End Mill Cutter Research Articles

Prediction of Delamination Defects in Drilling of Carbon Fiber Reinforced Polymers Using a Regression-Based Approach

Carbon fiber-reinforced polymer (CFRP) structures have been increasingly used in various aerospace sectors due to their outstanding mechanical properties in recent years. However, the poor machinability of CFRP plates, combined with the inhomogeneous behavior of fibers, poses a challenge for manufacturers and researchers to define the critical factors and conditions necessary to ensure the quality of holes in CFRP structures. This study aims to analyze the effect of drilling parameters on CFRP delamination and to predict hole quality using a regression-based approach. The design of the experiment (DOE) was conducted using Taguchi’s L9 3-level orthogonal array. The input drilling variables included the feed rate, spindle speed, and three different drill types. A regression-based model using partial least squares (PLS) was developed to predict delamination defects during the drilling of CFRP plates. The PLS model demonstrated high accuracy in predicting delamination defects, with a Mean Squared Error (MSE) of 0.0045, corresponding to an accuracy of approximately 99.6%, enabling the rapid estimation of delamination. The model’s predictions were closely aligned with the experimental results, although some deviations were observed due to tool inefficiencies, particularly with end mill cutters. These findings offer valuable insights for researchers and practitioners, enhancing the understanding of delamination in CFRPs and identifying areas for further investigation.

Analysis and optimization of machining parameters of AZ91 alloy nanocomposite with the Influences of nano ZrO2 through vacuum diecast process

The magnesium alloy composite is a vital material for automotive applications due to its features like high stiffness, superior damping resistance, high strength, and lightweight. Here, the motto of research is to establish the AZ91 alloy nanocomposite with the exposures of 0, 1, 3, and 5 volume percentages (vol%) of nano zirconium dioxide (ZrO2) particles (50nm) through fluid stir metallurgy route associated with 1x105 Pa vacuum die cast process. Exposures on structural morphology, hardness, and impact toughness of composite are analyzed and identified as the nano AZ91 alloy composite enclosed with 5vol% is homogenous particle dispersion, enhanced hardness (97.6HV), and optimum toughness of 21.2J/mm2. However, composite faces machining difficulties due to the hard abrasive particles with higher hardness, resulting in tool wear. This experiment predicts the optimum mill parameters during the end mill operation of magnesium alloy nanocomposite (AZ91/5vol%) by using a tungsten carbide coated end mill cutter to attain the maximum metal removal rate with low surface roughness and tool wear analyzed via the general linear model (GLM) ANOVA approach. The input conditions for end milling operation vary, like feed rate (0.1 -0.4mm/rev), depth of cut (0.05 -0.2mm), and spindle speed (250-1000rpm). During the ANOVA GLM approach, the L16 design experiment is fixed for further interaction analysis. The results predicted by the depth to cut and feed rate were dominant and played a major role in deciding the tool wear, surface roughness, and MRR.

Wear Mechanism of an AlCrN-Coated Solid Carbide Endmill Cutter and Machined Surface Quality under Eco-Friendly Settings during Open Slot Milling of Tempered JIS SKD11 Steel

In the die and mold industry, tempered JIS SKD11 steel is selected to manufacture cold-forming dies that require an optimum balance of toughness, strength, and wear resistance. Therefore, the machinability of tempered JIS SKD11 in the milling machining process is challenging. The use of eco-friendly machining settings is intended to diminish tool wear and enhance the quality of the machined surface as well as the accuracy of the machined components. Adapting to the aforementioned factors for cold-forming dies is a pivotal issue. In this study, the machinability of tempered JIS SKD11 steel was analyzed under dry, MQL, cryogenic cooling with liquid nitrogen (LN2), and liquid carbon dioxide (LCO2) machining settings during open slot milling operations with varying input parameters, including cutting speeds and cutting feeds. An in-depth evaluation of output responses, including tool wear, surface roughness, cutting temperature in the cutting zone, and microhardness of the machined surface, was also conducted. The findings unveiled that the flank wear of the cutters and surface roughness of the machined surfaces obtained minimum values of 0.22 mm and 0.197 µm, respectively, during open slot milling operations at a cutting speed of 100 m/min and a cutting feed of 204 mm/min under cryogenic cooling with liquid carbon dioxide (LCO2). The findings from this study suggest that employing cryogenic cooling with LCO2 could serve as a viable substitute for dry, MQL, and cryogenic cooling with LN2 methods to enhance the machinability of hardened JIS SKD11 steel.

