Vertical Milling Center Research Articles

Tribological analysis of cooling tank assisted hybrid friction stir welded 6061 aluminum alloy

: In the present work, the friction stir welding of aluminum alloy was done on the hybrid storage tank-assisted fixture at the Vertical Milling Centre. The three different storage media were used as air, water, and coolant. This study aimed to examine the effect of the cooling media in the hybrid fixture on the wear, coefficient of friction, hardness, and worn surface. The tool of mild steel was used for the welding process, and the wear of the tool was also examined for a better recommendation of tool material. In the FSW of the coolant-type welding process, it was found that the least wear was obtained at the different welding conditions. The higher rotational speed welded FSW joint increases the wear. The coefficient of friction exceeds the base material at 900 rpm in the FSW-W type joint. The average value of friction force at 500 rpm and 1000m sliding distance was 3N FSW air (FSW-A) and 5N base material. The average value of FF at 700 rpm and 1000m sliding distance was 1N FSW-A and 6 N for base material. The FF at 900 rpm was 5N FSW water type (FSW-W) and 1 N for FSW -A.

Microstructural analysis of cooling tank-assisted hybrid friction stir welded aluminium alloys: a novel approach

The friction stir welding process is a solid-state technique for joining similar and dissimilar alloys. The advanced fixture was designed and fabricated for welding of the aluminum plate by a hybrid fabricated fixture on a vertical milling center. The storage tank was designed and attached at the bottom of the base plate of the fixture. The three different cooling media used in the cooling tank as air, water, and coolant. The welded samples were examined for mechanical and metallurgical performance. The optimization of process parameters was done for the tensile Test as output. The coolant as a fluid in the tank results in maximum tensile strength at 500 rpm. The microstructural characterization of the heat-affected zone was also done. The weld thinning and quenching are the main problems of direct cooled FSW. This problem is not found in the indirect cooled FSW welding method. The storage tank provided uniform heating and cooling during welding that reduced the thermal quench and microstructural problems. The SEM and EDX mapping images showed the effect of different cooling media on the FSW samples. The microhardness was analyzed to identify different microstructural zone and the hardness of welded part.

Optimisation and modelling of burr formation during face milling of rolled steel (AISI 1040) using Taguchi approach

ABSTRACT Burr formation on the edge of the machined part during face milling is a common phenomenon. Highly precise and accurate parts are required to be burr free. Generally, deburring (secondary operation) is performed to remove the burr, which leads to the cost of the part. The aim of this study is to obtain minimum exit burr by optimising the input parameters at primary stage of the face milling operation. Effect of machining parameters (cutting velocity, feed per tooth, axial depth of cut), and machining strategies (rolling direction, cutter offset, soaking time during heat treatment) are taken into consideration. Taguchi’s L27 matrix is selected for the design of experiments. Face milling of rolled steel (AISI 1040) is performed on vertical milling centre using titanium nitride coated carbide inserts. Exit burr is evaluated as a signal to noise ratio. The significance level and percentage contribution of parameters are calculated using analysis of variance. Cutter offset has shown maximum contribution followed by cutting velocity. Burr reduction of 58.4% is observed during a confirmation test. Finally, multi-variable linear regression is employed to generate second-order empirical model. Adequacy of model is checked by residual analysis.

Experimental Studies on Die based Two Point Incremental Forming

Incremental sheet forming (ISF) is an interesting new field of study in rapid sheet metal forming. ISF employs a basic mould to make parts with curved surfaces that do not require special equipment. To fulfil the needs of small scale and diversified markets around the world and address the difficulties of long production cycles and high prices, this technique has a wide variety of uses from aerospace to medical research. This work attempts to develop a Two Point Incremental Forming (TPIF) setup for the forming of stainless steel (AISI 316 L) sheets of uniform thickness. In this work, the forming process has been carried out by varying process parameters such as tool diameter, step depth, spindle speed and feed rate. Forming is carried out in a Vertical Milling Centre (VMC) with a hemispherical tungsten carbide tool. The output responses such as wall angle of the formed component, forming time, surface roughness, depth of the formed component was measured and was compared with the selected input parameters.

Research, Modelling and Prediction of the Influence of Technological Parameters on the Selected 3D Roughness Parameters, as Well as Temperature, Shape and Geometry of Chips in Milling AZ91D Alloy.

