Grinding Tool Research Articles

To the study of economic activities of the population of the Saka period in Central Kazakhstan (on the materials of traceological studies)

The Tasmola Culture of Central Kazakhstan, dated to the 8th–5th centuries BC, was discovered more than half a century ago by M.K. Kadyrbaev. He studied dozens of kurgans, on the materials of which he characterized the mortuary rites and funerary equipment of the new culture at a high professional level. On the basis of the materials from the burial sites, he for the first time considered the features of the economic activity of the population of the Saka period in Central Kazakhstan. Recent materials, including those obtained from the settlements, make it possible to largely extend the existing conclusions and assumptions of those years. At the settlement of Abylai, located in the territory of the Karaganda Region of the Republic of Kazakhstan, six seasons of archaeological excavations were carried out in 2016–2021. First results of the traceological analysis of stone tools from this site have already been published by the authors. In this paper, we report the results of the traceological study of a new series of stone tools from the Abylai settlement. In 2021, 254 stone objects were examined, functions of 202 of which were determined. As the analysis showed, 185 tools were used in various economic areas. The remaining 15 items were identified as kitchen utensils; there was also one mortar for grinding paints and one small altar (‘credence’), which is very often found in the burials of this culture. The 185 tools are divided into 5 classes, each of which belongs to a certain area of economic activity (ancient industries). Among those, 92 articles (49.73 % of the total number) are tools for the earthworks. Fifty articles (27.03 %) belong to the class of grinding tools. These are pestles and upper and lower grindstones, which were used for grinding plant products. Next 26 tools (14.05 %) were used in the processing of skins (tanning industry). Thirteen tools (7.03 %) were used in metalworking, including the work with iron products. Four tools (2.16 %) were used to process bone and wood. Among the results obtained, of a particular importance are the finds of numerous hoes and grating tools, as well as tools for metalworking, on which traces of iron surface are clearly identified. In addition to the whetstones, used for dressing knives and other iron objects, the new series of tools contains stone anvils, on the working surface of which some iron scale preserves.

Research on Adaptive Control of Grinding Force for Carbide Indexable Inserts Grinding Process Based on Spindle Motor Power

The grinding force is the most sensitive physical measure of reaction loads in the grinding process. To enhance surface quality and assure high efficiency and stability of the grinding process, it is essential to accomplish adaptive control of the grinding force. This paper suggests a grinding force adaptive control system based on spindle motor power feedback, considering the process–machine interaction. The spindle motor power is utilized as a proxy for the grinding force because of the mapping relationship between the two variables. The machine tool’s feed rate is automatically modified to achieve adaptive control of the grinding force, after assessing the discrepancy between the collected spindle motor power and the preset power. Finally, a cemented carbide tool grinding experiment was performed on a 2MZK7150 CNC tool grinder. During the experiment, the grinding force was precisely controlled between 80 and 100 N, ensuring machining quality and increasing machining efficiency. The experimental results show that the adaptive control system can meet the high-efficiency and high-quality machining requirements of cemented carbide rotary blades.

Simulation and experimental research of tool path planning on profile and surface generation of aspherical-cylindrical lens array by ultra-precision envelope grinding

Profile accuracy and surface quality of microstructural array mold generated by ultra-precision machining are the premise of precision glass molding technology. Most optical applications of microstructural array mold need to obtain microstructures with sub-micron profile accuracy and nanoscale surface roughness. However, the structural characteristics of grinding wheel and array leads to the complexities of surface generation in envelope grinding. Experimental verification is time-consuming and laborious. In this paper, a multi-scale model is proposed to predict the surface topography of micro-aspherical-cylindrical structural array (MACSA) mold ground by different tool paths. Firstly, the ultrathin grinding wheel is reconstructed by considering the distribution characteristics of abrasive grains and the complex wheel profile. In this process, the grain distribution characteristics of the reconstructed grinding wheel are obtained by using the Johnson transformation the inverse Johnson transformation method. Then, a comprehensive model is established to understand the mechanism of the generation of the MACSA surface, which considers the wheel topography, the kinematics model of abrasive grains and the complex geometric conditions between tool and local surface profile in envelope grinding. The surface morphologies of MACSA obtained by simulation and experiment are coincident with each other very well. The simulation model is further verified by comparing the power spectral density (PSD) of the experimental and simulated surfaces. Based on the simulation and the experimental results, the effect of three tool path planning methods (constant step, constant arc length and constant scallop-height) on surface uniformity and profile accuracy is investigated to obtain a more uniform microstructural surface.

