Wear Surface Roughness Research Articles

Experimental research on the deep-hole boring of pure niobium tube

In the deep-hole boring process on pure niobium tube, there exist some problems including serious tool wear, tough chips, and poor surface quality. In order to bore high-quality deep holes on rolled niobium tube, the cutting tool structure and boring process parameters suitable for machining rolled niobium tube were designed and two experimental schemes were proposed. The results showed that the geometric parameters of the cutting tool and process parameters have important influences on the tool wear, chip morphologies, hole-axis deflection, and hole surface roughness. By adjusting the geometric parameters of the cutting tool and boring process parameters, reasonable geometric parameters of the cutting tool and boring process parameters were obtained.

Effects of Microstructure Evolution on Fretting Wear Behaviors of 25CrNi2MoVE Steel under Different Tempering States

Increasing load requirements and harsh operating conditions have worsened the wear of drive shafts in special field vehicles. In this paper, the evolution of the microstructure and fretting wear behaviors of 25CrNi2MoVE torsion shaft steel and their influence on the wear mechanisms were investigated as a function of tempering temperature. The results showed that the coarse grain size, low matrix hardness and non-metallic inclusions in the as-received state lead to a high wear rate and serious adhesive wear. The grain refinement after normalizing and the formed M5C2 carbide and bainite helped to improve the wear resistance and worn surface quality. Low temperature tempering is conducive to further improve the wear resistance of normalized samples, and the wear rate and worn surface roughness are increased gradually after tempering temperature increases. For quenching, although martensite structure can achieve a lower wear rate, the coefficient of friction is much higher; the wear mechanisms are primarily fatigue wear and adhesive wear. Although the adhesive wear degree and worn surface roughness were increased, the optimal anti-wear performances are obtained under tempering at 350 °C with good continuity of the surface oxide film. Excessive tempering temperature will make the softened matrix unable to form a beneficial “third-body wear”.

Feasibility of Using CeO2/Water Dielectrical Nanofluid in Electrical Discharge Machining (EDM)

Dielectrical fluids have substantial impact on the machining performance of electrical discharge machining (EDM). Apposite selection of these fluids enhances the material removal rate (MRR) and microhardness while abating the tool wear rate (TWR) and surface roughness. In the present research, feasibility of using cerium oxide/water (CeO2/water) dielectrical nanofluid in EDM is examined experimentally. A portable EDM has been employed for experimental test, whereby mild steel workpiece and pure copper tool electrode were used. Powder concentration of CeO2/water was varied from 0.0 to 2.0 g/L, while the current, set distance, depth of cut and delay time were kept constant at 0.8 A, 2.0 mm, 0.5 mm and 0.5 s, respectively. Results show that at 0.6 g/L concentration, MRR and machining efficiency is enhanced by 20.04% and 69.68%, while TWR is reduced by 29.25%. Minimum surface roughness is obtained at the concentration of 1.0 g/L with Ra value of 0.22 µm, whereas with distilled water dielectrical fluid this value is 1.06 µm. Scanning electron microscopy images confirm that the best surface quality with the least pores and minute microcracks is obtained at 0.6 g/L concentration. Use of CeO2/water dielectrical nanofluid also improved material hardness significantly. While the microhardness number with distilled water is 1.06 HV, it upraised as high as 1.94 HV at powder concentration of 0.6 g/L.

Dry machinability analyses between free cutting, resulfurized, and carbon steels

ABSTRACTFree cutting steels, also referred to as free machining steels, include free cutting additives to improve tool life and machinability. Despite their wide applications in industry, scarce information is available to ensure reliable, safe, and productive cutting operations. This work presents a comparative study of the machinability of different free cutting steels to realize their real behavior and potential as alternatives to conventional steels. Three free cutting steels (SAE 12L14, 11L17, and 11L41), a resulfurized steel (SAE 1144), and a low-carbon steel (SAE 1010) were experimentally investigated employing turning tests. Key process parameters such as wear evolution, surface roughness, and material adhesion were analyzed. The results showed that low cutting speeds tend to improve tool life in free cutting steels, while this advantage disappears at high cutting speeds. Energy-dispersive X-ray spectroscopy analyses showed that chemical elements, such as Mn, S, and, especially Pb, play a significant role in self-lubrication at the cutting tool tip, thus reducing tool wear at low and medium cutting speeds. Besides, thermal simulations were done to verify the correspondence between material properties, machinability, and thermal field in the tool/chip interface.

Experimental Investigation on Ultrasonic Atomization Assisted Turning of Titanium Alloy.

