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Graphene has been shown to significantly enhance the mechanical properties and wear resistance of ceramic tools, thereby endowing them with superior cutting performance. However, as a two-dimensional carbon nanomaterial, the anisotropic nature of graphene can induce varying physical and mechanical properties in ceramic composites, which in turn can result in differing cutting performance and anti-friction and wear-resistant properties for graphene-reinforced ceramic tools. To elucidate the distinct cutting performances and wear characteristics influenced by graphene anisotropy, this study fabricates two types of graphene-reinforced ceramic tools with different graphene orientation distributions (perpendicular and parallel to the hot-pressing axis). The cutting performances and wear characteristics of these tools are then evaluated through continuous turning experiments on 40Cr hardened steel. It has been found that superior cutting performance is achieved when the orientation distribution of graphene in ceramic tools is perpendicular to the hot-pressing axis. Furthermore, this orientation is also optimal for achieving superior wear resistance in graphene-reinforced ceramic tools. The findings from this study could provide valuable insights for the design and fabrication of graphene-reinforced ceramic tools.

High-silicon cast steel exhibits good ductility and mechanical strength after microstructure transformation through an austempering heat treatment. The combination of these properties is outstanding in other steels, leading to emerging applications for high-silicon cast steel, such as in the railway sector. The Si content above 1.5% is a crucial factor for the formation of refined bainite and a dispersion of carbides in the matrix. This work involves the evaluation of the machinability of a steel alloy with 0.77% C and 1.77% Si using ceramic metal and ceramic tools. The alloy was cast, homogenized, austempered, and tempered. Subsequently, the high-silicon cast steel was characterized using scanning electron microscopy (SEM), hardness, tensile strength, and elongation. Machinability tests were conducted by turning and varying the cutting speed under dry cutting conditions with a constant feed rate. The analyzed output parameters were surface roughness, tool wear, and wear mechanisms. The increase in cutting speed directly influenced tool wear for all tools. The predominant wear mechanisms observed during the tests were abrasion and diffusion. The hard metal tool exhibited chipping on the cutting edge.

Nickel-based high-temperature alloys are widely used in various industries due to their excellent properties, but they face significant challenges in processing performance. Ceramic tools are ideal materials for processing nickel-based high-temperature alloys because of their high hardness. Dry intermittent turning of the nickel-based superalloy GH4169 was conducted in this paper, and the cutting performance of circular ceramic tools and rhombic ceramic tools were compared. Additionally, machine tool energy consumption, machined surface roughness, cutting temperature, ceramic tool life, and flank wear distance were measured. The optimal cutting parameters were selected by analyzing the experimental data. The research results showed that machine tool energy consumption increases as cutting speed and cutting distance increase, and it is also associated with tool geometry. Rhombic ceramic tools exhibit lower machine tool energy consumption, while circular ceramic tools perform better in terms of tool life. During the full life cycle of ceramic tools, the machine energy consumption of rhombic ceramic tools is 9.6% lower than that of round ceramic tools. The wear forms and wear mechanisms of ceramic tools were obtained by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). Adhesive wear, notch wear and diffusion wear are the wear mechanisms of round ceramic tools. Ceramic tools can also be worn and damaged due to impact and thermal stress. By analyzing the wear distance of the flank face, the optimal cutting parameters are determined as follows: cutting speed v c  = 110 m/min, feed rate f r  = 0.10 mm/r, and cutting depth a p  = 0.10 mm. Under the optimal parameters conditions, the tool life of 6160(R) is 50% and 12.5% longer than those of the other two round ceramic tools respectively.

Machining is an indispensable manufacturing process for a wide range of engineering materials, such as metals, ceramics, and composite materials, in which the tool wear is a serious problem, which affects not only the costs and productivity but also the quality of the machined components. Thus, the modification of the cutting tool surface by application of textures on their surfaces is proposed as a very promising method for improving tool life. Surface texturing is a relatively new surface engineering technology, where microscale or nanoscale surface textures are generated on the cutting tool through a variety of techniques in order to improve tribological properties of cutting tool surfaces by reducing the coefficient of friction and increasing wear resistance. In this paper, the studies carried out to date on the texturing of ceramic and superhard cutting tools have been reviewed. Furthermore, the most common methods for creating textures on the surfaces of different materials have been summarized. Moreover, the parameters that are generally used in surface texturing, which should be indicated in all future studies of textured cutting tools in order to have a better understanding of its effects in the cutting process, are described. In addition, this paper proposes a way in which to classify the texture surfaces used in the cutting tools according to their geometric parameters. This paper highlights the effect of ceramic and superhard textured cutting tools in improving the machining performance of difficult-to-cut materials, such as coefficient of friction, tool wear, cutting forces, cutting temperature, and machined workpiece roughness. Finally, a conclusion of the analyzed papers is given.

To address brittle cracks in ceramic tools, an exogenous precursor ceramic repair agent was developed and applied to Al O /TiC/NiMo composite ceramic tools, which were treated by a two-step heat treatment process (heating at 3 °C/min to 300 °C for 60 min, heating the sample at 5 °C/min to 500, 600, 700, 800, and 900 °C, holding each for 60 min). The crack healing mechanism and temperature dependency of the repair agent were investigated. Cutting performance, including surface roughness, cutting force, and tool life, was optimized using an L9(34) orthogonal design. The results show that at 900 °C, the repair agent decomposed to form SiOC (Silicon Oxycarbide) amorphous phase and TiB reinforced phase, filling the cracks and achieving atomic-level diffusion bonding. The flexural strength of the repaired sample recovered to 79.9% of the initial value (456.5 MPa), a 196.4% increase compared to the unrepaired sample. Optimal cutting parameters were found to be a cutting speed of 200 m/min, back draft of 0.1 mm, and feed of 0.1 mm/r. Under these conditions, surface roughness was 0.845 μm, cutting temperature was 258 °C, and stable tangential force was 70 N. The effective cutting distance of the repaired tool was increased from 1300 m to 1700 m. Wear was primarily abrasive and adhesive wear, and the SiOC phase formed by the repair agent helped to fill and repair the flank, thus extending tool life.