Probabilistic Aspects of Modeling and Analysis of Grinding Wheel Wear.

In this article, the methodology of using probabilistic models of the grinding tool wear process is presented. Probabilistic modeling with empirical data allowed determining the values of other important process features. Among them, the distribution of active grains lifetime or distribution of cumulative attritious wear of the grinding grain apex could be distinguished. The results of modeling and wear analysis of grinding wheels as well as experimental results on peripheral grinding with zoned grinding wheels are presented. The analyzed grinding wheels consisted of three layers: two identical external layers with conventional structure and one internal layer containing the addition of abrasive aggregates. The external layers were profiled by chamfering the edges. As a result, their nominal surfaces were conical. The internal layer had a cylindrical shape and was designed for smoothing the surface after machining with external part. The tools were designed to increase the grinding efficiency and hence a good quality of machined surfaces could be acquired. For the experimental tests, the Ti6Al4V titanium alloy was used. It was found that the change in the shape and position of the grinding zone, as a result of volumetric wheel wear, caused a significant change in fracturing intensity. In the case of multilayer grinding tools, the wear process depends on the physical properties of each layer and their participation during machining of the workpiece. The presented methodology could be applied to a study on the machining process stages, which concerns temporary states and their variability according to the machining time.This makes it possible to reduce the cost of developing new tools dedicated to specific applications.

Evolution of Electroplated Cubic Boron Nitride Tool Surface Texture Parameters During Point Grinding

Abstract Point grinding is an abrasive machining process that utilizes small diameter superabrasive single-layer grinding tools for accurate machining of complex 3D geometries. Due to the small nature of these tools, high wear-rates and uneven wear around the tool circumference present a challenge for their successful application for the finish machining of metallic components. It is, therefore, essential to monitor the surface condition of the point grinding tools, to ensure their safe and reliable operation. In this investigation, the 3D topography evolution of single-layer B126 cubic boron nitride (cBN) point grinding tools was characterized using focus-variation imaging. Given the wealth of information obtained using this method, a decision-matrix methodology was used to identify the most important parameters for monitoring the wear condition of the point grinding tools. Grinding trials were also performed with fixed cutting parameters and varied cutting durations up to 520 mm3 of material removed to assess the evolution of the point grinding tool surfaces over time as a result of wear during grinding of hardened D2 tool steel. The best criteria for the characterization of the surface texture of electroplated cBN point grinding tool surfaces were identified to be the average surface height (Sa), skewness (Ssk), root mean square gradient (Sdq), reduced peak height (Spk), peak material volume (Vmp), and developed interfacial area ratio (Sdr). These parameters performed best for direct measurement of point grinding tool surfaces, paving the way for the application of the imaging technique under manufacturing conditions as an on-machine monitoring method for performance assessment.

Processing it all: Starch residues on Jomon Period ground stone from southern Hokkaido, Japan

For the Jomon Period, ground stone technology related to processing activities, such as handstones and querns, are commonly associated with plant foods. In many cases, these tools are considered to be an indicator for the consumption of tree nuts. In this study, ground stone artifacts from 15 sites across southern Hokkaido were analyzed for starchy residues to examine the relationship between grinding tools and economic plant taxa in Jomon daily practices. Overall, 24 of the 76 artifacts examined here had observable starch grains, meaning a large percentage of tools did not appear to have been in contact with starchy plants. The starch types commonly found in underground storage organs (USOs) were the most prominent component of the observed grains, indicating the use of yams, lilies, and other roots or tubers. The evidence for Poaceae grasses, legumes, and nuts is less clear, but present alongside the USO starch granules. These results suggest that grinding implements were not limited to processing plant foods, and would not have been restricted to specific resources, such as nuts.

