The measurement of cutting force is an effective method for machining condition monitoring in intelligent manufacturing. Titanium nitride films and silicon nitride films were prepared on 304 stainless steel substrates by DC-reactive magnetron sputtering and plasma-enhanced chemical vapor deposition (PECVD). The effects of substrate negative bias and nitrogen flow on the surface microstructures of TiN film were investigated. The smoothness of the film is optimal when the bias voltage is −60 V. X-ray diffraction (XRD) analysis was performed on the samples with the optimal smoothness, and it was found that when the nitrogen flow rate was higher than 2 sccm, the titanium nitride film had a mixed phase of TiN(111) and (200). It is further revealed that the change of peak intensity of TiN(200) can be enhanced by nitrogen flow. Through atomic force microscopy (AFM), it is found that the stronger the intensity of the TiN (200) peak, the smoother the surface of the film is. Finally, the effect of different film thicknesses on the hardness and toughness of the TiN/Si₃N₄ film system was studied by nanoindentation experiments. The nanohardness (H) of the TiN/Si₃N₄ film can reach 39.2 GPa, the elastic modulus (E) is 480.4 GPa, the optimal toughness value (H³/E²) is 0.261 GPa, and the sample has good insulation performance. Linear fitting of the film’s toughness to nanohardness shows that TiN/Si₃N₄ films with higher hardness usually have a higher H³/E² ratio.

Cutting force is one of the most basic signals that can reflect the information of the cutting process, so it is very necessary to study the strain elastic element of strain gauge wireless rotating dynamometers. This paper proposes a strain elastic element with a double-layer cross floating beam that can be applied to the strain gauge wireless rotating dynamometer, which can simultaneously obtain the four-component cutting force/torque information of $F_X$, $F_Y$, $F_Z$, and $M_Z$. Based on the proposed strain elastic element, a compact strain gauge wireless rotating dynamometer is designed, which is composed of a tool holder, upper connection flange, strain elastic element, lower connection flange, tool base, and data acquisition and wireless transmission system. The static model of the double-layer cross floating beam on the strain elastic element is established by the segmented rigid body method, and the relationships between the material, force, structural parameters, and the strain and deformation of the floating beam are obtained. The static model is consistent with the finite element solution, which proves the rationality of the static model. Based on the established static model, the sequential quadratic programming algorithm is used to optimize the structural parameters of the double-layer cross floating beam to maximize the sensitivity of the floating beam. The overall structure of the strain elastic element is analyzed by finite element software, and the strain of the structure under simulation conditions is obtained, which provides a reference for subsequent calibration tests and circuit design. The calibration matrix and dynamic performance of the strain elastic element are obtained by the static calibration test, dynamic calibration test, and cutting test. The results show that the proposed strain elastic element has high sensitivity and low cross-sensitivity error, and can be applied to the strain gauge wireless rotating dynamometer to measure medium- and low-speed cutting forces.

Barium titanate (BaTiO3, BTO) is a promising material for integrated photonics, but surface roughness introduced during thin-film growth degrades optical performance. An argon (Ar) ion-beam polishing process is developed for BTO thin films. The effects of ion energy, beam current, incidence angle, and removed thickness on surface morphology evolution are systematically examined. An incidence-angle response function is used to describe the angular dependence of the morphology evolution. At near-normal incidence (0° to −30°), grain-induced surface undulations are suppressed by ion-induced surface-parallel atomic redistribution, which promotes surface smoothing. An effective polishing window is identified at 300 eV, 100 mA, and 0° to −30°. Under these conditions, the root mean square roughness is reduced from 5.69 to 1.34 nm, corresponding to a 76.5% reduction. In addition, post-polishing annealing at 600 °C in oxygen helps relieve Ar-induced compressive stress and facilitates recrystallization in the near-surface damaged region. These results provide a practical polishing–annealing route toward the integration of high-quality BTO thin films into low-loss photonic devices.

Integrating barium titanate (BTO) films on SiO2/Si-based platforms is essential for the development of future nanophotonic modulators in photonic integrated circuits (PIC). However, the integration of BTO films on these amorphous platforms is far from trivial. In this work, the direct growth of tetragonal crystal (p4 mm)-textured BTO films on 4-in. SiO2/Si using a magnesium oxide (MgO) buffer layer by a magnetron sputtering process is developed. This work presents a systematic study on the evolution of crystallographic orientation and anisotropy energy in BTO films as a function of film thickness. Furthermore, a detailed analysis is conducted on the growth kinetics of BTO films, with the thickness-dependent evolution of surface morphology and Ba/Ti. Simultaneously, strain-engineered BTO films with a Curie temperature (Tc > 360 °C) are demonstrated. This integration method overcomes the lattice matching limitation between BTO and the amorphous substrate, offering a low-cost, flexible integration approach for next-generation PIC platforms.