A new β-SiAlON ceramic tool with satisfactory cutting performance was prepared by microwave sintering. Effects of sintering additives and sintering process on mechanical properties and microstructure of the β-SiAlON ceramic tool were studied. Cutting performance of the tool was evaluated by high-speed milling Inconel718. The β-SiAlON ceramic tool with 5 wt% Y 2 O 3  + 0.5 wt% Yb 2 O 3 sintering additives possessed the homogeneous microstructure and best mechanical properties, but the transformation of plate-like grain to columnar grain was restrained as the content of Yb 2 O 3 exceeded 1 wt%. The β-SiAlON ceramic tool was prepared at 1600 °C with the holding time of 5 min. Compared with conventional sintering technologies, the holding time was reduced by more than 90%. The highest material removal volume was obtained at v c  = 800 m/min, a p  = 1 mm, and f z  = 0.05 mm/z, which was 5 times more than that of commercial coated tool. The main failure mechanisms of the tool were adhesive wear and cutting edge fracture.

Two kinds of α/β-SiAlON ceramic tools with different ratio of α-SiAlON to β-SiAlON (10α:90β, 40α:60β) were prepared via spark plasma sintering (SPS). The orthogonal and single-factor experiments were conducted to optimize the milling parameters of the tool. Also, the tool life, failure modes, and wear mechanisms of α/β-SiAlON ceramic tools were studied. The optimal milling parameters for the high-speed face-milling of Inconel 718 by SPS-sintered SiAlON ceramic tools were v c  = 800 m/min, f z  = 0.12 mm/z, and a p  = 1.5 mm. Life of the tool containing high α-SiAlON content (40α:60β) was twice that of the tool with lower content of α-SiAlON (10α:90β), and 2.7 times that of commercially available SiAlON ceramic tool. The SPS-sintered SiAlON ceramic tools displayed better wear resistance than that of a commercially available tool even under recommended cutting parameters of the commercial tool ( v c  = 1000 m/min, f z  = 0.08 mm/z, and a p  = 1.5 mm). The failure modes of SPS-sintered tools were dominated by the flaking of rake face, chipping of cutting edge, and flank wear. The primary wear mechanisms were adhesive, diffusive, and abrasive wear.

To address the poor thermal shock resistance and high brittleness of traditional ceramic tools, a novel Si3N4/Sc2W3O12 (SNS) composite ceramic material was developed via in situ synthesis using WO3 and Sc2O3 as precursors and consolidated by spark plasma sintering. Sc2W3O12 with negative thermal expansion was introduced to compensate for matrix shrinkage and modulate interfacial stress. The effects of varying Sc2W3O12 content on thermal expansion, residual stress, microstructure, and mechanical properties were systematically investigated. Among the compositions, SNS3 (12 wt.% Sc2W3O12) exhibited the best overall performance: relative density of 98.8 ± 0.2%, flexural strength of 712.4 ± 30 MPa, fracture toughness of 7.5 ± 0.3 MPa·m1/2, Vickers hardness of 16.3 ± 0.3 GPa, and an average thermal expansion coefficient of 2.81 × 10−6·K−1. The formation of a spherical chain-like Sc-W-O phase at the grain boundaries created a “hard core–soft shell” interface that enhanced crack resistance and stress buffering. Cutting tests showed that the SNS3 tool reduced workpiece surface roughness by 32.91% and achieved a cutting distance of 9500 m. These results validate the potential of this novel multiphase ceramic system as a promising candidate for high-performance and thermally stable ceramic cutting tools.

The machinability and wear reduction mechanism of self-repairing and self-lubricating ceramic tools sintered by vacuum hot-pressing method in the dry turning of 40Cr hardened steel was studied. By comparing the cutting performance and wear morphology of AT (Al2O3/TiC) ceramic tools under different cutting parameters, it was found that AT10B@5 (Al2O3/TiC/10 vol% TiB2/5 vol% h-BN@Al2O3) tool has a longer service life and better machining quality. Owing to the precipitation of solid lubricant during the cutting of AT10B@5 ceramic tool, the friction force during the cutting is reduced, thus decreasing the cutting force and cutting temperature of AT10B@5 ceramic tool during the cutting. The main cutting force decreased by 20.8%; the cutting temperature decreased by 22.2%; and the friction coefficient of front tool face decreased by 11.6% compared with AT tool. This effectively improved the surface quality of working parts, reduced the tool wear, increased the processing quality of work piece, and prolonged the tool life.

This work reflects the effects of tool tip temperature on flank wear of ceramic cutting tools during the turning of nickel alloy 718 (HRC 45). Two types of ceramic cutting inserts were used Al oxide (620) and mixed oxide (6050), during the turning operation under dry environmental conditions at various cutting speeds of 145 m/min, 230 m/min and 360 m/min respectively. The Al oxide inserts showed better results at cutting speed of 145 m/min and 230 m/min than mixed oxide. The worn out edges of inserts and micro structural properties were obtained by using SEM and tool makers microscope. The results were obtained after analyzing each test. The wear resistance of cutting inserts were affected by the tool tip temperature at the cutting zone.