Data-driven bending fatigue life forecasting and optimization via grinding Top-Rem tool parameters for spiral bevel gears

To establish a bridge between grinding tool parameters and loaded tooth fatigue life, an innovative data-driven root flank bending fatigue life forecasting and optimization via Top-Rem tool parameters was proposed for grinding spiral bevel gears. The recent machine settings modification is extended into grinding Top-Rem tool parameters modification in case that geometric accuracy and root bending fatigue life are integrated into a collaborative optimization. The proposed Top-Rem modification includes three key steps: (I) arc-shaped blade, (II) top part, and (III) top fillet part. Then, while root bending stress is determined by using finite element method (FEM)-based simulated loaded tooth contact analysis (SLTCA), data-driven fatigue life forecasting is developed by correlating with the multiaxial fatigue damage model based assessment. Moreover, data-driven bending fatigue life optimization model is established by using Top-Rem tool parameters modification, where the important constraints in target flank determination includes: (i) root overcutting, (ii) geometric accuracy, and, (iii) fatigue life. For high accuracy and efficiency, two different strategies are proposed: (i) the different parameters modification types; and, (ii) sensitivity analysis of grinding Top-Rem tool parameters. Finally, proposed method can verify that bending fatigue life can be significantly improved by modifying the key Top-Rem tool parameters in early stage of the whole life product development for spiral bevel gears.

Cutting edge preparation with elastic bonded diamond grinding wheels: Influence of the interaction of metalworking fluid and grinding wheel on the grinding wheel properties and preparation result

The cutting edge preparation with elastic bonded superabrasive grinding wheels enables the accurate manufacture of customized cutting edges. This process necessitates highest accuracies of the machine and the kinematics. Up to now, no systematic investigations on the interaction of the metalworking fluid and the grinding wheel were done; those could alter the properties of the grinding wheel, and as a consequence the result of cutting edge preparation. The influence of this interaction on cutting edge preparation is investigated in this study using two different experimental setups. One setup where the grinding wheels interacted with the metalworking fluid in an aging chamber to speed up the aging process and one setup directly in a tool grinding machine, in which the grinding wheels were also applied for cutting edge preparation at different stages of aging. In the aging chamber, the interaction takes place under elevated metalworking fluid temperatures to accelerate possible interaction effects. The results revealed an increase in the diameter, width and weight of the grinding wheels and a reduction in hardness. These changes were more pronounced under the elevated temperatures in the aging chamber. This in turn resulted in a significant alteration in the geometry of the prepared cutting edges, which was not observed when the grinding wheels interacted with the metalworking fluid in the tool grinding machine. As a general result, to keep the properties of the grinding wheels approximately constant, continuous dressing cycles should be carried out. In addition, the grinding wheels should be stored in dry conditions when not using them. In this way, specific cutting edge geometries can be manufactured reproducibly.

Study of grinding and polishing tools in automated processing of curved stone

The grinding and polishing of curved stone involve many steps, limiting the process's efficiency. This study proposes a one-step grinding and polishing process to simplify the process and achieve efficient machining. It is achieved by developing the grinding and polishing tools and realizing the entire process on the robotic processing platform, and the tool design is based on the surface roughness of the machined workpiece. The grinding tool is made by selecting the appropriate glue to achieve the connection from carving to polishing. Similarly, the polishing tool is made by selecting the appropriate gel compound system to achieve a high glossiness curved stone surface. The results show that the grinding tool made of epoxy resin YT-CC301 can reduce the curved stone's roughness from 16.281 µm to below 400 nm, and the connection from carving to polishing can be realized by one step. The polishing tool made of sodium alginate and carboxylated chitosan gel compound system or sodium alginate and sodium carboxymethyl cellulose gel compound system can polish the surface of the ground curved stone to the roughness of less than 15 nm, and the surface glossiness can reach more than 120. Therefore, a single step of grinding and polishing of curved stone is achieved.

