Ultra-fast rotary ultrasonic micro-hole machining of silicon wafers: a comparative study between twist drill and diamond tools.

Theoretical and experimental investigations on phase difference in ultrasonic elliptical vibration cutting of tungsten alloys.

Microwave (MW) sintering offers a promising alternative to conventional heating in powder metallurgy, providing faster processing, lower energy consumption, and improved microstructural control. In the diamond tool industry—where cost-efficiency and competitiveness are critical—MW–hybrid sintering shows strong potential for producing segments designed for cutting and polishing natural stone and construction materials. This study investigates the effects of sintering temperature, dwell time, and green density on the densification and mechanical properties of metal matrix composite (MMC) segments containing diamond particles. MW sintering reduced the optimum sintering temperature by 90–170 °C when compared to conventional free sintering. Under optimal conditions (57% green density, 820 °C, 5 min dwell), segments achieved ~95% densification and mechanical properties comparable to hot-pressed (HP) samples. Although MW–hybrid sintered matrices exhibited slightly lower Young’s modulus (~15%) and Vickers hardness (~20%), their flexural strength and fracture toughness remained comparable to HP counterparts. Overall, MW hybrid sintering provides a cost-effective, energy-efficient, and scalable route for fabricating high-performance diamond tool segments, supporting both economic viability and sustainable, competitive manufacturing.

To prevent thermal explosions in octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystals during diamond turning, it is essential to manage the energy dissipation process at cutting hotspots located at the tip of the diamond tool. In this study, a comprehensive model is developed to analyze the friction-induced thermal safety of HMX crystals during diamond turning, incorporating both heat conduction and entropy generation mechanisms. The temperature distribution and the entropy generation at the hotspots are further validated through equivalent heat conduction experiments. The underlying cause of the friction hazard is identified from both temporal and spatial perspectives. The results demonstrate that there is an intrinsic relationship between entropy generation and hazardous energy: an increase in entropy generation generally corresponds to a decrease in the quality (i.e., chaos level) of the hazardous energy during the diamond turning process. Compared to temperature distribution, entropy generation offers a more effective and reliable indicator for safety evaluation in both time and space domains. Therefore, the integrated use of temperature distribution and entropy generation as safety criteria is of great significance in elucidating the ignition mechanism of friction hotspots in HMX crystal machining.

In single-point diamond turning of hard and brittle materials, the micro-grooves on the cutting edge of the tool, as an important feature of tool wear, are closely related to the structural parameters and wear behavior, having a significant impact on tool performance, lifespan, and workpiece surface integrity. Therefore, this study utilizes molecular dynamics simulations to construct diamond tools with V-shaped groove structures of varying parameters (width W and height H) and single-crystal γ-TiAl alloy cutting models, systematically analyzing the influence of the evolution of the tool's V-shaped structure on the cutting behavior of the single-crystal γ-TiAl alloy and tool wear. The results show that tool groove shape evolution affects cutting temperature/stress distribution, influencing cutting instability and tool wear. During cutting, the diamond tool bond length shortens, the bond angle distorts, the sp3 hybrid orbital damages, and crystal transforms to graphite. Micro-grooves increase cutting force fluctuation. Despite a notable rise in surface roughness with increasing groove parameters, the T2 tool (W = 1.4 nm, H = 1.4 nm) reduces workpiece surface roughness Sa by 7.66% vs traditional tools, effectively enhancing surface quality. Additionally, increasing the groove width W reduces the depth of the subsurface damage layer and inhibits the expansion of subsurface dislocations. Therefore, revealing the evolution mechanism of the tool groove shape is of great significance for achieving efficient processing of single-crystal γ-TiAl alloy and synergistically improving surface quality and tool lifespan.

Relevance. Modern ways of upgrading drilling tools are aimed at obtaining designs that improve the quality of well drilling. At the same time, the geometry of the core tool should contribute to an increase in the core yield and maintain its integrity. The existing serially produced drilling tool allows achieving high indicators of the well construction, solving the problems of opening and sampling in sections with difficult drilling conditions. Thus, the design of the drilling tool with end flushing ensures the penetration of the cleaning agent directly under its working end without contact with the core, which helps to preserve the obtained mining and geological information of the sample. The use of such a drilling tool is most relevant when sampling soft, heavily destroyed or loose rocks. Given the specified area of use, the main disadvantage of the design of the flushing system of the tool with end channels is the high probability of their sludge contamination with the onset of negative consequences that reduce the technical and economic indicators of drilling and the potential of the tool. Thus, eliminating any possibility of clogging of the end flushing channels contributes to the implementation of the full-fledged operation of the tool. The work analyzes the hydrodynamic processes occurring in the flushing system of the tool and in the bottomhole zone of the well, which made it possible to determine the causes of channel clogging. The presented modernization of the tool geometry was made in order to eliminate the identified causes and improve the circulation of the cleaning agent. Aim. To develop a design for a flushing system for a drill bit with end flushing, providing optimal parameters of pressure and flow rate of flushing fluid in order to prevent clogging of the end flushing channels. Objects. Hydrodynamic processes occurring in the flushing system of a core drilling tool with end flushing. Methods. Analytical method, computer modeling method. Results. The paper presents a method for modernizing the flushing system of a diamond tool with end flushing. By creating favorable conditions for the flow of the cleaning agent by the proposed method the authors have solved the problem of slagging of the front channels of the flushing system located in the end part of the crowns and improved the cleaning of the tool working surface. The presented design of the flushing system of the crown allows fully implementing the functions of the cleaning agent without loss of hydraulic energy, and thereby improving the quality of well drilling and core sampling in loose, soft, easily destructible rocks. The effect is achieved by eliminating the zones of hydraulic resistance that occur at the junction of the structural elements of the drill crown.

