Traditional Machining Processes Research Articles

Design, motion-planning, and manufacturing of custom-shaped tools for five-axis super abrasive machining of a turbomachinery blade type component

AbstractFree-form surfaces generated by non-uniform rational B-splines (NURBS) are evolving to face turbomachinery component requirements, such as turbine blades to enhanced efficiency. Super abrasive machining (SAM) is presented as a potential process for high-added value components using custom-shaped tools to be adapted to any surface. The adaptability and flexibility of these tool concepts are specifically designed to fit these complex surfaces. This paper presents an innovative manufacturing approach for blade type components using a custom-shaped tool designed through an optimization process that simultaneously optimizes both the shape of the tool and its motion. The proposed method with SAM finishing using a custom-shaped tool is compared against a standard tool and traditional machining process. The result obtained on the blade test case shows that the custom-shaped tools need fewer paths, yet produce more accurate surface finish.

A Digital Twin Platform Integrating Process Parameter Simulation Solution for Intelligent Manufacturing

The present work aims to develop a digital twin system typical of intelligent manufacturing applications, which has integrated visualization technologies, as well as the process parameter simulation solution. The application under consideration is a typical machining process, with a gantry machine tool controlled by Siemens Programmable Logic Controller(PLC) S7-1200. With the establishment of dual-directional data communication between the physical machine tool and its virtual counterpart based on TCP/IP protocol, real-time visualization, monitoring, and control of the entire working process can be achieved. Furthermore, we integrated with the digital twin system as a solution for real-time process parameter simulation based on finite element modeling (FEM), which enables the real-time monitoring of necessary process parameters, e.g., surface deformation, during the machining process. A preliminary experiment was conducted to validate our proposed digital twin system, and the results demonstrated that our proposed method has satisfactory performance in terms of both control and monitoring of the traditional machining process, and synchronization between the physical and virtual models is also proven to be positive with minimal latency.

Design and Machining of a Spherical Shell Rotor for a Magnetically Levitated Momentum Ball

Ball-shell rotors with non-standard shapes, non-uniform conductive coatings, and eccentric masses machined by conventional processes constrain the improvement of levitation and torque accuracy of magnetically levitated momentum balls. This paper focuses on the machining method of multilayer ball-shell rotors to develop a ball-shell rotor with a standard shape and uniform conductive coating, which can improve the levitation and torque accuracy of magnetically levitated momentum balls. In this paper, a machining method for multi-coated ball-shell rotors is proposed. The machining process combining hemispherical surface and workpiece is adopted, and the whole sphere is assembled by threading, which effectively reduces the machining error. The influence of the cutting depth and feed rate of the tool on the cutting force of the ball shell was analyzed through the cutting force model. The effect of cutting force on the deformation of the ball shell was analyzed by the finite element method. The superiority of the machining method was verified by measuring the dimensions of the ball shell with a coordinate measuring machine. Compared with the traditional machining process and assembly method, the proposed ball-shell rotor machining method effectively improves the dimensional accuracy, reduces the center of mass to center of mass deviation, and ensures the levitation accuracy and output torque accuracy of the magnetically levitated momentum ball. Measurement results show that the diameter values of the pure iron ball shell are between 98.694 and 98.707 mm with a machining error of ±0.007 mm, and the diameter values of the spray-painted ball shell are between 99.490 and 99.510 mm with a machining error of ±0.01 mm. The machining static equilibrium of the pure iron ball shell and the spray-painted ball shell is good by the static equilibrium test method.

Mathematical Model of Material Removal Rate during Milling of AISI D2 Tool Steel Using Response Surface Methodology

The CNC milling process is one of the most valuable traditional machining processes for machining hardened material by using various coated end mill tools. The attention of the current study has been done on end milling of hardened AISI D2 tool steel which is a commonly used tool steel grade in a press machine. The material removal rate is an essential aspect of improving productivity and reducing lead time and production costs. MRR has been considered as a response in this experimental work. A number of experiments were conducted using the design of the experiment via response surface methodology (RSM). MRR was calculated for each machining performance. A mathematical model of MRR was found using response surface methodology.

