Quality Of Machined Components Research Articles

Elevating Sustainability: The Role of Machining in Modern Eco-Friendly Manufacturing Processes

Sustainable manufacturing has become a critical concern across various industries, including aerospace, automotive, and services. It involves the creation of manufactured products through economically sound processes that minimize negative environmental impacts while conserving energy and natural resources. Additionally, sustainable manufacturing aims to enhance employee, community, and product safety.This paper focuses on the machining process as a key component of sustainable manufacturing. Machining is widely used in manufacturing industries to fabricate components, but it also significantly contributes to environmental pollution. Sustainable machining has been a topic of discussion for over a decade. In sustainable machining processes, every factor acts differently like, the tool life, productivity, and effective utilization of resources must be increased. In contrast, the machining cost, machine cutting power, and adverse effect of cooling and lubrication fluids will be decreased. Important aspects of sustainable machining include dry and near-dry machining, cryogenic machining, and minimum quantity lubricant (MQL) were presented in this article. The effectiveness of these processes is assessed based on cutting tool life and the quality of machined components. In addition, the advancements consideration such as novel process variations, process hybridization, the use of sustainable tools and green transfer mediums, and the optimization of process parameters. Recommendations include increasing efficiency and reducing waste by incorporating recyclable tools in the machine industry implementing either stand alone or hybrid sustainable lubrication machining techniques.

Comparative Analysis of Face Milling in Dry and Wet Condition of Al 8011 For Minimum Surface Roughness in Face Milling

Abstract: The quality of machined components is evaluated in respect of how closely they adhere to set product finish, and reflective properties. Dimensional accuracy, tool wear and quality of surface finish are three factors that manufacturers must be able to control at the machining operations to ensure better performance and service life of engineering component. Aluminum alloys are extensively used as a main engineering material in various industries such as automotive industries, the mould and the die components manufacture and the industry in which weight is the most important factor. The purpose of this research is to investigate the effect of the main factors of the surface roughness and flatness in aluminum 8011 face milling with dry and wet condition. This experimental investigation to be conducted by using VMC controlled milling machine with 30mm face milling cutter with carbide multiple inserts. The same parameters were executed during the operation only difference minimum quantity lubricant for one set of operation and another set of operation without lubricant. The experimental results were evaluated using Taguchi technique minimum surface finish obtained at medium speed and maximum feed and depth of cut 0.222 µm in the dry condition during the face milling operation. The minimum flatness was obtained 0.012 mm at wet condition. minimum surface finish obtained through dry condition. Optimal control factor and ANNOVA calculations were found for face milling operation of AA8011.

A Hybrid Approach of NSGA-II and TOPSIS for Minimizing Vibration and Surface Roughness in Machining process

Increasing vibration amplitude during end milling process can seriously affect the life of end mills and reduces surface finish. Spindle and worktable vibration has a significant influence on surface quality of machined components. This paper confronts and investigates the effect of machining and geometrical parameters (spindle speed, feed rate, axial depth of cut, radial depth of cut and radial rake angle) on spindle and worktable vibration in terms of acceleration amplitude and surface roughness. Experiments were conducted on aluminium alloy 6061-T6 with high-speed steel (HSS) end mill cutter based on the central composite design (CCD). Response surface methodology (RSM) was used to develop the predictive models and the adequacy of the models were verified using analysis of variance (ANOVA). Non-dominated sorting of genetic algorithm (NSGA-II) was adopted to solve the multi objective optimisation problem and the optimised results were resulted with a set of Pareto-optimal solutions. The multi criteria decision making method (MCDM) such as technique for order preference by similarity to ideal solution (TOPSIS) and analytical hierarchy process (AHP) were designed to rank the Pareto optimal solutions based on response of closeness coefficient values.

Turning by electrical discharge machining: A review

Turning by electrical discharge machining is an emerging area of research. Generally, wire-cut electrical discharge machining is used for turning because it is not concerned with electrode tooling cost. The process variant die-sinking electrical discharge machining can also be effectively used to generate free-form cylindrical geometries on difficult-to-cut materials with complex shapes at both macro and micro levels. The machining performance of electric discharge machine is defined and influenced by its process parameters, which significantly affects production rate and the quality of machined component. Thus, it is very important to select machining parameters and their levels cautiously in order to improve the outcome of the process. In this article, the authors have reviewed the research work carried out in the area of electrical discharge turning in the last decade for the improvement of material removal rate, surface integrity and roundness. In this review, various techniques reported by electrical discharge machining researchers on turning have been categorised in different electrical discharge machining variants. The article also discussed the future direction of research work in the same area.

