Wet Machining Research Articles

Comparative study of parametric influence on wet and dry machining of LM 25 aluminium alloy

Aluminium – silicon alloys are most frequently adopted for numerous engineering applications such as automobile, marine and aircraft manufacturing industries due to its high strength to weight ratio. Turning is considered as one of the most important machining processes for producing components of desired shape with dimensional accuracy. Manufacturing processes influences the functional performance of the components. This present article discuss about the optimization of machining parameters in turning LM 25 aluminium alloy in wet and dry environments. The parameters considered for machining are cutting speed, feed and depth of cut with the performance measures as surface roughness, material removal rate and cylindricity error. Taguchi’s L9 orthogonal array was employed for conducting the experiments. The parameters are optimized simultaneously by Grey Relational Analysis (GRA) method. The impact of the machining parameters on performance measures were compared on both wet and dry machining environments.

Surface Behavior of AISI H13 Alloy Steel Machining under Environmentally Friendly Cryogenic MQL with PVD-Coated Tool

Abstract Cooling and lubrication throughout the machining process have a vital impact on final product quality. Use of cutting fluid in the machining process will not control the increased heat generation that is due to frictional resistance, conventionally. Cryogenic machining along with minimum quantity lubrication (CMQL) is a reliable choice to flood cooling in pertinence. It averts the utilization of a large amount of cutting oil and it improves surface integrity. Carbon dioxide provides better cooling to the tool and work material. Additionally, the vegetable oil droplets provide better lubrication at the interface. The investigation results on the response of CMQL on machinability of AISI H13 steel with varying cutting speeds in the range of 45–75 m/min in end milling uses a PVD-AlTiN–coated carbide insert at a constant depth of cut. Machining with CMQL gives 52–53 % and 38–41 %, 65–71 %, and 33–41 % on cutting temperature and surface roughness, respectively, which is a dwindling value when interrelated with dry and flooded cooling environments, in which cutting forces and flank wear were subsequently reduced moderately when compared to dry and wet machining. Application of CMQL provides exceptional lubrication and cooling to the cutting zone.

Modelling for cost and productivity optimisation in sustainable manufacturing: a case of dry versus wet machining of mould steels

Under certain conditions, dry machining has been known to offer improved efficiency. To determine the effectiveness of dry machining in the production of steel, it is necessary to identify optimal machinability conditions for commonly used mould steel products and their economic aspects. The present study expands on a comparative analysis of dry and wet optimum machinability conditions for universally used industrial mould steels; SF-5, SF-2312, SF-2-000, and SP-300. In this study, the newly developed MICO (Machining Inventory and Cost Optimisation) tool was used to determine the machining related production cost and identify optimal productivity parameters for these mould steels. The MICO analysis presented utilised the established tool wear equations for both dry and wet milling conditions to determine machining costs and productivity. The results of the case study revealed that during dry machining, materials with lower-hardness steels (SF-5 and SF-2312) saw increased productivity and a reduction of total costs with optimal conditions. In wet milling operations, the added use of lubrication increased costs by 5–8% at optimal machining conditions. The overall cost was found to be more sensitive to the influence of lubrication than were the tool usage and inventory costs.

Experimental investigation and sustainability assessment to evaluate environmentally clean machining of 15-5 PH stainless steel

This paper aims to present the environmental issues associated with conventional cutting fluids strategy and find out alternative solutions in terms of environmentally friendly cooling and lubrication techniques with high machining performance. In this view, this paper analyses the cleaner cooling and lubrication techniques, namely dry, MQL, and cryogenic machining with conventional lubrication technique, namely wet machining to reduce the usage of non-renewable energy source and recycle process without losing the productivity. In this context, cutting force, co-efficient of friction (CoF), energy consumption, surface roughness parameters and chip reduction coefficient (CRC) are measured for dry, wet, MQL, and cryogenic machining of 15−5 Precipitation Hardened Stainless Steel (PHSS) with variation in cutting speed and feed rate. Also, a previously applied sustainability assessment algorithm has been implemented to study the effectiveness of these cooling and lubrication strategies. The sustainability assessment includes machining performance as well as sustainable indicators (i.e., waste management, environmental impact as well as operational health and safety) in a single integrated analysis to achieve a balance between the machining efficiency and sustainability effectiveness. At higher value of cutting speed (199 m/min) and feed rate (0.333 mm/rev), 29.26 %, 52.68 % and 53.33 % increment in the value of cutting force were observed in dry, wet and MQL machining in comparison with cryogenic machining respectively. The higher values of CoF and CRC found in dry machining suggest more friction and amount of plastic deformation respectively as compared to other cutting fluid strategies. The 6.27 % higher value of energy consumption was observed in dry machining as compared to other cutting environments. At higher cutting parameters, in cryogenic machining, 6.76 %, 1.8 % and 26.62 % lower surface roughness (Ra) were observed as compared to dry, wet and MQL machining, respectively.