Effect of Wire Electric Discharge Machining Parameters on Material Removal Rate in Machining of Titanium Grade 7 Alloy

Titanium alloys are widely used in various fields, including the medical field, the automotive and manufacturing sectors. Traditional machining processes are only useful for a limited number of tasks due to the detrimental effects they have on the strength and stiffness of the machined alloys. However, one of the most favoured post-processing equipment used to obtain a high-quality surface is the wire electrical discharge machining (WEDM) technology. The most crucial aspects of WEDM are the rates of the electrical current and voltage, in addition to the pulse-on and pulse-off durations. As a form of wire, WEDM makes use of brass wire that has been zinc-coated. The WEDM method is utilised in the machining of titanium alloy of grade 7 for this project. The surface of titanium grade 7 that had been processed using WEDM was analysed with a scanning electron microscope. The pictures revealed that the material exhibits homogenous solidification and a columnar grain structure along the build direction. As the pulse-on time gets longer, the Material Removal Rate (MRR) also gets higher. When the pulse-on time is set to 60 µs, the greatest MRR that can be achieved is 7.357 mm3/min. As the pulse-off duration gets longer, the MRR is getting lower. At a pulse-off time of 20 µs, the minimal MRR is reached, and it is equivalent to 5.935 mm3/min. At a peak current 6A, the highest MRR is measured is equivalent to 7.795 mm3/min.

Numerical Modeling of a Sustainable Solid-State Recycling of Aluminum Scraps by Means of Friction Stir Extrusion Process.

One of the most important purposes of the modern industry is a sustainable production, considering the minimization of the energy and of the raw materials used, together with the reduction of polluting emissions. In this context, Friction Stir Extrusion stands out, since it allows to obtain extrusions starting from metal scraps deriving from traditional mechanical machining processes (e.g., chips deriving from cutting operations), heated only by the friction generated between the scraps and the tool, so avoiding the material melting phase. Given the complexity of this new kind of process, the objective of this research is the study of the bonding conditions considering both the heat and the stresses generated during the process under different working parameters, namely tool rotational and descent speeds. As a result, the combined approach involving the Finite Element Analysis and the Piwnik and Plata criterion proves to be a valid tool for forecasting if bonding phenomenon occurs and how it is influenced by the process parameters. The results have also demonstrated that it is possible to achieve completely massive pieces between 500 rpm and 1200 rpm, but at different tool descent speeds. Specifically, up to 1.2 mm/s for 500 rpm and just over 2 mm/s for 1200 rpm.

Plastic Shavings by Laser: Peeling Porous Graphene Springs for Multifunctional All-Carbon Applications.

Manufacturing strategies to create three-dimensional (3D) structures with multifunctional nanomaterials are of intense interest for fabricating building blocks in many electromechanical applications. A coil spring composed of graphene provides an important step toward the realization of all-carbon devices, as it is one of the essential elements for a wide range of systems. In this connection, here an unprecedented fabrication strategy to create a new type of 3D coil spring composed of laser-induced graphene springs (LIG-S) which is spontaneously produced via the pyrolytic jetting technique, is presented. Similar to wood or metal shavings observed in traditional machining processes, a pair of LIG-S with two opposite chiralities and controllable macroscopic dimensions is produced by a single scanning of a focused continuous-wave (CW) laser on a polyimide (PI) substrate. The resulting LIG-S, plastic shavings by laser, exhibits sufficient mechanical and electrical properties to enable many applications including strain-tolerant spring electrodes, antennas, supercapacitors, gas sensors, and luminescent filaments under extreme conditions. Without using any conventional fabrication techniques or other labor-intensive, time-consuming, and expensive processes, this novel approach enables a high-throughput mass production of macro-, micro-, and nanoscale featured LIG-S that can be manufactured within seconds to realize many open opportunities in all-carbon electromechanical systems.

Investigation on Surface Roughness and MRR in WEDM of Titanium Grade 7 (Ti-0.15Pd) Alloy using Statistical Techniques

Wire Electric Discharge Machining (WEDM) of Titanium grade alloys with coated electrodes has several advantages over the traditional machining process such as increased productivity, reduction of processing cost, and improved material properties. The main objective is to create a relationship between WEDM parameters such as Pulse-on (TON), Pulse-off (TOFF), and Indicated Power (IP) with surface roughness (Ra) and Material Removal Rate (MRR). In the present work, the performance of zinc-coated brass electrodes for WEDM of Titanium Grade-7 alloy was assessed and optimized with statistical technique. ANOVA analysis is used to analysis of the MRR and Ra and validated with regression. The ANOVA analysis results indicated that TON is the highest statistically significant and followed by TOFF and IP on MRR and surface roughness. The optimum combination of higher IP(6 A) and TON time(60 μs) and lower TOFF time (12 μs) is lucrative for a higher MRR of 8.5682 mm3/min and lower surface roughness of 1.66 μm. The SEM images showed homogeneous solidification, columnar grain structure, recast layer surface, and minor surface crack density were noticed at higher cutting conditions. The predicted model and confirmation test results were close to each other with minimum error (<5%), so the model is adequate.