The main purpose of the study was to define the machining conditions that ensure the best quality of the machined surface, low chip temperature in the cutting zone and favourable geometric features of chips when using monolithic two-teeth cutters made of HSS Co steel by PRECITOOL. As the subject of the research, samples with a predetermined geometry, made of AZ91D alloy, were selected. The rough milling process was performed on a DMU 65 MonoBlock vertical milling centre. The machinability of AZ91D magnesium alloy was analysed by determining machinability indices such as: 3D roughness parameters, chip temperature, chip shape and geometry. An increase in the feed per tooth fz and depth of cut ap parameters in most cases resulted in an increase in the values of the 3D surface roughness parameters. Increasing the analysed machining parameters did not significantly increase the instantaneous chip temperature. Chip ignition was not observed for the current cutting conditions. The conducted research proved that for the adopted conditions of machining, the chip temperature did not exceed the auto-ignition temperature. Modelling of cause-and-effect relationships between the variable technological parameters of machining fz and ap and the temperature in the cutting zone T, the spatial geometric structure of the 3D surface “Sa” and kurtosis “Sku” was performed with the use of artificial neural network modelling. During the simulation, MLP and RBF networks, various functions of neuron activation and various learning algorithms were used. The analysis of the obtained modelling results and the selection of the most appropriate network were performed on the basis of the quality of the learning and validation, as well as learning and validation error indices. It was shown that in the case of the analysed 3D roughness parameters (Sa and Sku), a better result was obtained for the MLP network, and in the case of maximum temperature, for the RBF network.

"Status of Farm Machinery Manufacturing in Madhya Pradesh: A Case study"

"The objective of this paper was to assess the current status of farm machinery manufacturers in Madhya Pradesh along with farm machinery market size, production potential and demand of farm machinery using primary data. To achieve the goal, primary data were collected through pre-tested and wellstructured proforma in 2017-18 adopting post-stratified random sampling technique. The market size of farm machinery manufacturing sector was estimated to be INR 7.56 (±0.21) Billion. There were 53% manufacturers with an annual turnover less than INR 10 Million and only 3 % manufactures had annual turnover more than INR 150 Million. High coefficient of variation for advance tools like vertical milling centre (660%) and CNC (Computer numeric control) machine (358%) indicated non uniform utilization of advance tools which affects the quality of manufactured farm implements. The survey conducted in the study region had manufactures producing around 45 different farm implements for agriculture. Investigation revealed that the production of the implements like rotavator, laser land leveler, reaper, combine harvester, chaff cutter and spray were less than its demand, which prompted the users to import these implements from neighboring States like Gujarat, Rajasthan and Punjab. The study showed that 43 % of the total manufacturers were integrated with Madhya Pradesh Government subsidy scheme. The manufactures of Madhya Pradesh also exported farm implements like reversible Mould Board plough to South Asian country and other developing country"

Influence of constructive and geometric parameters of the end cutters on the microprofile characteristics of casting surfaces

The object of research is the technological route of machining of an aluminum alloy casting. The research carried out is based on the basic principles of functionally oriented design of technological processes in the manufacture of products. The main hypothesis of the study is the need for a systematic approach to study the effect of cutting modes of a certain method of machining on the provision of quality parameters in the technological system (machine – device – tool – workpiece). In traditional automated systems for technological preparation of production, an object-oriented principle of designing technological processes is implemented, which provides for the step-by-step implementation of interrelated stages based on a prototyping algorithm without a functional analysis of the operational characteristics of the product. The processing of functional, mating surfaces, ensuring that the product performs its service purpose, must be implemented according to the principle of function-oriented design (FODT). A characteristic feature of FOT is the technological provision of effective operational characteristics of the product in compliance with the parameters of accuracy and quality of the surface layer of the product intended by the designer. The paper deals with the influence of the structural and geometric parameters of end mills manufactured by Sandvick (Sandviken, Sweden) on the formation of microrelief parameters of an aluminum alloy casting profile during machining on a numerically controlled vertical milling center (CNC) HAAS MINIMILL (USA). An atypical option for the FOT principle of the technological route of machining the surfaces of workpieces of machine-building products has been applied. Its feature is ignoring the requirements of the manufacturer of metal-cutting tools, which is an important element of the technological system (machine – tool – device – workpiece), regarding its use for a particular machine tool at a certain technological transition of machining. The performance criteria were the height and step characteristics of the microrelief of the profile of the surface layer of the workpiece being processed. The operating conditions of machine-building products have been determined, which make it possible to establish, in case of deviation from the manufacturer's recommendations at the stage of technological preparation of production, the rational elements of a certain technological system: a metal-cutting machine – a device – a metal-cutting tool – a workpiece and processing modes to ensure the necessary operational characteristics.