Experimental investigation of the effect of tool material on the performance of AISI 4140 steel in the rotary near dry electrical discharge machining

This research conducts in three sections. The first section studies the effect of tool materials and gases on rotary workpiece electrical discharge machining. During the experiments, the effects of three kinds of tool materials (Cu, Cu-Cr, and Cu-Sn) and three types of industrial gases (air, argon, and CO2) on the material removal rate, tool wear rate, and workpiece surface roughness are investigated. The second is a comparison between rotary workpiece, rotary tool, and the fixed workpiece by choosing the appropriate tool material and gas in order to observe the effect of workpieces rotation on the process. Finally, another comparison has been done between wet electrical discharge machining and near dry electrical discharge machining of the fixed workpiece in order to study the effect of the dielectric. The results show the copper tool has the best performance compared with other tools. Scanning electron microscopy output shows the Cu-Sn tool creates shallow micro-cracks on the surface. Air and CO2 gases have the higher material removal rate in low current, but argon has better function than other gases in high current. In addition, a rotational speed causes an increase in material removal rate and tool wear rate and surface roughness decrease in near dry electrical discharge machining. The level of tool wear rate has decreased by 14% in the rotary workpiece compared with the rotary tool.

Experimental investigations on the applicability of solid lubricants in processing of AISI 4140 steel

Machining of material is the most versatile and precise process because of its various application in manufacturing industries. As the result of shear deformation of workpiece, lot of heat is generated in machining. Cutting fluids are used to reduce the effects of heat generated during machining. However, at very high temperature and pressure conditions liquid become volatile and losses its properties. Also, these cutting fluids are not eco-friendly and these are hazardous to health. Solid lubricants having ability to with stand very high pressure and temperature can be utilized to improve the machining by reducing the friction co-efficient at tool-work interface. Hence, present study aims to investigate the applicability of solid lubricant in machining of AISI 4140 steel. An experimental setup has been developed to supply the solid lubricant in machining and machining performance is studied under dry, flood cooling and solid lubricant assisted machining. Comparison of results showed considerable improvement in surface quality, decrease in power requirement and also reduction in tangential force with solid lubricants compared to dry and wet machining process.

Effect of edge preparation technologies on cutting edge properties and tool performance

Edge preparation has gained widespread use due to its low cost and high impact. Various edge preparation methods are reported in the literature. Choice of edge preparation techniques influences the edge properties and the ensuing tool performance. The current work investigates the influence of three different edge preparation methods, brushing, drag finishing, and wet abrasive jet machining on the performance of tungsten carbide inserts during orthogonal turning. Edge preparation not only changes the geometry but also the properties of the edge. Experimental results show that a drag finished edge has the lowest edge surface roughness (Ra = 0.42 μm), while abrasive jet machining can induce 63% greater compressive residual stress than the unprepared tool. Reduction in tool wear was observed at the same stage of cutting length in the prepared edges alongside improved edge hardness. A thermomechanical finite element analysis is performed to evaluate the thermomechanical behavior of all the cutting edges. Results demonstrate that the use of prepared cutting edges enhances stress distribution and reduces the temperature. Experimental results confirm that the drag finished edge has the best overall performance out of the three edge techniques with lower cutting temperature, better stress distribution, lower cutting forces, reduced flank wear, and reduced roughness of the machined surface finish.

The Experimental Investigation of Surface Roughness After Dry Turning of Steel S235

Abstract Nowadays lot of scientific work inspired by industry companies was done with the aim to avoid the use of cutting fluids in machining operations. The reasons were ecological and human health problems caused by the cutting fluid. The most logical solution, which can be taken to eliminate all of the problems associated with the use of cooling lubricant, is dry machining. In most cases, however, a machining operation without lubricant finds acceptance only when it is possible to guarantee that the part quality and machining times achieved in wet machining are equalled or surpassed. Surface finish has become an important indicator of quality and precision in manufacturing processes and it is considered as one of the most important parameter in industry. Today the quality of surface finish is a significant requirement for many workpieces. Thus, the choice of optimized cutting parameters is very important for controlling the required surface quality. In the present study, the influence of different machining parameters on surface roughness has been analysed. Experiments were conducted for turning, as it is the most frequently used machining process in machine industry. All these parameters have been studied in terms of depth of cut (ap), feed rate (f) and cutting speed (vc). As workpiece, material steel S235 has been selected. This work presents results of research done during turning realised on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process results.