Damage critical transformation mechanisms in milling nickel-based superalloy honeycomb composites using different tool structures

Nickel-based superalloy honeycomb composite (NBSHC) has been developed into an indispensable material for aerospace and defense industries due to light weight, high temperature resistance and extremely high specific strength. Nevertheless, NBSHC is particularly difficult to machine, combing superalloy with thin-walled structure properties, and is prone to damage such as burr, tearing and core deformation. To realize the efficient and low-damage processing of NBSHC, the different tool structures were used during the milling NBSHC experiments under ice-freeing conditions. The material removal mechanisms of different cutters were revealed based on the micro and macro view, and verified by the experiment results. Then, the cutting force and damage behavior of different tools under different parameters during milling NBSHC process were analyzed. For the first time, the damages critical transformation mechanisms during milling NBSHC process were summarized based on above investigations. Results showed that: Since the contact area between saw blade or disc cutters and NBSHC workpiece was a surface, and the in-plane force was small. The qualities of NBSHC machined by saw blade and disc cutters were excellent. Due to the large in-plane force, discontinuity cutting and tearing from removed material, the quality of NBSHC machined by end-milling cutter was extremely terrible. Large cutting force, large contact volume, frequent impacts induced by discontinuity cutting and tearing from the removed material sharply increased the plastic deformation, thus deteriorating the quality of NBSHC and contributing to the transformation of slight damages into severe damages. This work provided significant theories and guidelines for efficient and low-damage machining of NBSHC in aerospace and defense fields.

Enhancing Turbine Blade Manufacturing through MEMS-Based Milling Monitoring

Manufacturing steam turbine blades with intricate shapes poses a substantial challenge. These blades significantly impact turbine efficiency, reliability, and productivity. Their precise formation through milling processes demands vigilant monitoring, especially concerning the cutting tool’s condition, which is responsible for shaping the blade profiles and ensuring high-quality outcomes. Direct tool monitoring, however, disrupts productivity, prompting the need for an indirect Tool Condition Monitoring (TCM) system. Such a system becomes essential for detecting tool wear and damage early, ensuring dimensional accuracy and surface smoothness. This experiment monitors tool conditions by analyzing vibrations generated by an endmill cutter while machining martensitic stainless steel (MSS) AISI 420. The setup employs a cost-effective MEMS vibration sensor, the ADXL 345, and Raspberry Pi for real-time online TCM functionality as the signal processor. This study delves into the sensor’s ability to capture vibrations representing actual tool conditions, focusing on the affordability and effectiveness of MEMS-based monitoring. The successful real-time implementation of MEMS-based monitoring could be an easily accessible gateway for manufacturing industries to embrace cloud-based monitoring systems, aligning with current technological trends. This research aims to underscore the viability and potential adoption of affordable MEMS sensors for comprehensive tool condition monitoring, offering a seamless transition toward cloud-integrated monitoring systems for manufacturing industries.

Development of an EN8 Steel Stepped Rotor by a Novel Engraving Milling Technique.

The rotor or impeller is a rotational and key part of a pump and compressor. This article presents the detailed development process of a rotor of small size constructed from an EN8 steel cylindrical blank using a novel technique based on a computer numerical control engraving milling machine (CNC-EMM) equipped with a 4 mm tungsten carbide end mill cutter. We fabricated a total of twenty-eight stepped rotors following the Box-Behnken Design (BBD) DoE technique at fourteen distinct combinations of CNC-EMM variable parameters, namely rotational speed, feed, and plunge feed. Average roughness 'Ra', an important surface quality indicator, has been considered and presented in this article, as a quality measure for the fabricated rotors. Feed and plunge feed have been identified as the most influencing variable parameters as per an analysis of variance (ANOVA) test. The lowest average roughness value obtained by this process for the rotor blade was 0.11 µm. A micrograph obtained from a field-emission scanning electron microscope (FE-SEM) showed a uniform and accurate tooth profile along with burr formation at corner edges. This study claims to establish engraving milling as a viable alternative to other manufacturing processes used for rotor blades. The findings of this study are useful to scholars, engineers, and researchers who are exploring new ways to fabricate mechanical parts and components.