Tapping Tool Cost Analysis in CNC Vertical Milling Centre

Tapping Tool Cost Analysis in CNC Vertical Milling Centre

Optimisation of a Spindle Body Considering the Vibration Prediction of the Entire Milling Centre Construction

Static and dynamic properties of machine tools have a decisive influence on their accuracy. In case of HSM machine tools, the phenomena associated with them are additionally strengthened by high machining parameters. In order to predict a machine tool behaviour at the design stage, it is necessary to use numerical methods to simulate for its simulation. Thanks to the use of this type of software, it is possible to perform the next step, i.e. the optimisation of the structure. In case of machine tools, due to the multiplicity of factors affecting its accuracy, this should be a multicriterial optimisation. This article presents the results of a vertical milling centre spindle body optimisation using the Finite Element Method. The results of static stiffness and vibration frequency analysis for three bodies (i.e. the body of the form and dimensions proposed by the constructor, the body after parametric optimisation and the body after the form and parametric optimisation including use of different materials) were compared. The optimisation tools available in the ANSYS system were used for the simulation. The calculations were preceded by experimental research and modifications of dynamic parameters performed on their basis using the author's methodology to determine the behaviour of a partially existing structure for different masses of the body being optimised.

Residual learning of the dynamics model for feeding system modelling based on dynamic nonlinear correlate factor analysis

Feeding system modelling is the foundation for control strategy optimization, contour error compensation, etc., to improve the productivity and quality of a part. This paper proposes a novel residual learning approach for fitting the simulation error of the dynamics model of a machine tool feeding system. Then, the feeding system model consisting of the dynamics model and the residual model is constructed by integrating prior knowledge with statistical learning knowledge. The residual model is trained by using the training dataset generated from the dynamics model instead of using only the input and output data (i.e., the end-to-end data). In addition, a dynamic nonlinear correlate factor extraction method is proposed to extract the training dataset from the dynamics model and the reference data. Compared to the end-to-end data, the training dataset knows very well about the system’s nonlinear features owing to the internal prior knowledge of the dynamics model. Experiments conducted on a vertical milling centre confirm the effectiveness of the feeding system model in dynamic response prediction. Compared to the existing dynamics or data-driven modelling method, the proposed method can achieve higher prediction accuracy in nonlinear motion processes, such as the reverse process, and can obtain stable performance with respect to different feedrates owing to the residual learning approach.

Convolutional neural network-based tool condition monitoring in vertical milling operations using acoustic signals

Sonic monitoring presents itself as one of the least invasive but easiest to implement methods of machine condition characterization. This work investigates the viability of categorically classifying cutting tool wear using only sonic output from a vertical milling center and proposes a statistical model of milling acoustic signals as well as a novel machine learning-integrated method of acoustic signal differentiation. To this end, a deep convolutional neural network is used for data classification. Experimental results support the proposed sonic model and demonstrate that tool wear classification accuracy as high as 99.5% is possible using a two-dimensional deep convolutional neural network.

Measurement of delamination and tool wear with sensors in end-milling using solid and carbide-tipped K10 end mills

An investigation on the machinability of glass-fibre reinforced plastic (GFRP) fabricated using hand moulding was conducted on a vertical-milling centre (VMC) with solid K10 carbide and carbide-tipped K10 end mills having four flutes. This revealed that the machinability of GFRP depends on tool wear and delamination. Sensor-fusion techniques were used to measure tool wear and delamination and the tests were conducted utilising a Taguchi L8 orthogonal array that included the data from the sensors' output. These tests illustrated the suitability of the sensor technique for online monitoring of delamination and tool wear and for improving the machinability of composites for a wide variety of applications. The results showed that using solid carbide end mills leads to less delamination of materials during milling of GFRP and carbide-tipped end mills resulted in little tool wear or change in the depth of cut when used at high speeds along with an appropriate feed rate.

Wpływ wybranych warunków skrawania na siłę i moment podczas wiercenia żeliwa szarego

The impact of selected cutting parameters (cutting speed and cutting feed) on the torque and cutting force during drilling gray cast iron EN-GJL-250 was analyzed. The drilling operation was carried out by Allied Machnie drill series: DEM22000S-20FM, on the Hermle B300 vertical milling center. The measurement of the torque and the cutting forces during drilling was carried out by Kistler device.

Tapping Tool Life Assessment in Vertical Milling Centre in the CNC Production Centre

Tapping process in Computer Numerical Centre, is a key for the process because of its difficult to hold the close tolerance. During this study different types of tapping tool manufacturer have taken with same tapping tool material specification for the consideration. And also to find the relationship between the previous operational performances with tool and its parameter influence in the computer numerical control system has also taken for the consideration. During drilling process the new drill bit (drill bit 4) have higher tool life than the regained tool bits (Drill bit 1, 2 & 3). During tapping process, Emuge tool 2 and Emuge tool 3 have has higher production rate such as 434 and 356 components respectively. This Emuge tool 2 and tool 3 have previous working tool in the drilling process is drill bit 4 (New Drill Bit). Which has improved the surface roughness than the other drill bit. Due to reduced surface roughness causes the taping tool to ease in there processing which resulted in the higher production rate in tapping tool than the other conditions.