There are high cutting temperatures, large tool wear, and poor tool life in conventional machining, owing to the superior strength and low thermal conductivity of titanium alloy. In this work, ultrasonic atomization assisted turning (UAAT) of Ti6Al4V was performed with a mixed water-soluble oil-based cutting fluid, dispersed into tiny droplets by the high frequency vibration of a piezoelectric crystal. Different cutting speeds and two machining environments, dry and ultrasonic atomization assisted machining, were considered in the investigation of tool life, tool wear morphology, surface roughness, and chip morphology. In comparison with dry machining, UAAT shows lower tool wear and longer tool life due to the advantages of cooling and lubrication. Furthermore, better surface roughness, smoother chip edges, and shorter tool-chip contact length were obtained with UAAT.

Mathematical Modelling of Electric Discharge Machining of Al (6351)-SiC-B4C Hybrid Composite

The Electric Discharge Machining (EDM) has emerged as one of the major machining method for the machining of hard-to- machine materials and composites. This paper aims at creating a mathematical model for the machining of the Al(6351)-SiC-B4C composites based on the experimental data and compare the same to identify the level of errors between the mathematical model and the experimental results. This paper was aimed as an attempt to develop a mathematical model for the output parameters viz. Electrode Wear ratio and Surface roughness based on the input parameters viz. current, pulse-on-time, pulse duty-factor and gap voltage.

Wear behaviour of whisker-reinforced ceramic tools in the turning of Inconel 718 assisted by an atomized spray of solid lubricants

Atomization-based cutting fluid (ACF) is well acknowledged as an alternative to dry cutting. However, ACF is restricted to the machining of mild materials owing to higher heat generation, shearing and frictional is the principal source of the tool wear under difficult-to-cut alloys. The applicability of ACF is explored in aggressive machining by the addition of 0.2 wt% of molybdenum disulfide and graphite powder as solid lubricants in vegetable oil. The performance of whisker-reinforced ceramic tools regarding wear progression, surface roughness, and vibration analysis under dry and ACF was compared. Findings have shown 50–65% less flank wear, and 39–51% less surface roughness under ACF due to solid lubricants at a tool-chip interface that limited notching and fracture of tool edge.

A Fuzzy Modelling for Selection of Machining Parameters in Wire Electrical Discharge Machining of D2 Steel

Wire Electrical Discharge Machining (WEDM) is a widely used non-traditional machining process used for machining of hard and difficult-to-machine materials. Proper selection of machining parameters in WEDM is required for better output performance, such as Material Removal Rate (MRR), Wire Wear Rate (WWR) and Surface Roughness (SR) etc. In the present paper, Pulse ON time, Pulse OFF time, Peak Current, Spark Voltage, Wire Feed and Wire Tension were taken as the input parameters to optimize MRR, WWR and SR. A set of 27 experiments were performed as per Taguchi Design. A Fuzzy model has been proposed to select the optimum values of machining parameters. The proposed fuzzy model was found to predict the experimental values with more than 90 percent accuracy.

Electro-discharge machining of metal matrix composites - a review

Influence of reinforcement content and machining process parameters on material removal rate, electrode wear rate and surface roughness is reviewed extensively from open literature during electro-discharge machining of aluminium based metal matrix composites. Results indicate increase of reinforcement content and their particle size affects the material removal rate, electrode wear rate and surface roughness adversely. Increase in discharge current causes an increase of electrode wear rate and surface roughness. Material removal rate and electrode wear rate increase or decrease with the increase of pulse-on current and pulse-off current, which depend on material processing parameters and other machining conditions; however, surface roughness increases on increasing the pulse-on time. Increase in flushing pressure effects all the three machining quality characteristics favourably.

Optimization of Surface Topography of Electro- Discharge Machined Super Alloy Inconel 825: Using TOPSIS Integrated with Taguchi Philosophy

The aim of this research work is to find the optimum combination of input process parameters such as Peak Current(I P ), Open Voltage(V g ), Pulse-On-Time(T on ) & Duty Factor(τ) for machining of Inconel 825 on EDM using copper electrode. The experiment has been designed on 4 levels 4 factors i.e. L 16 orthogonal array. The output response parameters studied were Metal Removal Rate (MRR), Electrode Wear Rate (EWR) and Surface Roughness (R a ). During our study we have used Taguchi method to identify the proper control factors to obtain the optimum results of the process.

Material Characterization and Parametric Optimization of Unconventional Machining of TiN and TaC reinforced Stir Casted Vitallium Metal Matrix Composite

In this work, influence of machining parameters of the electro discharge machining (EDM) and Abrasive-water jet machining (AWJM) processes on the material removal rate, tool wear rate and surface roughness of the composites were investigated. Titanium nitride and tantalum carbide particles reinforced vitallium composite material was synthesized by stir casting method. The machining characteristics were analyzed through Taguchi and ANOVA methods. The Taguchi optimization technique was used to find the optimal level of parameters while the percentage of contribution for each input parameter on the responses was computed by ANOVA. Scanning electron microscope (SEM) was employed to examine the surface morphology.

