This work examines the effect of thermal modification temperatures in the production of thermally modified wood on the cutting and fracture parameters when cutting heat-treated spruce wood by a circular sawblade machine. The samples were thermally modified at 160, 180, 200, and 220 °C. One sample was unmodified and was used as a reference sample. On the basis of the performed experiments, the fracture parameters (fracture toughness and shear yield strength) were calculated for the axial–perpendicular direction of cutting. In comparison with the theoretical assumptions, the influence of temperature on the cutting and fracture parameters was confirmed. Thermally treated wood is characterized by increased fragility and susceptibility to crack formation, as well as reduced density, bending strength, and shear strength. These properties significantly affect the size of the cutting force and feed force, as well as the fracture parameters. As the temperature increases, the values of these parameters decrease. The mentioned material characteristics could be useful for the optimization of the cutting process, as well as for the issue of energy consumption during the machining of heat-treated wood.

This study investigates the influence of various tool coatings, cutting speeds, and feed per tooth values on cutting forces during the CNC milling of Medium Density Fiberboard (MDF). The coatings tested include reference, TripleSi, Hyperlox, DLC, and lapped coatings. Experiments were conducted using an SCM Morbidelli m100 CNC milling machine under controlled conditions. Cutting speeds were set at 8, 10, and 12 m/s, while feed per tooth values were varied at 0.1, 0.2, and 0.3 mm. Cutting forces were measured using a three-axis piezoelectric dynamometer Kistler, and the data were analyzed to determine the impact of these variables on cutting performance. The results revealed that while cutting speed had a minimal effect on cutting forces, feed per tooth significantly influenced them, with higher values of feed per tooth leading to increased forces. Among the coatings, lapped and TripleSi exhibited the lowest cutting forces, whereas DLC showed the highest. Statistical analysis, including ANOVA and Scheffé tests, confirmed the significant differences between the coatings and highlighted the superior performance of the lapped and TripleSi coatings in reducing cutting forces.

Anisotropic etching in potassium hydroxide (KOH) solution with electrochemical stop is commonly used in the formation of thin silicon membranes of sensitive elements in various microelectromechanical devices. However, there are almost no data on investigating the process of the electrochemical stop etching of elements for p–n junctions formed on a relief silicon surface. Here, the process of electrochemical stop etching in KOH solution for structures using n-silicon layers formed by diffusion on a p-silicon substrate with smooth and relief surfaces is studied. It is found that etching stops at the p–n-junction boundary when using a two-electrode circuit with a positive (relative to the solution) voltage applied to the n-type layer for a structure with an n-type layer formed on a smooth surface. As a result, a membrane, which is reasonably uniform in thickness over the entire area of wafer, manages to form. When using a two-electrode circuit for a structure with a relief surface, the current density is 70–100 times higher during etching than in the case of a smooth surface; etching is nonuniform over the wafer and stops long before achieving a p–n junction. It is found that etching stops at the p–n junction for a structure with a relief surface when using a circuit with two voltage sources and an additional negative (relative to the solution) voltage of –2.0 V applied to the p-type substrate. In this case, it is possible to obtain a silicon membrane, which is fairly uniform in thickness over the entire area of the wafer. The dependences of the density of current between the n-type layer of silicon and the solution on the etching time are obtained for structures with smooth and relief surfaces, which make it possible to determine the end of the etching process.