An insight into the origins of the cutting edge profile errors of the micro diamond tools: from a mechanical perspective

High-pressure driven lubricant infiltrated porous diamond for the preparation of self-lubricating diamond tools

Development of a high-precision polishing method for improving the cutting-edge sharpness of polycrystalline diamond tools

Frictional dynamics of tool-chip interactions in ultra-precision cutting of titanium alloy utilizing a PFPE-coated diamond tool

Mechanical behavior of material removal under various rake angle diamond tool ultra-precision cutting of titanium alloy

Objective: The objective of this study is to develop and analyze an Fe-Cu-Ni-Sn-WC-based metallic matrix with different additions of Boron Carbide (B4C), aiming at its application in the production of beads for diamond wires used in cutting ornamental stones. Theoretical Framework: The research is grounded in the field of powder metallurgy and composite materials, focusing on the effects of ceramic reinforcements such as B4C in metallic matrices. Theories on particle dispersion, interfacial bonding, and sintering behavior provide the basis for understanding the interactions between the metallic base and ceramic phases. Method: Five different compositions were prepared with B4C content of 2%, 4%, 5%, 8%, and 10%. The samples were produced by hot pressing at 800 °C and 34 MPa, resulting in rectangular segments. Characterizations were performed using Scanning Electron Microscopy (SEM) and Confocal Microscopy to evaluate microstructural features and surface topography. SEM was used to investigate particle distribution, morphology, and interface quality, while confocal microscopy assessed surface roughness and uniformity. Results and Discussion: The SEM analysis revealed variations in B4C dispersion and agglomeration across the samples, along with differences in interface quality and porosity. Confocal microscopy allowed the observation of surface irregularities, providing important insights into roughness patterns influenced by the B4C content. Research Implications: The findings contribute to improving the design and manufacturing of cutting tool components by identifying optimal B4C concentrations for better microstructural homogeneity and surface characteristics. These insights are relevant to the ornamental stone processing sector and advanced composite development. Originality/Value: This study presents a novel approach to optimizing metallic matrices for diamond tools using varying B4C content. The combined use of SEM and confocal microscopy provides a comprehensive evaluation of microstructure and surface properties, adding value to the field of powder metallurgy and materials engineering.

Abstract Variations in the diamond tool rake angle affect cutting forces, chip formation, subsurface damage, and stress distribution. Researchers have diverse opinions on the optimal rake angles for best performance, and there is a need for further understanding of the mechanisms involved in material removal employing various analysis techniques. This study investigates the effects of different diamond tool rake angles (ranging 0 to − 55°) on the nanometric cutting of single-crystal silicon using molecular dynamics (MD) simulation. Using Tersoff potential and various analysis techniques, the study examined atomic interactions, phase transformations, chip formation, and dislocation patterns. The results revealed that a − 45° rake angle produced the best surface quality with optimal dislocation distribution and minimal subsurface damage, and the 0° rake angle resulted in the least subsurface damage and highest material removal rate. Tools with rake angles of − 25°, − 35°, and − 55° showed increased phase transformation and subsurface damage. The research confirmed that the rake angle significantly influences the material removal mechanism and surface quality. The study highlights the importance of optimising rake angle to enhance surface quality, improve material removal efficiency, control subsurface damage, and enable ductile-regime machining. Graphical Abstract

Abstract Microtextured surfaces, such as those with groove, hole, or protrusion structures, are widely used in various industries for bonding dissimilar materials because of their anchor effect, which enhances adhesion and penetration with other materials. Although surfaces with grooves and protrusions are expected to show higher bonding strength, it is difficult to fabricate such hybrid structures using a material removal process or additive manufacturing. This study established a new burnishing method using a tool with preformed microgrooves at the tip to fabricate groove-with-protrusion structures on metal surfaces by plastic deformation. The tip of a ball-shaped polycrystalline diamond (PCD) tool was irradiated with a femtosecond pulsed laser to generate multiple trapezoid ten-micron scale grooves. Burnishing was then conducted on an oxygen-free copper surface to investigate the characteristics and mechanism of the burnishing-induced plastic deformation behaviors. The results showed that protrusions and grooves, which were several tens of micrometers in height and depth, were simultaneously produced along the tool path on the material surface. Tool sliding on the workpiece induced shear stress, which mainly triggered dislocation movement and plastic deformation enhancement. Cross-sectional observation revealed that grain elongation and refinement remarkably increased with the burnishing depth, indicating that the shear stress from burnishing produced refined grains that flowed and formed the protrusions. This research demonstrates the feasibility of a highly efficient method for simultaneously generating groove-with-protrusion structures with enhanced surface properties.