Calculation of force parameters of workpiece machining process with end mill cutters

The aim is to develop and validate an operational methodology for calculating the force parameters and characteristics of the tool and the process of milling structural materials with end milling cutters. The structural schemes of machining and force models of oblique cutting processes in the modes of axial tool feed and continuous plastic deformation of the processed material were used when developing the method of preliminary calculation of the total axial force working on the cutting edge of end milling cutters. The rotating tool tests were conducted on a Hermle UWF 1202 H 3-axis machining center supplemented with a Kistler piezoelectric dynamometer (model 9272). Authors suggested, developed and tested the preliminary calculation method applied to the force characteristics of the machining process of workpieces by end milling cutters, considering how the energy power of ductile fracture of the machined material affects the process. Contact friction arising on the front and rear surfaces of the cutting tool does not reach the limiting value being subject to the Coulomb – Amonton law, that is, it is estimated by the dependence directly proportional to the normal pressure. After calculations, we defined the materials of the workpiece for milling, that is 45 steel (AISI 1045), and the end two-tooth cutter, uncoated T14K8 alloy, which was used to produce samples. The following milling modes were established: 4 mm boring depth; 50, 100 and 150 m/min cutting speeds; 0.05 and 0.1 mm/rev cutting tool feed. Deviation of the measured values of axial cutting force from the calculated values in the range of changing values of tool feed rate was found to be no more than 11%, and in the range of changing values of cutting speed no more than 15%. The developed calculation and analytical methodology for estimating force parameters of the machining process by end milling cutters provides an increase in the efficiency and reliability of the preliminary prognostic calculation of operating parameters and characteristics of cutting elements of end milling cutters.

Optimized Material Removal and Tool Wear Rates in Milling API 5ST TS-90 Alloy: AI-Driven Optimization and Modelling with ANN, ANFIS, and RSM

One of the performance measures and responses in manufacturing is the optimization of the Material Removal Rate (MRR) and Tool Wear Rate (TWR). This study used the response surface method (RSM) and AI-based models of artificial neural networks (ANNs) and adaptive neuro-fuzzy inference systems (ANFISs) to model and optimize the MRR and TWR for milling API 5ST TS-90 alloys. A ZX6350C milling machine was used to conduct twenty (20) experimental runs using a 10 mm HSS end-mill cutter. The experiment was designed using Central Composite Design (CCD) in Design Expert 14 software. RSM, ANN, and ANFIS models were applied in the predictive modelling of the milling process with a coefficient of determination above 0.85. Comparatively, ANFIS and RSM were marginally better than ANN in the predicted MRR for the milling process. The ANFIS and RSM were slightly better than ANN in the predicted TWR for the milling operation. Generally, ANFIS showed a better predictive capability than RSM and ANN for both MRR and TWR. The optimum process milling parameters for the alloy were a 720-rpm spindle speed, 24 mm/min feed rate and 0.979 mm depth of cut to achieve an optimized predicted MRR of 1272.163 mm3/min and TWR of 0.781 mm/min. The optimum milling process was validated at the suggested experimental conditions by carrying out the milling experiment at those conditions, and the results of 1270.05 mm3/min for MRR and 0.77 mm/min for TWR showed a close correlation between the predicted and validated optimum. The optimum milling parameters from this study would enhance production at reduced tooling costs associated with tool wear.