EVALUATION OF SELECTED PROPERTIES OF A SURFACE LAYER AFTER MILLING USING INSERTS WITH DIFFERENT COATINGS

The article presents a comparison of results of measurements of the geometrical structure of milled surfaces with inserts with different coatings. The study was done on a vertical milling centre. The first step was to determine the properties of milled surfaces using new inserts. For this purpose, an optical apparatus was used. The samples were then subjected to continuous treatment. Upon completion of the declared quantities of machining cycles, these surfaces were analysed. This allowed us to determine the influence of the coating of the inserts on the surface layer of milled surfaces continuously.

Application of dragonfly algorithm for optimal performance analysis of process parameters in turn-mill operations- A case study

Meta-heuristic multi-response optimization methods are widely in use to solve multi-objective problems to obtain Pareto optimal solutions during optimization. This work focuses on optimal multi-response evaluation of process parameters in generating responses like surface roughness (Ra), surface hardness (H) and tool vibration displacement amplitude (Vib) while performing operations like tangential and orthogonal turn-mill processes on A-axis Computer Numerical Control vertical milling center. Process parameters like tool speed, feed rate and depth of cut are considered as process parameters machined over brass material under dry condition with high speed steel end milling cutters using Taguchi design of experiments (DOE). Meta-heuristic like Dragonfly algorithm is used to optimize the multi-objectives like ‘Ra’, ‘H’ and ‘Vib’ to identify the optimal multi-response process parameters combination. Later, the results thus obtained from multi-objective dragonfly algorithm (MODA) are compared with another multi-response optimization technique Viz. Grey relational analysis (GRA).

Model‐Based Dynamic Structural Modification of Machine Tools

The article proposes modification of machine tool structures methodology on the example of a body of vertical milling centre stand. It is based on the results of experimental research and allows for the prediction of dynamic features of individual bodies and complete structures on the basis of the described modal model. It takes into account the possibility of mass change at the model node and the introduction of additional rigidity and damping by a combination of selected nodes of the model. The methodology can be applied in the case of machine tools in which the loss of stability has been found during its maintenance, what consequently disables the possibility of machining with the required machining parameters from the performance point of view. Modal parameters modification is based on structural dynamic modification techniques and preliminary simulation tests performed by using Finite Element Method (FEM) and verification with experimental research.

A cuckoo search optimisation-based Grey prediction model for thermal error compensation on CNC machine tools

PurposeThe purpose of this paper is to produce an intelligent technique for modelling machine tool errors caused by the thermal distortion of Computer Numerical Control (CNC) machine tools. A new metaheuristic method, the cuckoo search (CS) algorithm, based on the life of a bird family is proposed to optimize the GMC(1, N) coefficients. It is then used to predict thermal error on a small vertical milling centre based on selected sensors.Design/methodology/approachA Grey model with convolution integral GMC(1, N) is used to design a thermal prediction model. To enhance the accuracy of the proposed model, the generation coefficients of GMC(1, N) are optimized using a new metaheuristic method, called the CS algorithm.FindingsThe results demonstrate good agreement between the experimental and predicted thermal error. It can therefore be concluded that it is possible to optimize a Grey model using the CS algorithm, which can be used to predict the thermal error of a CNC machine tool.Originality/valueAn attempt has been made for the first time to apply CS algorithm for calibrating the GMC(1, N) model. The proposed CS-based Grey model has been validated and compared with particle swarm optimization (PSO) based Grey model. Simulations and comparison show that the CS algorithm outperforms PSO and can act as an alternative optmization algorithm for Grey models that can be used for thermal error compensation.

Finishing Surface After Regeneration with Laser Cladding

This article has presented the results of experimental research concerning the regeneration process of flat sheet metal made of C45 steel, which is difficult to weld. The regeneration process included filling the material defect of 20×20×0.75mm with laser cladding with a powder form additive. Rough machining of the surface with cladding has been conducted at a vertical milling center, while the finishing work was performed with a surface grinder. The analysis of obtained results has been performed on the basis of measurements of selected parameters concerning the geometrical structure of the regenerated surface treated with machining.

Ocena dokładności wykonania czopa okrągłego z wykorzystaniem różnych strategii obróbkowych na pionowym centrum frezarskim

Ocena dokładności wykonania czopa okrągłego z wykorzystaniem różnych strategii obróbkowych na pionowym centrum frezarskim