Finite element modeling of microstructural changes in Waspaloy dry machining

It has been well documented in the literature the importance of strict surface integrity checks upon performance and quality of machined components, especially for the safety critical components (e.g., aerospace) that work at cyclic high mechanical loads and elevated temperatures. In this field, Waspaloy, within the commercially available nickel-based superalloys, is extensively applied in different industries such as aircraft, chemical plant equipment, and petrochemical equipment. The main objective of this paper is to implement a reliable FE model, for dry orthogonal machining of Waspaloy, capable to predict microstructural changes and dynamic recrystallization during the cutting process. A user subroutine was implemented in FE code to simulate the dynamic recrystallization and consequently grain refinement and hardness variation on the machined surface and below it. Zener–Hollomon (Z-H) and Hall–Petch (H-P) equations were employed to, respectively, predict grain size and microhardness. In addition, depth of the affected layer was controlled using the critical strain equation. FE numerical model was properly calibrated using an iterative procedure based on the comparison between simulated and experimental results. Finally, very good agreement was found between experimental and simulated results of grain size, microhardness, depth of the affected layer, and other fundamental variables such as cutting forces, temperature, and chip morphology.

New Generation Geometrical Product Specification (GPS) Backed Flatness Error Estimation and Uncertainty Analysis

Measurement and verification are one of the prime stages in the entire course of geometrical products in new generation of geometrical product specifications (GPS) standard. Like other kinds of form tolerances, flatness error is one of the important characteristics affecting the functionality and quality of machined components; sufficient efforts have long been made to determine the flatness error close to the true value based on the minimum zone method (MZM) and still needs continual improvement. This paper presents real coded genetic algorithms referred as Efficient Genetic Algorithms (EGA) for flatness error based on minimum zone method having good precision, repeatability and fast convergence rate. This paper also presents evaluation procedure for measurement uncertainty in flatness error based on new generation geometrical product specifications (GPS). Uncertainty in flatness error has been determined and evaluation procedure is provided to prove the conformance or non-conformance by taking into account the uncertainty in measurement. The contributing factors in measurement uncertainties have been identified and then quantified. The flatness error and evaluation theory in this paper are in the framework of new generation GPS standard. Two practical examples have been presented to show the effectiveness of EGA and shed some light on the uncertainty evaluation theory based on new generation GPS standard.

Surface Roughness Prediction in Grinding: a Probabilistic Approach

Surface quality of machined components is one of the most important criteria for the assessment of grinding processes. The importance of surface finish of a product depends upon its functional requirements. Since surface finish is governed by many factors, its experimental determination is laborious and time consuming. So the establishment of a model for the reliable prediction of surface roughness is still a key problem for grinding. In this study, a new analytical surface roughness model is developed on the basis of the stochastic nature of grinding processes. The model is governed mainly by the random geometry and the random distribution of cutting edges on the wheel surface having random grain protrusion heights. A simple relationship between the surface roughness and the chip thickness was obtained, which was validated by the experimental results using AISI 4340 steel in surface grinding.

Analysis and Prediction of Surface Integrity in Machining: A Review

Surface integrity is widely used for evaluating the quality of machined components. It has a set of various parameters which can be grouped as: (a) topography parameters such as surface roughness, textures and waviness (b) mechanical parameters such as residual stresses and hardness, and (c) metallurgical state such as microstructure, phase transformation, grain size and shape, inclusions etc. Surface roughness and residual stresses are among the most significant parameters of surface integrity, so that it is worth investigating them particularly. Many factors affect the surface integrity of machined components, including cutting parameters, tool parameters, material properties and vibrations. We can make prediction and optimization for surface integrity by taking advantage of these factors. This paper reviews previous studies and gives a comprehensive summary of surface integrity in the following order: introduction of surface integrity, main parameters of surface integrity, factors affecting surface integrity, prediction and optimization for surface integrity.