Eco-friendly sustainable machining with MoS2-based solid lubricant

Machining is one of the basic and inevitable operations in the manufacturing industry. The machining performance is estimated based on various parameters like cutting forces, surface roughness, tool–chip interface temperature, and specific energy. In the traditional approach, cutting fluids are greatly utilized to dissipate the generated heat during machining, but their utilization causes a threat to nature and human being’s health. Therefore, there emerges a necessity to determine user-friendly, sustainable, and eco-friendly substitutes for traditional cutting fluids. The field of advanced tribology has proposed the usage of solid lubricants due to their inherent properties, such as excellent tribological performance, reduced machining zone temperature due to lowered friction, and enhanced tool life. Therefore, in the present study, pure MoS2 and composite MoS2–TiO2 solid lubricants have been employed in the milling process of AISI 52100 steel with HSS end mill cutter. The machining was carried out in different conditions such as uncoated tool without use of lubricant, uncoated tool with use of lubricant, coated tool without use of lubricant, and coated tool with use of lubricant that were employed to analyze their effect on machining performance. The experimental results showed substantial improvement regarding reduced cutting forces, reduced temperature at tool–chip interface, improved surface finish, and average tool wear with the application of solid lubricants. Among the various lubricating conditions, composite MoS2–TiO2-coated tool with composite MoS2–TiO2 lubricant exhibits excellent machining performance.

Performance evaluation of high-pressure cooling by using external rotary liquid applicator in milling Ti–6Al–4V alloy

An effective cooling mode with appropriate process parameters can enhance the machinability as well as productivity. In this regard, this study focuses on evaluating the machinability of widely used Ti–6Al–4V alloy with the use of high-pressure coolant jets compared to dry milling. A novel rotary applicator was designed and developed to feed high-pressure coolant jets without any drastic change of solid end mill cutter. Four flutes solid HSS end mill cutter was selected for machining because of its some intensive properties. Biodegradable VG-68 cutting oil was chosen as cutting fluid due to its better thermo-physical properties with higher flash points. Machinability was assessed at 16–32 m/min cutting speeds and feed rates of 0.08–0.16 mm/tooth with a constant depth of cut of 1.0 mm, taking into account the average cutting temperature, resultant cutting force, mean surface roughness, and tool wear. Dry milling produced the worst results for all of the investigated responses, with excessive tool wear due to the lack of cooling and lubrication. Compared to dry milling, high-pressure cooling (HPC) lowered average cutting temperature, resultant cutting force, and mean surface roughness by 11.21–21.57%, 8.63–13.12%, and 6.09–29.6%, respectively, whereas rotary high-pressure cooling (RHPC) reduced these parameters by 15.39–27.27%, 14.05–21.18%, 16.48–41.04%. RHPC's efficient cooling and lubrication increased the machinability of the Ti–6Al–4V alloy. Dry milling showed severe flank wear with increased built-up edge (BUE) development, abrasion, and adhesion, whereas HPC and RHPC dramatically reduced the severity of tool wear. In HPC and RHPC, the tool life was consequently increased by 6.8 and 9 min, respectively.

Sharpening of graded diamond grinding wheels

Grinding the flutes of cemented carbide end mill cutters results in high and uneven radial wear of the grinding wheel. This is a consequence of the varying geometrical contact conditions over the grinding wheel width. Decreased manufacturing accuracy regarding the tool target geometry is the consequence. To compensate for this, the dressing intervals must be shortened. High non-productive times and an additionally reduction of the grinding layer results from this. The higher non-productive times reduce the productivity of the grinding process and, in conjunction with the shorter lifetime of the grinding tool, thus increase the costs per work piece. It has already been shown that load-adapted grinding wheels can reduce uneven radial wear up to 50%. The adaptation of the wear behaviour to non-uniform engagement conditions causes non-uniform radial wear to occur again under uniform engagement conditions. Uniform engagement conditions occur during grinding wheel sharpening. Therefore, the present study investigates the influence of sharpening on the grinding tool topography. For this purpose, sharpening tests are carried out on four differently graded grinding wheels. For comparability, the tests are also carried out on two non-graded grinding wheels. In the present work, the surface parameters are evaluated with regard to their suitability for analysing the sharpening condition of graded grinding wheels. The grain protrusion derived from this is subsequently used for evaluation. For this, a dependency on the grain concentration is proven and the grain protrusions are shown over the grinding wheel widths. From this, sharpening parameters are determined that enable reproducible sharpening of graded grinding wheels.