An analysis of the existing methods of sintering diamond-containing composites is presented. On the basis of mathematical modeling and experimental studies, the conditions of the laser liquid-phase sintering of diamond-containing composites under which they retain their strength are determined. The energy and technological parameters of the laser irradiation process are characterized, which determine the range of laser processing modes within which no oxidation and crack formation occur, and a high-quality composite with specified geometrical parameters is formed. It has been proven that composites consisting of synthetic diamond grains and a metal bond do not lose strength under the condition that the temperature during laser heating does not exceed 1600 °C and the exposure time is 0.3 s. Electron microscopy and X-ray diffractometry were used for experimental studies of the microstructure and phase composition of the sintered layers. A new design and manufacturing method for a drum-type abrasive tool with replaceable diamond inserts for grinding large-sized aircraft and shipbuilding products are proposed. Components of a laser technological complex for the implementation of the process of sintering the diamond-containing layer of the abrasive inserts of the drum have been developed.

The paper presents the results of theoretical and experimental studies of the effect of grinding wheel dressing methods on the height and pitch parameters of the roughness of the part surfaces treated. Analytical dependences are presented for calculating the roughness parameters of the surfaces of workpieces treated by grinding after various methods of dressing abrasive wheels, the reliability of which is confirmed by experimental studies. It is found out that in order to ensure surface roughness with a height parameter Ra of less than 0.4 microns, it is recommended to use an abrasive wheel dressing with a single-crystal diamond tool (diamond in a rim, diamond pencil). To ensure roughness with the parameter Ra in the range of 0.4 – 0.8 microns, it is recommended to dress the grinding wheel with a roller or a multi-crystal diamond pencil. Dressing the grinding wheels with carbide discs will ensure surface roughness after treatment with Ra parameter of more than 0.8 microns. It is found out that the radius of rounding of the tops of abrasive grains has a significant effect on the step parameters of the roughness of workpiece surfaces treated by grinding. At the same time, the average step value of the roughness profile irregularities along Sm mean line is 2-3 times greater than the average step value S of the local protrusions of the roughness profile. Therefore, the formation of fine irregularities of the surface with a given ratio of height and pitch parameters is possible by selecting the grain size of the grinding wheel, which affects the radius of rounding of the grain vertices. The paper presents scientifically based recommendations on the choice of methods for dressing abrasive tools and the conditions for maintenance of the roughness parameters of the workpiece surfaces processed by grinding wheel face.

Enhancing the wear resistance of polycrystalline diamond tools in Cf/SiC machining via ion implantation

Abstract This study focuses on the use of infrared nanosecond laser technology to prepare microgroove textures on the surface of polycrystalline diamond (PCD) tools, and systematically explores the effects of parameters such as laser power, scanning speed and defocus on the geometric characteristics of microgrooves. By constructing an experimental data set containing key processing parameters and microgroove morphology features, a machine learning model is introduced to model and predict the nonlinear relationship between complex parameters. The CatBoost model performs best, accurately describing the variation in depth and width of the groove, and the curvature of the fillet at the groove opening. Laser power has a significant positive correlation with microgroove depth and width, while defocus is a key factor affecting curvature, and there are complex interactive effects between parameters. Combining Gaussian process-based optimization and multi-objective genetic algorithm, the optimal laser parameter combination of microgroove depth and curvature is obtained, which provides a technical means to improve the friction reduction and wear resistance of microgroove texture tools in composite material processing

The study investigates the problem of modeling cutting-force components through response surface methodology and reports the results of an investigation into the impact of machining parameters on the cutting mechanics of polymer-matrix composites. The novelty of this study is the modeling of cutting forces and the determination of mathematical models of these forces. The models describe the values of forces as a function of the milling parameters. In addition, the cutting resistance of the composites was determined. The influence of the material and rake angle of individual tools on the cutting force components was also determined. Measurements of the main (tangential) cutting force showed that, using large rake angles for uncoated carbide tools, one could obtain maximum force values that were similar to those obtained with polycrystalline diamond tools with a small rake angle. The results of the analysis of the tangential component of cutting resistance showed that, regardless of the rake angle, the values range from 140 N to 180 N. An analysis of the feed component of cutting resistance showed that the maximum values of this force ranged from 46 N to 133 N. The results showed that the highest values of the feed component of cutting resistance occurred during the machining of polymer composites with carbon fibers and that they were most affected by feed per tooth. It was also shown that the force models determined during milling with diamond insert tools had the highest coefficient of determination in the range of 0.90-0.99. The cutting resistance analysis showed that the values tested are in the range of 3.8 N/mm2 to 15.5 N/mm2.

Long-term performance analysis of polycrystalline diamond (PCD) tools in the milling of aluminium alloy components in a manufacturing context