratching test with an increasing scratching depth has been properly designed to represent the real abrasive lapping and polishing process and employed to experimentally investigate the surface integrity regarding different scratching speeds. Three typical and different material removal stages, including the ductile mode, ductile–brittle transition mode and brittle mode, can be clearly distinguished and it is found that in the ductile material removal stage by increasing the scratching speed would inhibit the plastic deformation and improve its surface integrity. It is also found that in the ductile–brittle transition and brittle material removal stages, to increase the scratching speed would inhibit the plastic deformation due to the fast scratching speed that limits the time of plastic deformation on the target, but it also results in the increased length of lateral cracks with the increased scratching speed which can reflect that the size of brittle chips, like brittle fractures and large grain fragmentations, increases as the scratching speed increases. It can provide the references for the optimization of the abrasive lapping and polishing of RB-SiC ceramics with high efficiency and surface quality.

Titanium alloys are extensively utilized in the aerospace industry due to their exceptional properties, encompassing high specific strength and corrosion resistance. Nevertheless, these alloys present inherent challenges as difficult-to-machine materials characterized by low thermal conductivity and high chemical reactivity. The machining of titanium alloys often gives rise to elevated cutting forces and temperatures, thereby resulting in compromised machining quality and substantial tool wear. This study explores the influence of the cutting-edge shape factor on tool performance and optimizes the cutting-edge structure through finite element simulation. Remarkably, the cutting performance of the tool demonstrates significant enhancement following cutting-edge passivation. Alterations in the geometric shape of the cutting-edge after passivation exert a notable impact on the tool’s cutting performance, with a superior performance observed for shape factor K > 1 compared to alternative edge structures. Additionally, numerical simulation is employed to analyze the influence of passivation values Sγ and Sα on cutting force and temperature, which are crucial factors affecting cutting performance. The results underscore the significant impact of Sγ on cutting force and temperature. Furthermore, within the confines of maintaining an identical shape factor K, the blade segment group featuring Sγ = 40 μm and Sα = 25 μm exhibits the lowest maximum cutting temperature, thereby indicating the optimal tool design attainable through this study.