Analyzing the geometrical errors of silicon nitride-titanium nitride on performing electric discharge machining using response surface methodology

Ceramic materials that find their applications in die extrusion and the balls used in bearings have a longer service life compared to that of traditional materials. Since ceramic materials are having high hardness properties, they cannot be machined traditionally, because traditional machining processes rely on the relative hardness of the tool material to the workpiece material. However, electric discharge machining aids in the machining of ceramic composites with good surface integrity performed by the copper electrodes. As a result, Spark Erosion Machining was used to investigate the geometrical tolerance of Si3N4-TiN composites. Electric discharge machining parameters range over five levels, like current from 2 to 6 A, voltage from 30 to 50 V, dielectric pressure (kg/cm2) from 16 to 24 kg/cm2, pulse on time (µs) from 15 to 19 μs, and pulse off time (µs) from 7 to 11 μs have been analyzed through an L25 orthogonal array. Main effect plots and two-dimensional and three-dimensional interaction plots have been drawn to investigate the effect of the input parameter on the output parameters like circularity, cylindricity, perpendicularity, runout, top radial overcut, and bottom radial overcut. The grey relational analysis is employed in finding the significant parameters through analysis of variance, and for each model, the regression coefficient is found. The optimal input parameters for the desired output parameters are found to be a current of 5.855 A; pulse-on time of 16.55 µs; pulse-off time of 7.22 µs; dielectric pressure of 16.32 kg/cm2; and a voltage of 40.3729 V. This research will help to enhance the geometric accuracy and precision of machined holes in Si3N4-TiN composites. The results are finally estimated using a residual data analysis, which shows that spark erosion can be improved.

Prediction of cutting forces in drilling of aluminum 6061-T6 alloy

Drilling is the most common machining operation and arguably the most crucial of the traditional machining processes. Cutting force predictions for every given set of cutting conditions are crucial for efficient product development. It has been hypothesized that the force produced during cutting is responsible for the majority of the issues seen in hole creating processes like drilling. Calculating forces accurately also aids in the development and assessment of cutting equipment and fixtures. The purpose of this article is to examine the effect of significant machining factors like thrust force and torque on the drilling operations of Aluminum 6061-T6 alloy. Theory and experiment will be compared with different types of drill bits. An average error of 5.81% was found in the Axial Force (N) and 0.85% was observed in Torque (N-cm). The error % of desired responses is found to be accepted.

Performance of magnetized tool in electrochemical micromachining on scrapped alloy wheel matrix composite

Hybrid machining processes play an important role in traditional and non-traditional machining processes. Addingthe magnetic field effect in electrochemical micromachining (ECMM) improves the machining efficiency and accuracy of the micro-hole machined. The process parameters, namely, voltage,duty cycle and electrolyte concentration,wereused as input parameters, while machining rate (MR) and overcut (OC) are performance measures considered in this research. The workpiecewasa scrapped alloy wheel matrix fabricated with a stir-casting process reinforced with alumina (Al2O3). The EDAX and SEM image study was performed to understand the composition and surface quality of the machined workpiece, respectively. The micro-hole without magnetic field effect was also conducted to under­standthe possible advantageof magnetic field appliedin ECMM.

Surface integrity of Ti-6Al-4V alloy in hybrid electrical discharge machining processes

Titanium alloy is one of the difficult-to-machine materials. The final conditions of the machined surface of this alloy are influenced by electro-discharge machining. High temperatures and thermal cycles in machining operation induce undesirable alterations in the surface quality of Ti-6Al-4V. One of the ways to improve the negative effects of electrical discharge machining is to use hybrid methods. There is no comprehensive research on the effect of hybrid electrical discharge machining process on the surface integrity of the Ti-6Al-4V alloy. In this paper, hybrid electrical discharge machining techniques including ultrasonic-assisted electrical discharge machining, powder-mixed dielectric electrical discharge machining using Al2O3 nanopowders and powder-mixed dielectric combined with ultrasonic-assisted electrical discharge machining, were used for processing of this alloy. The hybrid electrical discharge machining processes were evaluated by basic specifications of surface integrity including surface cracks, heat affected area, residual stress, and corrosion resistance. It was found that in powder-mixed dielectric combined with ultrasonic-assisted electrical discharge machining process, developed microcracks were very low and this process developed a thinner heat-altered layer, compared to traditional electrical discharge machining process, which produced a thicker heat-altered layer. The findings also, demonstrated that ultrasonic waves have reduced residual stresses compared to other methods and its stress diagram was distinct in comparison with the other processes. The corrosion rate of samples machined by electrical discharge machining process was higher than other hybrid processes; in powder-mixed dielectric electrical discharge machining process, the machined samples had the highest corrosion resistance.