Top-Rem grinding tool modification considering loaded edge contact for spiral bevel gears

Focusing on the collaborative manufacturing requiring meshing interface physical performances, an innovative Top-Rem grinding tool modification considering loaded edge contact is proposed for spiral bevel gears. Accurate Top-Rem grinding tool parameters can instead of machine-tool settings and their impact in the sophisticated flank topography correction technique. At first, the whole Top-Rem tool modification includes: i) arc-shaped blade part; ii) Top-Rem part; iii) top fillet part. Then, grinding tool modification model considering both loaded contact and geometric accuracy is established. Where, three important constraint conditions were taken into accounts: i) geometric boundary considering loaded edge contact, ii) root overcutting, and iii) flank geometric accuracy. Moreover, two kinds of optimization strategies are proposed to improve the accuracy and efficiency of the whole modification: i) two types of modification by the different tool modification parameters; ii) sensitivity analysis with respect to ease-off for optimization operation of the unknown variables. Finally, the given instances can verify that it can get accurate and effective loaded contact performance optimization in early stage of full life cycle product development.

Surface Modification of Alumina Particles to Enhance Bonding Properties with Rubber and Resin in Grinding Tools

The mechanical properties of grinding-tools relies highly on adhesion between the abrasive particles and the bonding phase, generally composed of organic rubber or resin materials. The surface modification of abrasive particles represents an industrial alternative to improve the connection with the bonding phase material. However, increasing the roughness of abrasive particles is a challenging process because of their high chemical stability. In the present study, three different approaches are investigated to modify the surface of industrially used alumina abrasive particles. Chemical erosion under harsh acidic and alkaline conditions, and hydrothermal deposition of aluminium-based coatings were used for the surface modification of the abrasive particles. The chemical stability of alumina particles was demonstrated by the chemical etching while the succesufull surface deposition of AlOOH crystals modified the apparent roughness of the processed powder particles. Morphological changes after each treatment were studied by scanning electron microscopy and the phase composition was confirmed by X-ray diffraction.

Prospects for the development of deep-feed grinding of gas turbine engine parts using highly porous cubic boron nitride wheels

The technologies of deep grinding of gas turbine engine parts are analyzed. The features of a grinding tool made of traditional abrasives and superhard materials are revealed. Ways to improve the effectiveness of this treatment using highly porous cubic boron nitride wheels are proposed. Keywords; deep-feed grinding, gas turbine engine, multi-coordinate grinding center, nickel heat-resistant alloy, highly porous cubic boron nitride wheel. d_i_volkov@rsatu.ru, boris_tsvetkov@mail.ru

Process improvement of hardening furnace (mapping) in tool industry – A case study

The aim of this paper is to identify the temperature variation within a furnace and also find the variation of hardness in a tool after quenching. The paper takes a case study approach, demonstrating how theory has been used in practise and using one way ANOVA to estimate the optimum number of tool grinding required before inspection. The case study was carried out at a leading hand tool manufacturer in India. Lean Six Sigma (LSS) is found to work very well in the tool manufacturing industry for improvement the process. The LSS strategy for manufacturing industries shows how merging statistical and analytical tools helps to improve process efficiency. Our primary constraint was the measurement instrument, which was a thermal laser gun that could only correctly measure one metre values. This study shows an application of one-way ANOVA and lean/six-sigma concepts to process improvement. The major goal of this study is to show how combining Lean concepts/techniques with one-way ANOVA and Six-Sigma methodology can help solve problems faster.