Evaluation of the effects of tool geometry on tool wear and surface integrity in the micro drilling process for Inconel 718 alloy

Mechanical micro machining of nickel-based super alloys is challenging due to limited tool life, but promising in terms of quality of machined component. Despite present advances in micro machining, milling and drilling tool designs still need to be tailored to specific applications. The study reported here investigated the effect of different tool geometry parameters on tool wear and workpiece surface integrity in micro drilling of nickel-based super alloy. For the cutting tests, 0.5 mm diameter twist drills were used to drill through holes on a 2.5 mm plate. Analysis of variance (ANOVA) was used to evaluate the statistical significance of drill point angle and helix angle and their interactions on tool wear and burr size. Burr formation mechanism was investigated supported by material microstructure evaluations. The results show that a complex relationship (interaction) exists between point angle and helix angle which drive tool wear, burr formation and surface and subsurface deformations. An optimum value of 150° point angle and 40° helix angle results in reduced tool wear rate, burr formation and subsurface plastic deformation. The results also show that subsurface deformation is influenced by the size effect. The study defines the significance of tool geometry on the micro drilling performance for nickel-based super alloys.

New tool-workpiece setting up technology for micro-milling

A major issue in micromilling is the setting up with the necessary accuracy the work coordinate system on the machine. The spindle thermal stability during the setting up procedure make this a very difficult task. Thus, it is essential to develop new tool setting up technology to increase the process productivity, reduce machine setting up times and errors, and at the same time improve the precision and quality of machined components. The paper presents a cost-effective and reliable method for setting up the work coordinate system for micro-milling operations employing an on-line tool–workpiece voltage monitoring system. The viability of the proposed method was verified in a series of experiments conducted on an ultra-precision micromilling machine centre. The experimental trials involved the machining of test parts in brass with cutters 100 and 200 µm in diameter. The results of these experiments were analysed and compared with the capabilities of currently available methods and technologies on micro milling machine tools for condition monitoring and setting up the working coordinate systems. Finally, conclusions are made about the effectiveness of the proposed new tool-workpiece setting up technology for micro milling.

Analysis of surface integrity for minimum quantity lubricant—MQL in grinding

The quality of machined components is currently of high interest, for the market demands mechanical components of increasingly high performance, not only from the standpoint of functionality but also from that of safety. Components produced through operations involving the removal of material display surface irregularities resulting not only from the action of the tool itself, but also from other factors that contribute to their superficial texture. This texture can exert a decisive influence on the application and performance of the machined component. This article analyzes the behavior of the minimum quantity lubricant (MQL) technique and compares it with the conventional cooling method. To this end, an optimized fluid application method was devised using a specially designed nozzle, by the authors, through which a minimum amount of oil is sprayed in a compressed air flow, thus meeting environmental requirements. This paper, therefore, explores and discusses the concept of the MQL in the grinding process. The performance of the MQL technique in the grinding process was evaluated based on an analysis of the surface integrity (roughness, residual stress, microstructure and microhardness). The results presented here are expected to lead to technological and ecological gains in the grinding process using MQL.

New Methods for Tool Failure Detection in Micromilling

A major issue in micromilling is unpredictable tool life and premature tool failure. The specific acoustic footprint and very small removal rates during machining as well as the use of small diameter cutters makes the detection of tool breakage a very difficult task. Thus, it is essential to develop new tool monitoring systems to increase the process productivity, reduce machining costs, and at the same time improve the precision and quality of machined components. This paper analyses three cost-effective and reliable methods for tool breakage detection: an on-line laser system, an on-line tool-workpiece voltage monitoring system, and a programming solution employing an off-line laser system. In order to verify the capability of these three methods, a series of experiments were conducted on an ultra-precision micromilling machine. This involved the machining of test parts in brass, aluminium, steel, and polymethylmethacryate (PMMA) with cutters from 0.5 mm down to 0.1 mm in diameter. The results of these tests are analysed and the technological capabilities of the three studied monitoring approaches are then compared. In addition, the possibility of developing an integrated solution that combines the capabilities of these three monitoring methods is discussed and conclusions made about the feasibility of such an approach.

Grinding of silicon carbide with diamond wheel (Influence of grinding condition on the quality of ground components)

Among various kinds of ceramics SiC has excellent properties as the material for mechanical components. From this point of view, generations of cracks and chipping of workpiece during grinding process are serious problems. They have remarkable adverse effects on the strength of machined components. In this study, experiments are carried out to clarify the influence of grinding condition on the quality of machined components. Reaction bonded as well as sintered SiC are ground with diamond wheels, Special attention is paid to relation between the strength of ground components and their surface roughness. Results obtained in this study provide useful informations to determine grinding condition.