A Short Review on AWJM of Natural Fibre Reinforced Composite Materials

A composite is a solid material created by combining two or more different substances, each with its own set of qualities, to create a new substance with properties that outperform the original components for a specific use. Currently composite materials are widely applied across various fields due to its superior properties. The fibre reinforced composites being light in weight, and high strength are replacing metals in many applications. Nowadays, more focus is paid in developing sustainable and environment friendly materials without compromise in the quality. This reason led to the development of Natural Fibre Reinforced Composite (NFRC) materials, which is gaining more attention towards them. Though many NFRCs were developed, machining is a very big challenge. Compared to the traditional machining processes, the non-traditional machining process is proved to be recommendable for machining NFRC materials. In this article, the numerous research endeavors carried out in machining of NFRCs using Abrasive Water Jet Machining (AWJM) process is reviewed. This article describes the different parameters considered in AWJM process and their influence over the machining characteristics of NFRCs. Based on the different research carried out, the use of nanofillers in the right composition is expected to increase the performance of the AWJM process over NFRCs.

Design and Manufacturing Semi-Automatic Machine for Battery Tray Riveting Operation

Abstract: The successful implementation of any manufacturing sector is largely depending upon the quality and its productivity. In traditional machining process for performing the one side riveting, machine’s required which becomes a time consuming also the inaccuracy in productivity due to involvement of human error which affects to productivity cannot be get improved at a faster rate. The main purpose of this project to design and manufacture semi-automatic machine for battery tray riveting. Which leads to improve the quality and productivity by minimising the time period in all Mahindra and Mahindra’s vehicles battery is fitted with the help of battery tray. While placing the battery tray two side rivets are required in current situation while fitted tray only one side riveting operation is performed. We are designing a semi-automatic machine which will perform riveting operation to both sides at once which will improve the productivity.

Electrochemical Machining Process Using Different Electrolytes for Improved Process Efficiency

Electrochemical machining (ECM) was developed as a result of the manufacturing and production industry's need to cut extremely hard alloys without leaving a troublesome layer. Manufacturing industries involved in gas turbine blades and aerospace need intricate geometries that would be difficult to make using standard methods. Because of high tool wear (TW) and metal removal rate (MRR), traditional machining processes such as milling and other conventional machining are inefficient for extracting metal from hard materials. This study outlines, a comprehensive analysis of the ECM processes using different electrolytes for better process efficiency.

An effect of process parameters during wire cut electrical discharge machining of Inconel 738

In the recent days, super alloys especially nickel based materials are used more than 50% of aerospace gas turbine components such as turbine disc, blades etc., It becomes very hard to shape these materials with the use of traditional machining processes due to its improved strength at higher temperature. To overcome the issues faced during conventional machining, the various advanced machining techniques are tried for machining these super alloys. In the present study, Inconel 738 was cut by wire electrical discharge machining using 0.25 mm diameter copper wire. Demineralized water was used as dielectric fluid between tool and workpiece electrode. During the process, voltage, wire feed rate, time of pulse on and pulse off were adjusted at four different values and totally sixteen slots were cut to analyze the machining characteristics. The machined surfaces were tested for its surface finish, rate of material removal and kerf width. The ANOVA was performed using Minitab software to find out the optimized variables and percentage contribution of each parameter in providing the influencing results. Wire feed rate was the most influencing parameter to have the lowest kerf width. As far as Material removal rate, the four parameters were had the significant impact in increasing the MRR. Voltage is the important process parameter to reduce the surface roughness.

Assessment of surface quality in extrusion honing process using dimensional analysis approach

It is critical to obtain the desired surface quality on machined parts’ internal and external portions. The estimated level of surface texture can be induced on the outer regions using traditional finish machining processes such as grinding, honing, and so on. While the problem emerges when processing miniature core components such as micro bores and inlet/outlet valves. The EH approach overcomes this limitation of the conventional finishing method. It is a novel micromachining process that extrudes pressured flow of carrier media combined with abrasives into the confined passage to generate the desired level of surface texture. Due to the abrasion process, micromachining occurs by taking away negligible stock material. The present study focus on the impact of the number of passes at the specimen’s entry and exit sides of the carrier media. The improvements in the surface finish (Ra) on both sides, i.e. entry and exit, are also evaluated. A dimensionless expression for Ra is also developed. The relation is implemented using Buckingham’s π theorem, and the developed model is compared with experimental results. SEM analysis is made to portray surface texture produced by selected