Stress state of the grinding tool loaded with tangential force

Purpose. Determining the interaction mechanism of discrete grains through material that binds them in a tool for abrasive material processing in the case of its loading with a tangentially directed cutting force. Methodology. Development and analytical solution to a mathematical model formulated on the basis of static equilibrium of an abrasive grain as a system element of tool grains bound with a material with excellent mechanical characteristics. Findings. A mathematical model has been developed and an algorithm has been formulated to analytically determine the stress-strain state parameters of a tool for abrasive processing of materials, which is loaded with a discrete cutting force, tangential to its working surface. The nature of the dependence of stresses and deformations on mechanical parameters, the quantity of grains and the material binding them in an abrasive tool, loaded with a unit tangential force, has been determined. Originality. The loading of the extreme grains leads to greater displacements, tangents of the shear angles of the material binding the grains. They decrease with increasing quantity of grain rows in the tool or with increasing quantity of grains to the nearest tool edge. Practical value. The distribution of interaction forces of grains and stresses in the material binding them has been determined. The found distribution allows one in the process of developing the tool and technology, in which it is involved, to comprehensively assess the influence of tangential load value of the tool working grain on its stress state and the material containing the grains. The determined stress state makes it possible to predict the number of loading cycles until the simultaneous rational wear of the grain and the destruction of that part of the material that contains it. The linear formulation of the problem makes it possible to take into account the mutual influence of the tangential loads of several grains on the stress-strain state of the tool as a whole.

Features of Machine Grinding of Surfaces with a Flap Wheel

In order to obtain the necessary shape of long panels and sheaths, the aircraft industry successfully uses a complex technology of shaping. Grinding, as an operation in a complex technological process, is provided after the operation of shot-peen forming before hardening. It is designed to ensure that the roughness and final aerodynamic shape of the surface meet the requirements established by the drawing of the part. To implement this technology, a special installation UDF-4 (shot-impact forming unit) was designed and manufactured at the Irkutsk National Research Technical University. The version of this installation was equipped with a CNC system and a revolver stripping head with 4-flap wheels. The possibility of choosing the necessary flap wheels in the process of grinding, depending on the curvature and width of the treated surface, significantly expanded the technological capabilities of the installation. The elastic abrasive flap wheels of a straight profile used in production have proven themselves well both in terms of grinding performance and tool durability. However, practice has shown that due to the complex impact of abrasive petals during contact with the treated surface, a special zone of uneven impact along the length of the contact of the petals is formed during grinding. The results of experimental studies have shown that the roughness of the treated surface is significantly improved when the direction of movement of the flap wheels feed in the contact zone is changed from oncoming to passing. The paper presents experimental data on studies of changes in surface roughness in the contact zone with the abrasive flap wheels during grinding, depending on the processing modes, as well as the results of an experimental study of the quality of the treated surface with counter and passing feed.

Geometrical process design during continuous generating grinding of cutting tools

Modern cutting tools like end mills, drilling tools, and reamers underlie high requirements regarding geometrical accuracy, cutting edge quality, and production costs. However, the potential for process optimization is limited due to the process kinematics during grinding. Consequently, a novel tool grinding process for the manufacture of cutting tools has been developed recently at the Institute for Production Engineering and Machine Tools (IFW). This continuous generating grinding process allows the simultaneous production of all flutes and circumferential flank faces of rotational symmetrical cutting tools. The present paper focuses on the geometrical process design and develops a method to determine the necessary basic rack and process parameters in order to create a desired cutting edge geometry by continuous generating grinding. The developed method can define all parameters with an accuracy of up to 5 µm and 0.2° within a simulation in five iteration steps and allows not only the quantitative design of the cutting tool geometry but a qualitative modification of the flute geometry as well. Subsequently performed grinding tests showed that the presented method allows the design of grinding worms for continuous generating grinding of cutting tools and enables the successful implementation of these processes.

An Investigation on the Total Thickness Variation Control and Optimization in the Wafer Backside Grinding Process.