Towards sustainable machining of 17-4 PH stainless steel using hybrid MQL-hot turning process

The use of a minimum quantity of lubrication (MQL) with extremely low consumption of lubricant in machining processes has been reported as a technologically and environmentally feasible alternative to conventional flood cooling. In hot machining, the external heat source is applied during machining that will assist to increase machining performance. Many external heating techniques are available and each type has advantages/disadvantages. 17-4 PH stainless steel (AISI630) is martensitic stainless steel, which is widely used in energy equipment, aerospace and petrochemical industries. The objective of the present paper is to integrate MQL technique, for the first time, with a hot turning process for finding an optimum possible hybrid technique for a particular machining process. The effects of different machining parameters on MQL turning of 17-4 PH stainless steel have been investigated in comparison with dry and wet machining processes. Experiments were also designed for machining using MQL and dry techniques to evaluate surface roughness, tool wear, machined surface morphology, chip morphology as well as chip formation mechanism under different pre-heating temperatures. The results show that applying MQL technique with online thermally enhanced turning (MQL-hot turning) increases the efficiency of machining of 17-4 PH stainless steel. The cutting parameters and pre-heating temperature are important parameters and should be selected carefully when using hybrid MQL-hot turning. In addition, machining with MQL is beneficial to the environment and machine tool operator health as lubricant consumption during operation with MQL is 7-fold lower than in the conventional system.

Impact on Machining of AISI H13 Steel Using Coated Carbide Tool under Vegetable Oil Minimum Quantity Lubrication

Abstract In machining, final surface quality and dimensional accuracy are the most specified customer requirements. AISI H13 tool steel is used in many fields such as the automotive, aerospace, and defense fields. It is considered to be a hard-to-machine material because of its immense strength. Conventional machining has several negative effects for the environment and human health. It has failed to produce a superior performance on machining of H13 steel. In this study, an eco-friendly minimum quantity lubrication technique is implemented by using a commercially available vegetable-based cutting fluid. An investigation was done on surface characteristics, chip morphology, and intensity of cutting temperature evolved during the machining of H13 steel. Further, wear on the tool of PVD-titanium-aluminum-nitrogen/titanium-nitrogen–coated carbide inserts used for milling was observed for the given input cutting speeds of 30, 45, 60, and 75 m/min and feed rates of 0.08, 1, and 1.2 mm/rev for the constant depth of cut of 1 mm. The results obtained from vegetable oil–based minimum quantity lubrication showed a reduction in the cutting temperature by 52–57 % and 38–45 % and the average surface roughness in the range of 53–64 % and 22–40 % compared to dry and wet machining.

Effects on tool performance of cutting edge prepared by pressurized air wet abrasive jet machining (PAWAJM)

Abstract Edge preparation techniques are used to shape a proper edge microgeometry for enhanced tool performance. However, depending on the edge preparation method, the edge properties are also altered. Most of the reported work is limited to the effect of edge micro-geometry. In this paper, cutting edges prepared by pressurized air wet abrasive jet machining (PAWAJM) were evaluated from several aspects including tool edge geometries, tool surface quality and topographies, edge hardness (H) and residual stresses. Furthermore, the influence of the prepared edge on the tool performance of uncoated tungsten carbide cutting inserts with different average cutting edge rounding ( S ¯ ) as well as different form factor (K) were experimentally investigated through the orthogonal turning of AISI 4140 alloy steel. Results show that the performance of the prepared cutting edge depends on the combined effect of the initial state of edge geometry and edge properties For symmetric edges (form factor K = 1), the optimum range for average cutting edge rounding ( S ¯ ) was found to be 20 μm to 30 μm when using cemented carbide tools for dry machining AISI 4140 steel at a feed rate (f) =0.1 mm/rev, width of cut = 3 mm, and cutting speed (vc) = 300 m/min.