High-Speed Machining of Ti–6Al–4V: RSM-GA based Optimization of Surface Roughness and MRR

This article offers experimental research into getting the lowest possible roughness on the surface profile of Ti–6Al–4V produced by High-Speed Machining (HSM) in conjunction with the highest feasible material removal rate (MRR). All three machining variables—cutting speed (mm/min), feed rate (mm/min), and depth of cut (μm)—are investigated in this experiment. The combined optimization of Response Surface Methodology (RSM) and Genetic Algorithm (GA) are used to optimize the cutting parameters for a high-speed end milling operation. For the 20 distinct runs that CCD (Central Composite Designs) offers, employing uncoated cemented carbide end mill cutters is a more affordable choice for cutting the alloy Ti–6Al–4V. Machining data are analyzed with Design Expert software and MATLAB, respectively, utilizing RSM and GA. It has been shown that speeding up the cutting speed (105.56–138.86 mm/min) while decreasing the feed rates (25–37 mm/min) improves surface roughness. The minimum achievable surface roughness predicted by GA and RSM are 0.063 μm and 0.093 μm, respectively. This study presents that the desirability of getting the optimum result would reduce sharply (26.39%) by sacrificing the surface roughness for only 0.1 μm. The cutting edge will be ready for machining with optimum machining combination (cutting speeds of 105.56 and 138.86 m/min and feed rates of 25 and 37 mm/min). The findings illustrate that lowering the surface roughness by only 0.1 μm will increase the MRR rapidly (50.83%). A comparative study on the MRR is also conducted within the investigated input parameters range. The morphology of tool wear and the texture of the machined surface are examined using scanning electron microscopy (SEM) pictures.

Examination of surface roughness values of 6061-T6 aluminum material after machining and after anodizing process

The use of aluminum material is very common, especially in parts that require precision mechanical processing, such as in the aerospace or defense industry. Since weight reduction in related vehicles or technologies in the fields of aviation and defense industry is one of the biggest goals, the use of aluminum as a metal material has become one of the first targets. The high weight/strength ratio of aluminum compared to steel is one of the main reasons why it is preferred. In addition to these advantages of aluminum materials, we have two expectations for 6061 aluminum parts in most of the projects we work on. The first is to minimize the frictional intensity of the aluminum parts working in contact with each other. The second is to provide the surface roughness of the gasket pressing surface on the surfaces where gaskets are used due to the need for sealing. For both requirements, our goal in this study will be to achieve the surface roughness value as maximum Ra 0.2 after machining and maximum Ra 0.3 after anodizing. The study was carried out with six different cutting tools. These tools, in order; end mill (with one insert) cutter, end mill (with two inserts) cutter, solid end mill, single insert diamond tool, monocrystalline diamond tool and superfinishing tool. Particular attention was paid to the cleanliness of the chemical baths used in the anodizing specific to this study. As a result, it has been observed that much more precise results can be achieved than the currently accepted surface roughness value when suitable machining parameters and optimum anodizing coating parameters are used. By using different cutting parameters with the same tool, by increasing the speed and feed values and decreasing the depth of cut, there is a slight improvement in the surface roughness values. The results of the experiments are presented in table and graphic and are suitable only for observed cutting conditions, used tools and material.

Study of the Machinability of an Inconel 625 Composite with Added NiTi-TiB2 Fabricated by Direct Laser Deposition

This work studies the process feasibility of milling a metal-matrix composite based on Inconel 625 with added NiTi-TiB2 fabricated by direct laser deposition. The composite is intended for manufacturing turbine blades and it has strength characteristics on par with those of Inconel 625. However, the addition of TiB2 has improved its heat and wear resistance. This material is new, and its machinability has not been studied. The new composite was milled with end mill cutters, and recommendations were worked out on the cutting speed, feed per tooth, cutter flank angle, as well as depth and width of milling. The wear of cutter teeth flank was more intense. After the flank wear land on the back surface of a tooth had reached 0.11–0.15 mm, there was a sharp increase in the forces applied which was followed by brittle fracture of the tooth. Milling at a speed of 25 m/min ensured 28 min of stable operation. However, afterwards the critical wear value of 0.11 mm was quickly approached at a cutting speed of 50 m/min, and critical wear followed after 14 min. Dependencies of the cutting forces vs. time for all the selected cutting speeds and throughout the entire testing time period have a tendency to increase, which indicates the influence of cutter wear on the cutting forces. It was found that the durability of the cutters increases with an increase in the milling width and a decrease in the milling depth.

