Possibility of Reducing Environmental Load in Hard Machining

2011 ◽  
Vol 496 ◽  
pp. 205-210 ◽  
Author(s):  
János Kundrák ◽  
Gyula Varga
Keyword(s):  
Economic Efficiency ◽  
Hard Turning ◽  
Machining Process ◽  
Hard Machining ◽  
Environmental Load ◽  
Production Engineering ◽  
Environmental Aspects ◽  
Machining Processes ◽  
Metal Machining ◽  
Technical Possibility

Abstract. The development of metal machining processes and procedures has been characterized by aiming at accuracy and economy for decades. The applied coolants and lubricants helped this process; however, they are polluting the environment. For today that is a social demand and technical possibility that environmental aspects should predominate better in production engineering. In the frame of this article, through the application of dry hard turning we shall spotlight on its economy and efficiency. We shall prove that, keeping the same accuracy and economic efficiency, it is possible to choose a machining process by which the environmental load can be reduced compared to the most frequently applied grinding.

Some Aspects of the Hard Machining of Bore Holes

2013 ◽  
Vol 309 ◽  
pp. 126-132 ◽  
Author(s):  
János Kundrák ◽  
Gyula Varga ◽  
Istvan Deszpoth ◽  
Viktor Molnar
Keyword(s):  
Tool Life ◽  
Economic Efficiency ◽  
Hard Turning ◽  
Hard Machining ◽  
Wear Resistant ◽  
Finish Machining ◽  
Advantages And Disadvantages

The machining of hardened surfaces can be done even fulfilling the ever stricter accuracy and quality prescriptions, besides the economic efficiency. Decisively, hard machining is highlightedly important in finish processes because the components must meet increased functional demands. Therefore the number and/or the hardness of the hard surfaces on the components is continuously increasing. In practice the demand for such components is high since they are more wear resistant and their tool life may be higher. Today there are several possibilities for finish machining of components having hard surfaces. We have done experiments for hard machining of inner cylindrical surfaces. The examined procedures were as follows: grinding, hard turning, combined machining. The first two procedures (hard turning, grinding) have got different procedure-specific advantages and disadvantages. Combining these two procedures, using-up the advantages of them, the efficiency of the production can be increased. This paper outlines these procedures of hard machining, their applicability, the increase of their efficiency, and the possibilities provided by the combination of the procedures.

Improving Milling Performance with High Pressure Waterjet Assisted Cooling / Lubrication

1995 ◽  
Vol 117 (3) ◽  
pp. 331-339 ◽  
Author(s):  
R. Kovacevic ◽  
C. Cherukuthota ◽  
R. Mohan
Keyword(s):  
High Pressure ◽  
Metal Removal ◽  
Removal Rate ◽  
Water Pressure ◽  
Surface Profile ◽  
Machining Process ◽  
Orifice Diameter ◽  
Machining Processes ◽  
Milling Performance ◽  
Metal Machining

During machining, due to relative motion between tool and workpiece, severe thermal/frictional conditions exist at the tool-chip interface. Metal machining processes can be more efficient in terms of increasing the metal removal rate and lengthening tool life, if the thermal/frictional conditions are controlled effectively. A high pressure waterjet assisted coolant/lubricant system that can be used in conjunction with rotary tools (e.g., face milling) is developed here. The performance of this system is evaluated in terms of cutting force, surface quality, tool wear, and chip shape. The improvement in the effectiveness of the developed system with increase in water pressure and orifice diameter is also investigated. Stochastic modeling of the surface profile is performed to obtain more information about the role of waterjet in the machining process.

Methods for Improving Chucking Accuracy

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Jeongmin Byun ◽  
C. Richard Liu
Keyword(s):  
Hard Turning ◽  
Machining Process ◽  
Machining Processes ◽  
Positioning Accuracy ◽  
Major Bottleneck ◽  
Series Of Experiments ◽  
Finish Hard Turning ◽  
Major Factors ◽  
Finishing Processes ◽  
Accuracy And Repeatability