Experimental investigation of cryogenic end milling on maraging steel using cryogenically treated tungsten carbide-cobalt inserts

The cryogenic machining and cryogenic treatment have already emerged as the sustainable manufacturing process of the future generation. The cryogenic treatment improves the cutting tool life, but the high cutting temperature developed during high-speed machining reduces the effect of cryogenic treatment of cutting tool. This study investigates the possible improvements in cutting tool life by combining cryogenic cooling and cryogenic treatment. The authors believe that these two techniques can replace conventional machining approaches using dry and wet machining conditions using coated carbide tools. The tungsten carbide-cobalt inserts are cryogenically treated (CT) at a soaking temperature of − 195.8 °C for a period of 24 h and are used to evaluate milling performance under dry, wet, and cryogenic cutting environments. The machining experiments are conducted on maraging steel MDN 250 using one factor at a time approach by varying spindle speed and keeping feed rate and depth of cut as constant. The cutting force, surface roughness, tool wear, and subsurface microhardness are some of the machining responses evaluated and compared with an untreated cutting tool (UT). The tool life improved up to 24% during cryogenic machining using CT tools at a spindle speed of 270 rpm.

COMPLEXITY-BASED ANALYSIS OF THE INFLUENCE OF MACHINING PARAMETERS ON THE SURFACE FINISH OF DRILLED HOLES IN DRILLING OPERATION

Drilling is a famous and widely used machining operation to make holes in the workpiece. The size and surface quality of drilled hole are two factors that should be considered mainly. In this research, we examine the effect of different machining parameters and conditions on the surface quality of generated hole in drilling operation. For this purpose, we employ fractal theory and investigate how the variations of depth of cut and spindle speed affect the complexity of surface texture of drilled holes in wet and dry machining conditions. Based on the obtained results, the increment of depth of cut and spindle speed in case of wet and dry machining causes lower complexity on the generated surface from drilling. In addition, the generated surface from dry machining is more complex than the generated surface from wet machining. The obtained method in this research can be applied to other machining operations in order to investigate the effect of machining parameters and conditions on the surface quality of machined workpiece.

COMPLEXITY-BASED DECODING OF THE EFFECT OF MACHINING PARAMETERS ON THE MACHINED SURFACE IN MILLING OPERATION

Acquiring the desired surface quality is one of the major efforts in machining of materials. Milling operation is a widely used machining operation to shape the material in different forms. Machining parameters and conditions are two major factors that affect the surface quality of machined workpiece in milling operation. In this paper, we analyze the surface finish of machined workpiece under the variations of machining parameters and conditions (wet and dry conditions) in milling operation. For our analysis, we use fractal dimension as the indicator of complexity of structure. Based on the obtained results, in the case of wet machining condition, by increasing the depth of cut, feed rate and spindle speed in separate experiments, the fractal dimension of machined surface increases. However, the obtained results in the case of dry machining condition are not consistent with the variations of different machining parameters. The obtained results will be discussed in terms of complex structure of machined surface. The method of analysis employed in this research can be investigated with other machining operations to check how the machining parameters and conditions affect the surface quality of machined surface.

Effect of Machining Parameters on Tool Wear and Surface Roughness In Dry and Wet Machining of Aisi 316 Austenitic Stainless Steel by Taguchi Method

Stainless steels are widely used to manufacture mechanical components due to excellent mechanical properties. Machining is considered as one of the most critical manufacturing processes in mechanical industry to produce desired shapes and dimensional accuracy of the components. It also affects the performance of the components in its functional requirement. This paper deals with the optimization of cutting parameters in machining operation for AISI 316 austenitic steel with dry and wet environment conditions. The chosen machining parameters in this research are cutting speed, feed rate, and depth of cut as input variables, whereas the response factors are surface roughness and wear rate. Taguchi method with the L9 orthogonal array was used to analyze the process parameters based in dry and wet machining conditions. The Taguchi approach provides the best setting with lower values of surface roughness and wear rate. The regression analysis is performed to obtain a mathematical model of responses in terms of the process parameter. The composite regression optimization gives best setting for dry condition (cutting speed 173 rpm, feed 0.25 mm/rev, and 0.87 mm of the depth of cut) and for wet condition (cutting speed 173 rpm, feed 0.3 mm/rev, and 0.57 mm of the depth of cut). The results show that surface roughness and wear rate are lower in the wet environment than the dry environment.

Influence of Different Cooling Methods on Tool Life, Wear Mechanisms and Surface Roughness in the Milling of Nickel-Based Waspaloy with WC Tools

Superalloys are generally considered to be difficult to machinability. In recent attempts to facilitate their machinability, minimum quantity lubrication (MQL) has been used due to its positive influence on cutting tool life, the environment and human health. This study focused on the tool life, wear behavior and surface roughness in the milling of nickel-based superalloy Waspaloy. Uncoated carbide tools, PVD (TiAlN)-coated tools and CVD (TiCN + Al2O3 + TiN)-coated tools were used. Experiments were performed with different cooling methods which included dry, wet and MQL. SEM and EDX were used for tool wear behavior and mechanism analyses. A portable measuring instrument and a 3D optical profilometer were employed for surface roughness analyses. Results obtained from the tests showed that during the milling of the Waspaloy, adhesion and abrasion were effective wear mechanisms for the cutting tools. The main wear behaviors were flank wear, crater wear and BUE (built up edge). In addition to these results, reduction in the tool wear, the wet machining and machining with the MQL system provided improvement at the rates of 37.54% and 29.01%, respectively, when compared to the dry machining.