Theoretical and experimental investigations on rotary ultrasonic surface micro-machining of brittle materials

Many brittle materials, such as single-crystal materials, amorphous materials, and ceramics, are widely used in many industries such as the energy industry, aerospace industry, and biomedical industry. In recent years, there is an increasing demand for high-precision micro-machining of these brittle materials to produce precision functional parts. Traditional ultra-precision micro-machining can lead to workpiece cracking, low machined surface quality, and reduced tool life. To reduce and further solve these problems, a new micro-machining process is needed. As one of the nontraditional machining processes, rotary ultrasonic machining is an effective method to reduce the issues generated by traditional machining processes of brittle materials. Therefore, rotary ultrasonic micro-machining (RUμM) is investigated to conduct the surface micro-machining of brittle materials. Due to the small diameter cutting tool (<500 μm) and high accuracy requirements, the impact of input parameters in the rotary ultrasonic surface micro-machining (RUSμM) process on tool deformation and cutting quality is extremely different from that in rotary ultrasonic surface machining (RUSM) with relatively large diameter cutting tool (∼10 mm). Up till now, there is still no investigation on the effects of ultrasonic vibration (UV) and input variables (such as tool rotation speed and depth of cut) on cutting force and machined surface quality in RUSμM of brittle materials. To fill this knowledge gap, rotary ultrasonic surface micro-machining of the silicon wafer (one of the most versatile brittle materials) was conducted in this study. The effects of ultrasonic vibration, tool rotation speed, and depth of cut on tool trajectory, material removal rate (MRR), cutting force, cutting surface quality, and residual stress were investigated. Results show that the ultrasonic vibration could reduce the cutting force, improve the cutting surface quality, and suppress the residual compressive stress, especially under conditions with high tool rotation speed.

Smart Manufacturing through Machine Learning: A Review, Perspective, and Future Directions to the Machining Industry

Nowadays, to reach progressive growth although being competitive in the market, the manufacturing industries are using advanced technologies such as cloud computing, the Internet of things (IoT), artificial intelligence, 3D printer, nanotechnology, cryogenics, robotics, and automation in smart manufacturing sectors. One such subclass of artificial intelligence is machine learning, which uses a computer system for making predictions and performing definite tasks without any use of specific instructions to enhance the quality of the product, and rate of production, and to optimize the processes and parameters in machining operations. A broad category of manufacturing that is technology-driven utilizes internet-connected machines to monitor the performances of manufacturing processes referring as smart manufacturing. The current paper presents a comprehensive survey and summary of different machine learning algorithms which are being employed in various traditional and nontraditional machining processes, and also, an outlook of the manufacturing paradigm is presented. Subsequently, future directions in the machining industry were proposed based on trends and challenges that are accompanying machine learning.

Experimental study on laser assisted ultrasonic elliptical vibration turning (LA-UEVT) of 70% SiCp/Al composites

SiCp/Al composites are more and more used in aerospace, military industry and other industries. However, the surface integrity of materials is poor, and the cutting force is large as the anisotropy of materials in the traditional machining (TM) process, which hinders the application of ceramic particle reinforced metal matrix composites. With the requirement of high dimensional accuracy, high efficiency and low damage for materials in these fields, non-traditional machining technology has become a research hotspot. Laser assisted machining (LAM) is a non-contact special machining method. Its advantages in machining SiCp/Al composites have been proved by experiments, but there are still processing defects such as thermal cracks. Therefore, to further improve the machining quality of 70% SiCp/Al composites with high volume fraction, a new machining method combining ultrasonic elliptical vibration turning (UEVT) and laser heating assisted turning (LAT) is proposed. High frequency intermittent machining and the adjustment of laser temperature influence on materials can be realized by adjusting the ultrasonic amplitude. Combining the characteristics of the two processing techniques, the feasibility study of the new machining method was studied by turning experiments. In this paper, compared with TM and LAT, the removal mechanism of materials and the effects of different laser heating temperatures and ultrasonic vibration on cutting force, surface quality, subsurface damage and chip morphology are explored. The results show that LA-UEVT can effectively reduce the cutting force and surface roughness, improve the plastic removal ability, and inhibit surface and subsurface damage. And the material removal process is mainly in the form of small particle crushing and particle pressing, which improves the stability of cutting force in the cutting process.