Since recent studies have demonstrated the benefits of hard turning over other abrasive machining processes as a finishing process in terms of surface integrity, a strong need has existed to improve the performance of chucking. It is because the poor repeatability and accuracy in the positioning of chucked workpieces became the major bottleneck in the implementation of finish hard turning for precision mechanical components. However, the understanding of chucking has not been adequate nor has any systematic method been reported for improving chucking accuracy. In this paper, all the major factors that affect the positioning accuracy and repeatability of a chucked workpiece have been identified by error budgeting and systematic measurements. In addition, the characteristics of these factors as well as their effect on chucking accuracy were investigated. From the results, a chucking error map that summarizes the relations between these factors and the positioning error of a chucked workpiece was developed. Then, a series of experiments were carried out to test the effectiveness of the error budget. The results demonstrated that the knowledge on these factors was accurate and it could be effectively used to improve the positioning accuracy and repeatability of a range of cylindrical workpieces in chucking. It was also shown that hard turning alone, without any extra machining process, could satisfy the same level of concentricity, which is currently achieved by finish grinding when chucking accuracy was improved by the method developed. Even if this study was originally intended for the implementation of finish hard turning for replacing finish grinding, the methods developed in this study can be used to improve the final form accuracy of cylindrical workpieces in other finishing processes including grinding, if any work holding devices similar to chucks are used to hold the workpieces. The methodology and the procedures for improving chucking accuracy are covered in a pending patent by the authors.

scholarly journals 3D FE Modelling of Machining Forces during AISI 4140 Hard Turning

2020 ◽  
Vol 66 (7-8) ◽  
pp. 467-478 ◽  
Author(s):  
Anastasios Tzotzis ◽  
César García-Hernández ◽  
José-Luis Huertas-Talón ◽  
Panagiotis Kyratsis
Keyword(s):  
Hard Turning ◽  
Cutting Speed ◽  
Industrial Applications ◽  
Machining Process ◽  
Depth Of Cut ◽  
Machining Processes ◽  
Fe Modelling ◽  
Machining Force ◽  
Aisi 4140 ◽  
Force Components

Hard turning is one of the most used machining processes in industrial applications. This paper researches critical aspects that influence the machining process of AISI-4140 to develop a prediction model for the resultant machining force-induced during AISI-4140 hard turning, based on finite element (FE) modelling. A total of 27 turning simulation runs were carried out in order to investigate the relationship between three key parameters (cutting speed, feed rate, and depth of cut) and their effect on machining force components. The acquired numerical results were compared to experimental ones for verification purposes. Additionally, a mathematical model was established according to statistical methodologies such as the response surface methodology (RSM) and the analysis of variance (ANOVA). The plurality of the simulations yielded results in high conformity with the experimental values of the main machining force and its components. Specifically, the resultant cutting force agreement exceeded 90 % in many tests. Moreover, the verification of the adequacy of the statistical model led to an accuracy of 8.8 %.

Analysis and Fabrication of a Mechanical Quick-Stop for Research on Chip Formation in Hard Turning Process

2019 ◽  
Vol 889 ◽  
pp. 87-94
Author(s):  
Nguyen Thi Quoc Dung
Keyword(s):  
Chip Formation ◽  
Hard Turning ◽  
Manufacturing Industry ◽  
Metal Cutting ◽  
Cutting Speed ◽  
Cutting Process ◽  
Machining Process ◽  
Machining Parameters ◽  
Machining Processes ◽  
On Chip

Metal cutting is one of the most important machining processes in manufacturing industry. Thorough understanding of metal cutting process facilitates the optimization in selection of cutting tools and machining parameters. There are several methods used for studying phenomena in metal cutting process. Using a quick-top device is an efficient technique for investigation cutting process in which cutting action is stopped so suddenly that the “froze” specimen called the chip root honestly depicts what happened during cutting action. Design strategies of a quick-stop are accelerating cutting tool away from the workpiece or decelerating the workpiece remaining in engagement with the tool. Operation of a quick-stop device can be either mechanically or by explosive. Quick-stop devices can be utilized for various types of machining processes such as: turning, milling, drilling. This paper described the analysis, fabrication, and testing of a quick-stop device which is used for researching on chip formation in hard turning. This device has simple and safe operation which utilizes spring forces to retract the tool from workpiece during cutting. The results of performance at cutting speed of 283 m/min show that the separation distance is quite small, less than 0.2mm so that the deformations on the root chip are close to that while actual machining process. This indicates that the device has satisfied the requirements of an equipment for studying on chip formation.

A Review of Advances in Modeling of Conventional Machining Processes: From Merchant to the Present

2022 ◽  
pp. 1-49
Author(s):  
Shreyes Melkote ◽  
Steven Y. Liang ◽  
Tugrul Ozel ◽  
I. S. Jawahir ◽  
David A. Stephenson ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Machining Process ◽  
Future Research ◽  
Machining Processes ◽  
Research Directions ◽  
Simulation Tools ◽  
Metal Machining ◽  
Future Research Directions ◽  
Chip Geometry ◽  
Conventional Machining

Abstract This paper presents a review of recent advances in modeling and simulation of conventional metal machining processes, which continue to dominate a significant part of all machining processes, and in recent years, the need for predictive models for machining processes has grown in importance in the digital manufacturing age. Significant advances have been made in modeling the mechanics of cutting in conventional machining, driven by industrial need and enabled by rapid advances in computational power. The paper surveys the state-of-the-art in analytical and numerical modeling of conventional metal machining processes with a focus on their ability to predict useful performance attributes including chip geometry, forces, temperatures, tool wear, residual stress, and microstructure. Also included in the review is a discussion of the industrial use of modeling and simulation tools for conventional machining. Additionally, the practical applicability, implementation benefits, and methodological limitations of conventional machining process modeling have been examined. The paper concludes with a summary of future research directions in modeling and simulation of conventional metal machining processes.