The wafer backside grinding process has been a crucial technology to realize multi-layer stacking and chip performance improvement in the three dimension integrated circuits (3D IC) manufacturing. The total thickness variation (TTV) control is the bottleneck in the advanced process. However, the quantitative analysis theory model and adjustment strategy for TTV control are not currently available. This paper developed a comprehensive simulation model based on the optimized grinding tool configuration, and several typical TTV shapes were obtained. The relationship between the TTV feature components and the spindle posture was established. The linear superposition effect of TTV feature components and a new formation mechanism of TTV shape were revealed. It illustrated that the couple variation between the two TTV feature components could not be eliminated completely. To achieve the desired wafer thickness uniformity through a concise spindle posture adjustment operation, an effective strategy for TTV control was proposed. The experiments on TTV optimization were carried out, through which the developed model and TTV control strategy were verified to play a significant role in wafer thickness uniformity improvement. This work revealed a new insight into the fine control method to the TTV optimization, and provided a guidance for high-end grinding tool and advanced thinning process development.

Optimization of hydrodynamic properties of structured grinding wheels based on combinatorial bionics

Undesirable hydrodynamic properties are inevitable in the traditional grinding process, which often provides a harsher lubrication environment. This paper introduces combinatorial bionics to optimize the hydrodynamic properties of grinding tools innovatively. Two bionic prototypes (phyllotaxis arrangement and fish scale) with special hydrodynamic properties are organically integrated to help design a combinatorial bionic grinding wheel (CBGW). The CBGW can more effectively inhibit the adverse effects of air turbulence on the grinding process and maintain a higher useful flow rate with a maximum improvement rate of 290.47%. This study enhances the effectiveness of grinding fluids from the perspective of grinding wheel structure and provides an excellent tribological basis for green and high-efficiency grinding.

Influence of the powder metallurgy route on the mechanical properties of Cu–Cr–diamond composites

Metal-bonded grinding tools are commonly based on copper as bond material and possess low porosity. The powder metallurgic fabrication and the applied process parameters have a high influence on the mechanical properties of these grinding layers. In this study, Cu–diamond composites are fabricated through Field Assisted Sintering Technology with a variation of holding time, temperature, pressure, and chromium powder particle size. The addition of chromium to these composites can ensure a higher adhesion of the diamonds through carbide formation within the interface of the diamonds and the copper bonding matrix. The coating of diamond with chromium-carbide is mainly controlled by the chromium powder particle size, which leads to a higher critical bond strength with decreasing particle size. Maximum critical bond strength of 463 N/mm2 is reached using chromium with an average particle size of 10 µm. Increasing holding time decreases porosity and increases the critical bond strength of the composites. An increase of sintering temperature from 900 to 1040 °C leads to a decrease of porosity due to local melting of the copper. The interlocking of diamonds due to their high concentration of 50 vol% within the composites results in a relatively high porosity above 7%.Article HighlightsModelling of the influence of sintering temperature, sintering time and chromium particle size on the critical bond strengthAddition of chromium results in an in-situ formed carbide-layer when sintering above a temperature of 900 °CSmaller chromium particle sizes significant increase the mechanical stability of CuCr–diamond composites

Use-wear analysis of grinding tools and the exploration of plant processing in the Neolithic of Europe: State of the art and perspectives

Grinding and pounding implements are among the most widespread and most informative artefacts when it comes to addressing questions related to plant exploitation, especially in the field of food preparation practices. While use-wear analysis using optical microscopy (stereomicroscope and metallographic microscope, quantification using rugosimetry, confocal microscopy and 3D analysis combined with GIS modelling) and microresidues analysis (phytoliths, starch grains, palynomorphs) were considered innovative fields of research at the start of the 2000′s, they are now routinely and effectively applied in combination. Functional analysis of grinding tools from Late Mesolithic and Neolithic contexts in Europe now provides a general overview of the diversity of plants processed and of the techniques involved in their treatment prior to food preparation. The grinding of cereals has been shown to have predominated, but legumes, nuts and grass plants also played a major role. Nonetheless, depending on the region and cultural background, different types of grinding systems were employed, suggesting a strong link with varied food habits throughout the continent. After presenting an overview of our knowledge of plant transformation for food preparation, we look at challenging new issues for future research, most of which are centred on methodological improvements.