Current chairside CAD/CAM system produces unsatisfactory surface quality on dental restorations made from lithium metasilicate/disilicate glass-ceramics (LMGC/LDGC). This paper reports a microgrinding of these two materials at 1–5 μm depths of cut with Φ500 μm #320 and #600 diamond tools. The lowest 3D average roughness achieves 234±12 nm and 168±11 nm for LMGC and LDGC, respectively. They are 79% and 97% lower than current dental processes, and comparable to health human teeth. The materials removal mechanism includes both localized ductile removal and brittle fracture. This means fully-ductile removal is feasible on these materials by microgrinding and its potential to advance current dental manufacturing.

In machining operations, elevated cutting temperature accelerates the tool wear and have a negative impact on the geometry precision and surface integrity of the workpiece. Thus, it’s necessary to monitor the tool temperature by in-process measurement techniques. However, due to the extreme environment with great pressure and high temperature in the tool-chip contact area, previous cutting temperature measurement methods were lack of flexibility, durability and precision. In this paper, we introduce an improved cutting temperature method with wireless embedded sensors which can continuously measure the tool edge temperature in high-speed manufacturing process featured by high precision and fast response. For the purpose of reducing the sensor response time and minimize the influence on temperature field on the tool surface, the sensors have extremely small dimensional size as well as thinner hot junctions. Turning experiments have conducted to investigate the performance of sensor integrated insert in monitoring the cutting temperature. Consequently, the integrated sensors not only function well within a long duration but also show good sensitivity and improved response time during the cutting tests.

It is believable that the discharge reaction force waveform coincides with the behavior of the bubble generated in the interelectrode gap in electrical discharge machining. As to the discharge reaction force in wire electrical discharge machining (WEDM), it was found that there are two main peaks for each discharge reaction force waveform. The interval time between these two peaks is employed to establish the relationship between discharge reaction force and behaviors of bubble. In this study, firstly the relationship between the interval time and bubble behavior was clarified. Then, a series of experiments were performed to explore a setup for measuring the discharge reaction force acting on the wire electrode.

As it is known that in EDM discharge does not occur immediately after the application of open voltage, there is always a certain discharge delay time. This discharge delay time can reflect the dielectric breakdown strength of the gap between the tool electrode and the workpiece. In this work, the influence of flushing fluid on discharge delay time was selected to do further study. With a series of experiments, the average discharge delay time and Laue plot under each condition were obtained. As the result, it was known that higher flushing speed can make the discharge delay time increase. Furthermore, the computational fluid dynamics model was built and the corresponding simulation was finished for exploring the reason for the occurrence of this phenomenon. This relative analysis is useful to better understand the discharge conditions and at the same time, it can be helpful for improving the configuration of machining parameters in future works.

During the single pulse discharges in electrical discharge machining (EDM), the electrode materials are melted and evaporated. The vapor jets generated from the electrode surfaces influence the fluid flow inside the discharge gap as well as the melt pool dynamics. In this study, a multi-physics coupling simulation model based on FEM was built to solve the fluid flow inside the melt pool and discharge gap simultaneously. The mass flux from the melt pool surface was transferred to the boundary of the gap domain and the normal and shear stress generated by the fluid dynamics in the gap were applied to the melt pool surface. By this way, a more physics-based results on the melt pool dynamics can be obtained, which promotes the understanding of the gap phenomena in EDM.

Scraping, as a useful processing method, is widely used in the processing of obtaining high-precision sliding surfaces in industrial production. At the same time as scraping processing, it can also get small grooves that can be used as oil pockets on the sliding surface. In this study, in order to replace the scraping operation to process oil pockets, based on the electrochemical machining method using porous solid balls as electrolyte absorption materials, by controlling the moving trajectory of the porous solid ball and the power on/off of the circuit during ECM processing, some grooves seem like oil pockets of scraping are obtained on the workpiece surface.