Tool Condition Monitoring Using Machine Tool Spindle Electric Current and Multiscale Analysis while Milling Steel Alloy

In the metal cutting process, the tool condition directly affects the quality of the machined component. To control the quality of the cutting tool and avoid equipment downtime, it is essential to monitor its condition during the machining process. The primary purpose is to send a warning before tool wear reaches a certain level, which could influence product quality. In this paper, tool condition is monitored using fractal analysis of the spindle electric current signal. The current study analyzes the monitoring of the cutting tool when milling AISI 5140 steel with a four-flute solid carbide end mill cutter to develop monitoring techniques for wear classification of metal cutting processes. The spindle electric current signal is acquired using the machine tool internal sensor, which meets industrial constraints in their operating conditions. As a new approach, the fractal theory is referred to analyze the spindle electric current signal and then assess the tool wear condition during the metal cutting process. Fractal parameters were defined to extract significant characteristic features of the signal. This research provides a proof of concept for the use of fractal analysis as a decision-making strategy in monitoring tool condition.

Effect of end milling parameters on MRR and hardness variation of AA7075

The end milling process is a bulk machining process used for machining an edge surface on the part, making slots, pockets, dies and moulds. Aluminium alloy 7075 (AA7075) is an alloy, with zinc as the principal alloying element. It shows good ductility, high strength, toughness, and fatigue resistance. It is one of the most used aluminium alloys for highly stressed structural applications and is widely applied in aircraft structural parts.By considering the application of AA7075 and uses of the milling process in product manufacturing, the present work focuses on studying the effect of End milling process parameters in the milling of AA7075 plate by varying three distinct parameters: Cutting speed (S), Feed (f) and Depth of cut (d). The output parameters measured were Material Removal Rate (MRR) and Hardness (BHN) variation on the machined surfaces. The BHN of the machined surfaces varied from 178 to 260 BHN. Similarly, the MRR varied from 1500 to 13200 mm3/sec. The down milling experiments were conducted as per Taguchi’s L9 orthogonal array on a 6 mm thick plate using a solid carbide end mill cutter of 10 mm diameter.The effect of milling process parameters on selected responses was analyzed, and the optimization of process factors for maximization of MRR and hardness was carried out to improve the machinability of AA7075 alloy.

Metallurgical and machining performance aspects of cryotreated tungsten carbide micro-end mill cutters

Demand for miniaturized parts with tight geometrical tolerances and superior surface finish has been increasing. Development of micromachining processes has enabled adaptation of miniaturized parts and products in mechanical systems. Machining at the microscale level has supplementary challenges like high cutting forces, reduced tool life, and damaged machined surfaces. Catastrophic failure of microtools is notable problem, if tool deflection increases significantly. Therefore, incorporating tool life improvement measures are essential to minimize tool replacement cost and also to achieve efficient cutting at micro-level. Cryotreatment imparts better physical properties to cutting tools. In the present work, effects of different cryogenic treatment parameters on micro tungsten carbide-cobalt (WC-Co) end mill cutters and its performance while machining Ti-6Al-4V have been investigated. The metallurgical changes imparted to cutting tool by cryotreatment are studied via micro-hardness test along with EDS, SEM and XRD methods. It is found that all cryotreated tools have higher hardness compared to untreated tools. Additional η (eta) carbide formation has been clearly observed for the tools soaked for 24 h, moreover a variation in other phase of WC is also observed for different set of cryotreatment. Machining process is significantly affected by the low thermal conductivity of Ti-6Al-4V. In case of untreated micro-milling tool, abrasive wear is dominant, whereas built-up-edge affected the performance of cryotreated tools at shallow cryotreatment temperatures for 8–16 h soaking time. Deep cryotreated tool (at 24 h soaking time) performed better in terms of cutting force and surface roughness due to retainment of sharp cutting edge.