Methods for Improving Chucking Accuracy

2008 ◽  
Author(s):  
Jeongmin Byun ◽  
C. R. Liu
Keyword(s):  
Hard Turning ◽  
Machining Process ◽  
Machining Processes ◽  
Positioning Accuracy ◽  
Major Bottleneck ◽  
Series Of Experiments ◽  
Finish Hard Turning ◽  
Major Factors ◽  
Finishing Processes ◽  
Accuracy And Repeatability

Since recent studies have demonstrated the benefits of hard turning over other abrasive machining processes as a finishing process in terms of surface integrity, a strong need has existed to improve the performance of chucking. It is because the poor repeatability and accuracy in the positioning of chucked workpieces became the major bottleneck in the implementation of finish hard turning for precision mechanical components. However, the understanding of chucking has not been adequate, nor has any systematic method been reported for improving chucking accuracy. In this paper, all the major factors that affect the positioning accuracy and repeatability of a chucked workpiece have been identified by error budgeting and systematic measurements. In addition, the characteristics of these factors, as well as their effect on chucking accuracy, were investigated. From the results, a chucking error map that summarizes the relations between these factors and the positioning error of a chucked workpiece was developed. Then, a series of experiments were carried out, based on the results of the earlier works to test the effectiveness of the error budget. The results demonstrated that the knowledge on these factors was accurate and it could be effectively used to improve the positioning accuracy and repeatability of a range of cylindrical workpieces chucked for machining. It was also shown that hard turning alone, without any extra machining process, could satisfy the same level of concentricity which is currently achieved by finish grinding in the machining of different types of cylindrical workpieces. Even if this study was originally intended for the implementation of finish hard turning that can replace finish grinding, the methods developed can be used to improve the final form accuracy of cylindrical workpieces in other finishing processes including grinding if any workholding devices similar to chucks are used to hold the workpieces. The methodology and the procedures for improving chucking accuracy are covered in a pending patent by the authors.

Studying The Effect of a New Mixed Cutting Fluid on Surface Roughness

2020 ◽  
Vol 38 (11A) ◽  
pp. 1593-1601
Author(s):  
Mohammed H. Shaker ◽  
Salah K. Jawad ◽  
Maan A. Tawfiq
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Cutting Parameters ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Cutting Fluids ◽  
Machining Processes ◽  
Dry Cutting ◽  
Cutting Speeds

This research studied the influence of cutting fluids and cutting parameters on the surface roughness for stainless steel worked by turning machine in dry and wet cutting cases. The work was done with different cutting speeds, and feed rates with a fixed depth of cutting. During the machining process, heat was generated and effects of higher surface roughness of work material. In this study, the effects of some cutting fluids, and dry cutting on surface roughness have been examined in turning of AISI316 stainless steel material. Sodium Lauryl Ether Sulfate (SLES) instead of other soluble oils has been used and compared to dry machining processes. Experiments have been performed at four cutting speeds (60, 95, 155, 240) m/min, feed rates (0.065, 0.08, 0.096, 0.114) mm/rev. and constant depth of cut (0.5) mm. The amount of decrease in Ra after the used suggested mixture arrived at (0.21µm), while Ra exceeded (1µm) in case of soluble oils This means the suggested mixture gave the best results of lubricating properties than other cases.

scholarly journals Temperature monitoring in the subsurface during single lip deep hole drilling

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder
Keyword(s):  
Cutting Parameters ◽  
Drill Hole ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Machining Processes ◽  
Deep Hole Drilling ◽  
Feed Force ◽  
Cutting Zone

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

scholarly journals Influence of a closed-loop controlled laser metal wire deposition process of S Al 5356 on the quality of manufactured parts before and after subsequent machining

2021 ◽  
Author(s):  
Dina Becker ◽  
Steffen Boley ◽  
Rocco Eisseler ◽  
Thomas Stehle ◽  
Hans-Christian Möhring ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Closed Loop ◽  
Deposition Process ◽  
Metal Wire ◽  
Machining Process ◽  
Machining Processes ◽  
Initial State ◽  
Additive Process ◽  
Shape Accuracy ◽  
Loop Control

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

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