DECODING OF THE RELATION BETWEEN FRACTAL STRUCTURE OF CUTTING FORCE AND SURFACE ROUGHNESS OF MACHINED WORKPIECE IN END MILLING OPERATION

Analysis of the surface quality of workpiece is one of the major works in machining operations. Variations of cutting force is an important factor that highly affects the quality of machined workpiece during operation. Therefore, investigating about the variations of cutting forces is very important in machining operation. In this paper, we employ fractal analysis in order to investigate the relation between complex structure of cutting force and surface roughness of machined surface in end milling operation. We run the machining operation in different conditions in which cutting depths, type of cutting tool (serrated versus square end mills) and machining conditions (wet and dry machining) change. Based on the obtained results, we observed the relation between complexity of cutting force and surface roughness of generated surface of machined workpiece due to engagement with the flute surface of end mill, in case of using square end mill in dry machining condition, and also in case of using serrated end mill in wet machining condition. The fractal approach that was employed in this research can be potentially examined in case of other machining operations in order to investigate the possible relation between complex structure of cutting force and surface quality of machined workpiece.

Performance Analysis of Machining Ti–6Al–4V Under Cryogenic CO2 Using PVD-TiN Coated Tool

Demand for titanium alloys in different sectors is increasing in recent years due to their outstanding strength-to-weight ratio, ability to retain strength at higher temperatures and resistance to wear. Machining of titanium Ti–6Al–4V has an adverse influence from the premature failure of the tool. Conventional cooling technique fails to reduce the temperature generated at the cutting area attributed to poor surface quality. Liquid carbon dioxide (LCO2) as a cryogenic coolant has turned into a recent trend in machining as it does not require any expensive method of disposal. This experiment investigates the performance of cryogenic cooling technique in the end milling of Ti–6Al–4V using PVD-TiN-coated tool with a different speed-feed combination. The angle of the nozzle was maintained 45° in the feed direction. The results demonstrated that machining with LCO2 lowers the cutting temperature by 39.53–57.44% and surface roughness by 48.24–74.77% compared with wet machining. The impact of utilizing LCO2 as a cryogenic coolant improved the surface and subsurface characteristics.

FRACTAL-BASED ANALYSIS OF THE EFFECT OF MACHINING PARAMETERS ON SURFACE FINISH OF WORKPIECE IN TURNING OPERATION

Analysis of workpiece surface quality is one of the major issues in manufacturing engineering. Turning operation is a famous machining operation that is widely used in machining of materials. In this research, we investigate the surface finish of machined workpiece from turning operation. For this purpose, we employ fractal theory to study the complex structure of machined workpiece’s surface in different conditions. The applied parameters include the variations of cutting depth, feed rate and spindle speed in wet and dry machining conditions. Based on the obtained results, we found the correlation between the increment of fractal dimension of machined surface and the increment of cutting depth, feed rate and spindle speed in wet machining condition. The obtained results will be discussed in relation with the complexity of machined surface. The employed method of analysis in this research can be widely applied to the analysis of the effect of different machining parameters and conditions on the surface quality of machined workpiece in case of different machining operations.

Investigation on cutting edge preparation and FEM assisted optimization of the cutting edge micro shape for machining of nickel-base alloy

The productivity and the tool life of cutting tools are majorly influenced by the cutting edge micro shape. The identification of optimized cutting edges is usually based on empirical knowledge or is carried out in iterative investigation steps. This paper presents an approach to predict optimal cutting edge micro shapes with the aid of finite-element-simulations of the chip formation. The approach is investigated for the machining of the nickel-base alloy Inconel 718. The cutting edges are prepared by pressurized air wet abrasive jet machining. Utilizing this method, the prepared cutting edges have a certain profile, which is considered for the modelling. By applying a model for tool wear the influence of the cutting edge micro shape on the tool life span is estimated. Subsequently, a statistical modelling provides the prediction of the tool wear rate for any possible parameter set within the investigated range. This is used to find an optimized cutting edge profile that minimizes the tool wear. An experimental investigation concludes the optimization procedure.