Measurement and optimization of multi-attribute characteristics in milling epoxy granite composites using rsm and combined ahp-topsis

Epoxy granite composites with its wide range of applications in machine tool industries are manufactured by molding process and require post cast machining operations to meet the desired dimensional accuracy for assembly of machine tool structures. In this research work, milling of epoxy granite composites are carried out based on the experimental design from Response Surface Methodology (RSM) techniques and further the optimal solutions are determined by a novel hybrid algorithm AHP-TOPSIS. Central Composite Design (CCD) model is applied with three factors-three levels and the measured output responses are thrust force, tangential force and surface roughness. Experimental combinations of 20 different trials are performed using high speed steel end mill cutter of diameter 10 mm with three levels of input parameters: speed; fibre content and feed rate at a uniform depth of cut. The relative importance matrix formulated proved to be highly consistent with its consistency ratio to a maximum of 0.000641 which lies below the higher range of 0.1. Consistency ratio of 0.000641 reveals that the optimal solutions determined will be highly reliable and the decision making is much more judicious. Optimal solution determined from hybrid AHP-TOPSIS methods are: speed 1800 rpm; feed rate 0.03 m min−1 and 0% percent fibre content. Functional relationships among parameters and responses established by RSM are consistent upto 95% and its significance is tested by analysis of variance. Comparison among predicted and experimental values of three measured responses convey that the percentage variations are minimum with up to 2.03% for surface roughness, 2.50% for thrust force and 2.71% for tangential force components. This research work provides a systematic procedure and clear framework for determination of optimal machining conditions by hybrid methodology on the basis of technique for order preference by similarity to ideal solution (TOPSIS) combined with analytical hierarchy procedure (AHP) for attribute weights and further analyzes the influence of machining parameters over measured responses.

Operational behaviour of graded diamond grinding wheels for end mill cutter machining

The varying related material removal rate during deep grinding of cemented carbide end mill cutters results in an unevenly wear of the grinding wheel. This study therefore presents a simulation-based model for the load-adjusted design of grinding wheels to achieve balanced radial wear, as well as an evaluation of this model. The related material removal rate along the width of the grinding wheel is determined by a Dexel based material removal simulation for different end mill geometries. Based on these results an equation is derived to adapt the abrasive layer properties to the local load differences. Three grinding wheels with different types of gradients are then manufactured by a grinding tool manufacturer based on this equation. These and two grinding wheels with constant abrasive layer properties are used for deep grinding of ten end mills each. Afterwards the radial wear of each grinding wheel is measured by a confocal microscope. An analysis of the cutting edge chipping is done to evaluate the influence on the graded grinding wheels on the cutting edge quality. It was found that a reduction of the wear difference over the grinding wheel width of 52% and an improved cutting edge quality can be achieved by using graded grinding tools. This allows the time intervals between dressing steps to be increased without compromising the accuracy of the grinding process, thus also increasing its productivity. Finally, this article shows that the presented model allows for a more balanced wear behaviour, but has to be extended by considering further factors influencing radial wear.

Digital generating method for cylindrical helical gear based on indexable disk milling cutter

To solve the problem of low efficiency in digital generating machining for producing small or medium batches of helical gears, a method to improve the machining efficiency with an indexable disk milling cutter is presented in this paper. First, the mathematical model of the tooth profile and the indexable disk milling cutter are established. Second, according to the spatial free-form envelope theory, the overall planning scheme of the tool path is given; the relative position and the relative transformation matrix of the tool and tooth profile during digital generating machining using the indexable disk milling cutter are solved, the simulation cutting and actual cutting experiments are conducted, and the cutting efficiency per unit time and cutting simulation time of the two tools under the same deformation conditions is obtained through a finite element analysis experiment. The results show that the cutting efficiency of the indexable disk milling tool was 2–3 times higher than that of the end mill cutter.