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Silicon, glass, and other hard and brittle materials exhibit strong inertness and chemical stability and are ideal substrates for preparing macrochannels. To prepare microchannels with hard and brittle material through high-precision and high-efficiency machining, the author innovatively proposed a new technology called template-based electrophoretically assisted micro-ultrasonic machining (TBEPAMUSM). The microchannel shape punch-pin was transferred to a workpiece by micro-ultrasonic machining (MUSM). Due to the electrophoretic characteristics of ultrafine abrasive particles, applying a DC field can ensure that ultrafine abrasive particles are present in the machining area. Four process parameter (average particle size, particle concentration, ultrasonic power, and electrophoretic DC voltage) single-factor experiments and orthogonal experiments were carried out for TBEPAMUSM. The single-factor experimental study indicated that (1) an increase in the average particle size and ultrasonic power can effectively improve the material removal rate (MRR), but the surface roughness (SR) also decreases. (2) An increase in the abrasive concentration reduces the SR, but a suitable concentration can maximize the MRR. (3) When a suitable DC voltage is introduced, the MRR and SR can be effectively improved. The orthogonal experiment results show that the average particle size exerts the greatest effect on the SR and MRR. Considering the balance between machining quality and machining efficiency, the optimal parameters were as follows: ultrasonic power 70%, average abrasive particle size 18 μm, abrasive concentration 18%, and DC voltage 40 V. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low machining accuracy and more serious tool wear in the traditional diamond grinding machining (DGM) microstructure of hard and brittle materials, this paper proposes high-speed rotary ultrasonic machining (HRUM) technology and develops a HRUM machine tool. The hardware part of the machine tool mainly includes the spindle module, micro-motion system module, ultrasonic machining tank module, and data acquisition (DAQ) system module. The LabView-based controlled machining control system, including motion selection, initialization, coarse tool setting, constant force tool setting, control machining, and coordinate display module, is developed. Comparative experimental research of the HRUM and DGM of small holes in Al2O3 ceramics is carried out in the developed HRUM machine tool. The results demonstrate that HRUM effectively reduces axial cutting forces, reduces binder adhesion, and suppresses slippage while improving tool-cutting ability and extending tool life compared to DGM under the same machining parameters. This technology has essential research significance for the high-precision and efficient machining of microstructures in hard and brittle materials. [ABSTRACT FROM AUTHOR]

Micro-ultrasonic machining (MUSM) is an effective way of processing microstructures made from hard and brittle materials, although controlling the fluctuation of the machining force during processing is difficult. To control the quality of micro-holes fabricated in hard and brittle materials, MUSM with force control (MUSMFC) is used to study the edge chipping rate (ECR) and material removal rate (MRR) during micro-hole fabrication. The process is controlled using a force sensor and a processing control strategy. Various experiments are designed to assess the processing efficacy. Comparative experiments indicate that the ECR with MUSMFC is superior to that with traditional MUSM. Single-factor experiments show that the ultrasonic power and the fluctuation of the machining force exert a significant influence on the ECR. The influence of the spindle speed on the ECR is small. Orthogonal experiments show that the fluctuations of the machining force and ultrasonic power have large impacts on the MRR. The spindle speed has a significant impact on the MRR as well, whereas the mass fraction has little effect. The best combination of ECR and MRR is obtained using a spindle speed of 500 rpm, a machining-force fluctuation of 0.1 N, an ultrasonic power of 50 W, and a mass fraction of 10%. [ABSTRACT FROM AUTHOR]