Evaluation of EDM characteristics of synthesised AA2024-2 & 3 wt% SiO2 metal matrix nanocomposite (MMNC)

The present study is solely based upon the comparison of electric discharge machining (EDM) characteristics of AA2024 alloy and synthesised Aluminium metal matrix composite, fabricated with two different weight percentages of Silicon di-oxide (SiO2) as reinforcement. The experiment is performed using optimized critical parameters of EDM which affects the machining characteristics such as material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR) considerably. In this study it is observed that after the reinforcement of SiO2 nano powder (30 nm) in aluminium metal matrix (AA2024), the material removal rate of developed metal matrix nanocomposite (MMNC) decreases whereas TWR and SR increase as compared to the base metal AA2024.

Micro-texture design criteria for cemented carbide ball-end milling cutters

Given the serious work hardening phenomenon, high chemical activity, severe tool wear, and poor workpiece surface quality during the cutting of titanium alloys, placing micro-texture on the tool surface decreases the tool-chip contact area and friction and plays the role of wear resistance and friction reduction. In order to improve the cutting performance of cutting tools, the present study examins the effect of micro-texture parameters of a cemented carbide ball-end milling cutter on cutting force, tool wear, and workpiece surface roughness and establishes a regression analysis model via regression analysis. We consider the cutting performance of a cemented carbide micro-texture ball-end milling cutter as an evaluation standard. A genetic algorithm is applied to the multi-objective optimization of micro-texture parameters, and a regression analysis model of micro-texture design criteria is established. This provides a standardised reference to select standard micro-texture parameters in the design and preparation of a cemented carbide micro-texture ball-end milling cutter.

A Role of cryogenic in Wire cut EDM process

Novel techniques are being focused on the enrichment of the performance characteristics under different machining processes. Cryogenic is one of such novel practices that tunes the surface integrity with vast variations with the traditional machining processes. Dimensional accuracy, surface roughness, material removal rate with less reduction in scrap of material is one of the prior targets of production process. Wire cut Electro Discharge Machining (WEDM) is one method that satisfy with upgrading performance characteristics. In order to step-up these performance characteristics in attaining superior quality, cryogenics practices have collaborated with the WEDM process. Present paper deals with the reviews of the researchers that have been performed over cryogenic treated WEDM process. Effect of performance characteristics like pulse on, pulse off, current, voltage, wire tension, wire feed is discussed with relation to material removal rate, tool wear rate and surface roughness evolved. Key concept of paper is to include the research ideology with best feasible techniques that can prevail in production practice in order of contribute to the forthcoming researches in industrial and production departments.

Surface modification of aluminium and its parametric optimization using grey relational analysis

This paper describes about the surface modification of aluminium workpiece using tungsten- copper (W-C) powder metallurgical (PM) green compact tool in electro discharge machining (EDM) process. Total nine experiments were conducted based on Taguchi L9 orthogonal array. The major response parameters selected were material transfer rate (MTR), tool wear rate (TWR) and surface roughness (Ra). The corresponding machining parameters were compaction load, peak current and pulse on-time. The experimental results were treated with grey relational analysis (GRA) for multi objective optimization. The highest grey relational grade (Gi) value was found to be 0.79 at the optimal parameter setting of 5 ton of compact load, 4 A of current and 400 µs of pulse on-time. ANOVA for grey relational grade was performed to investigate the effect of relevant process parameters in multi response criteria. The pulse on-time was found to be most influencing parameter having 49.77% of contribution followed by peak current and compact load of percentage 24.95% and 16.27% respectively.

Machinability assessment of titanium grade 2 alloy using deionized water in EDM

This paper aims to investigate the effect of input process parameters on the output parameters during electrical discharge machining (EDM) of titanium grade 2 alloy. The electrode material and the dielectric fluid used in this experimental study are copper and deionized water respectively. Effect of current and pulse-on time on material removal rate, tool wear rate and surface roughness have been studied. Various types of toxic gases are evolved due to the use of conventional hydrocarbon oil in EDM. To reduce these toxic emissions and make the process sustainable, deionized water is used as an alternative of hydrocarbon oil. The trend of variation of the response measures is investigated with the changes occurred in the input variables. MRR and TWR increase with increase in current. Whereas, MRR increases and TWR decreases with increase in pulse-on time. Surface roughness increases with increase in current and pulse-on time. Micrographs are studied to understand the surface texture of the workpiece. ANOVA is performed to know the percentage contribution of the variable parameters on the output performance measures.

