![]() It was revealed that burrs and chippings appear when the angle between the chip flow direction and the groove edge is less than a critical value. These large burrs and chippings were found to be induced by large slippages that are unique to amorphous alloys. Large burrs and chippings were formed when cutting with a tapered square tool and a tilted triangle tool. Microgrooving experiments were conducted with different undeformed chip geometries using three types of cutting tools to observe burr formation processes. In the present study, the burr formation process of amorphous Ni-P is defined and a three-dimensional cutting model using energy method is proposed to predict and minimize burrs and chippings. The formation mechanisms of burrs and chippings have not yet been revealed precisely in the cutting processes of amorphous alloys, because their cutting behavior is more complex and less discussed in existing researches than that of crystalline metals. However, burrs and chippings always form and are detrimental especially when fabricating micropatterns. Ultra-precision cutting is preferred to be used to machine the mold material for high precision in a large workpiece. Chatter-free and high productivity cutting conditions are determined through optimal parameter selection employing stability maps generated for each configuration.Īmorphous nickel phosphorus (Ni-P) alloy is a suitable mold material for fabricating micropatterns on optical elements for enhancing their performances. The stability model is formulated for two configurations of the parallel turning operation in frequency and time domains, and verified experimentally. workpiece and cutters, in addition to insert's geometry are accounted for. In order to tackle this problem, a multi-dimensional model for chatter stability analysis of parallel turning operation is presented where the effects of components' dynamics, i.e. In practice, however, ensuring a stable parallel turning of a flexible workpiece is approached by the costly process of trial and error. On the other hand, stability of flexible part turning can be increased significantly if the process parameters are selected properly. On one hand, chatter could be a fatal threat to the productivity and part quality in simultaneous turning operations of slender and flexible workpieces. Simultaneous turning with extra cutting edges increases the material removal rate (MRR), and thus the productivity of the process. Therefore, W/O nanoemulsion could be an alternative to water based dielectric in high-speed compound sinking machining applications. Experimental results demonstrate that compared with water based dielectric, machining with W/O nanoemulsion can obtain higher MRR, lower REWR, and better surface quality. Moreover, the characteristics of machined surface are investigated using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and micro hardness analysis. The influences of electrode polarity, peak current, and pulse duration on the material removal rate (MRR) and relative electrode wear rate (REWR) are studied. The performance of the compound machining using the proposed W/O nanoemulsion is investigated systemically by comparing with that using the traditional water based dielectric. The compound machining is the combination of arc machining and electric discharge machining (EDM). This study proposes a novel water in oil (W/O) nanoemulsion dielectric for use in high-speed compound sinking machining. SACE scanning experiments were conducted on ZrO 2 ceramics using the proposed tool electrode and found that it significantly improved machining efficiency and accuracy. Therefore, a cylindrical notched tool electrode with an increased number of sharp edges to improve discharge constraint is proposed in the SACE process. It is believed that the sharp square edge of the tool-electrode end is conducive to the end discharges by large. In a set of exploratory SACE experiments, it was found that a large percentage of discharges occur at the end of the tool electrode under certain conditions. However, the sidewall of the SACE tends to generate spark discharges, which not only waste energy but also affect machining accuracy. SACE (spark assisted chemical engraving) is an advanced technology for machining ZrO 2 ceramics that has also been used successfully in glass machining. However, the mechanical properties of ZrO 2 ceramics, such as brittleness, high hardness, and high temperature resilience, make it challenging to machine. Zirconium dioxide (ZrO 2) is a ceramic material used in a wide range of applications.
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