Effect of material and machining features in electric discharge machining of 6061Al/rock dust composites

The current research investigates the effect of electric discharge machining (EDM) and material parameters on material removal rate (MRR), tool wear rate (TWR) and surface roughness (Ra) while machining the novel aluminium rock dust composite. Experiments have been performed in Vidyunt EM 150 EDM machine by considering parameters namely discharge current, pulse ON time, pulse OFF time, reinforcement size and level. The composites have been prepared through stir casting method by reinforcing various sizes (10, 20 & 30 μm) of rock dust particles with aluminium 6061 and at different levels (5, 10 & 15%). Since the number of input parameter is more, Taguchi’s design of experiments has been used to reduce the number of trials and grey relational analysis (GRA) technique has been used for optimization. Analysis of variance has been performed to identify the significance of the parameters and it has been found that all the considered parameters have significant effect on response variables. But in the case of multi performance characteristics analysis, only pulse ON time and pulse OFF time have the significance over GRG. Pulse ON time has the highest influence (55.36 %) on the GRG followed by pulse OFF time with 17.6% and rock dust weight % with 7.8%. From the confirmation experiments, it could be well said that the developed regression equations predicts the response parameters with minimal error and the grey relational grade has been improved significantly.

Selection of machining condition on surface integrity of additive and conventional Inconel 718

Abstract Inconel 718 is a nickel-based superalloy used in steam turbines, jet engines, etc., where it is subjected to high thermomechanical loads. Inconel 718 is the most preferred alloy in the above applications due to its excellent resistance to fatigue and creep. Inconel 718 is mainly strengthened by the precipitates which were formed during the heat treatment process by the combination of elements like Nb, Ti, and Al along with the base element Ni. Selective Laser Melting (SLM) is one of the most used additive manufacturing processes to manufacture components with high dimensional accuracy in a flexible manner with less material usage. The samples fabricated by SLM were subjected to two heat treatments: Hot Isostatic Pressing (HIP) to improve the density followed by the Aeronautic Heat Treatment (AHT) in order to improve the material properties. The heat-treated SLM samples have the same mechanical properties of the conventional Inconel 718 fabricated by the Cast and Wrought (C&W). The Central Composite face-centered Design (CCD) was used for the Design of Experiments (DOE) in which three different cutting speeds (vc) and feed rates (fz) were considered whereas the depth of cut (ap) is kept constant. Machining experiments were conducted under dry, Minimum Quantity Lubrication (MQL) and emulsion (Wet) conditions on both the cast and wrought (C&W) Inconel 718 and additive fabricated SLM Inconel 718. The optimum cutting condition for C&W and SLM Inconel 718 samples was determined based on three criteria: minimum specific cutting energy (Wc), minimum tool wear (Vb) and minimum surface roughness (Ra). From the overall results, it is being inferred that the SLM Inconel 718 produced better results compared to C&W Inconel 718.

Improving productivity with eco-friendly dielectrics in sustainable EDM machining of AISI 2507 super duplex stainless steel

Electric discharge machining (EDM) is renowned for machining intricate geometries of hard materials. The dielectric fluid is reflected to be the key indicator of sustainability. Conventional hydrocarbon dielectrics are considered to be toxic and emitting harmful aerosol emissions leading to environmental pollution. The bio-based dielectric has comparable features to conventional dielectric and thus can be replaced. The present analysis is projecting the new green dielectric fluids, named pongamia green dielectric (GD1) and neem green dielectric (GD2) for sustainable EDM of 2507 super duplex stainless steel. Material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR) are measured by varying pulse-on time (Ton), pulse-off time (Toff), peak current (Ip), voltage (v) and inter-electrode gap (IEG) in Taguchi's L27 experiments. GD1 and GD2 have outperformed conventional dielectric by 18.45% and 42.08% in terms of MRR, 5.9%, and 7.5% in terms of SR.

Optimization of Electrical Discharge Machining Process parameters for 17-7 PH Stainless Steel by using Taguchi Technique

In a number of industries, hard and fragile materials find a variety of applications. With the improvement and developments in innovative technologies, low weight- high strength, high resistance to temperature. Materials have been preparing to meet the industry requirements. The HSTR materials are difficult to machine in a conventional machining process in such cases either the tool may undergo extreme wear /damage or the work material will be damaged. To overcome the above problems there is a need for non-traditional machining process. In unconventional machining process, Electrical Discharge Machining process plays a vital role in metal cutting applications with highly accurate and excellent machining capabilities. Electric Discharge Machining (EDM) is a well-established un-traditional machining process in industries all over the world. Any electrically conductive materials can be easily machined. The foremost aim of this effort is optimization of process parameters of Electrical Discharge Machining for 17-7 PH steel by using Taguchi technique. The workpiece material was 17-7 PH (Precipitation Hardened) stainless steel and copper as an electrode. The process parameters of machining parameters, i.e., current, pulse on time, discharge voltage and Inter-Electrode Gap (IEG) on the outputs of Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (Ra), Overcut and Clearance in Electrical Discharge Machining are examined. The L9 orthogonal array was used to design the experimental layout for this work with MINITAB software.