AISI D2 Research Articles

Parametric Optimization of Trochoidal Step on Surface Roughness and Dish Angle in End Milling of AISID3 Steel Using Precise Measurements.

Tool steel play a vital role in modern manufacturing industries due to its excellent properties. AISI D3 is a cold work tool steel which possess high strength, more hardenability and good wear resistance properties. It has a wide variety of applications in automobile and tool and die making industries such as blanking and forming tools, high stressed cutting, deep drawing and press tools. The novel ways of machining these steels and finding out the optimum process parameters to yield good output is of practical importance in the field of research. This research work explores an attempt to identify the optimized process parameter combinations in end milling of AISI D3 steel to yield low surface roughness and maximum dish angle using trochoidal milling tool path, which is considered as a novelty in this study. 20 experimental trials based on face centered central composite design (CCD) of response surface methodology (RSM) were executed by varying the input process factors such as cutting speed, feed rate and trochoidal step. Analysis of variance (ANOVA) was adopted to study the significance of selected process parameters and its relative interactions on the performance measures. Desirability-based multiple objective optimization was performed and the mathematical models were developed for prediction purposes. The developed mathematical model was statistically significant with optimum conditions of cutting speed of 41m/min, feed rate of 120 mm/min and trochoidal step of 0.9 mm. It was also found that the deviation between the experimental and predicted values is 6.10% for surface roughness and 1.33% for dish angle, respectively.

Mechanisms of die wear and wear-induced damage at the trimmed edge of high strength steel sheets

Die wear during trimming of advanced high strength steel (AHSS) sheets deteriorates the edge quality of trimmed sheets. In this work, the mechanisms of AISI D2 steel trim die wear and their effects on plastic deformation and fracture behaviour of the sheared edge of DP980 steel sheet were examined. A mechanical press equipped with D2 inserts was used to trim DP980 sheets with a clearance of 0.14 mm (10%). Abrasion and microchipping were identified as the wear mechanisms operating at the upper die, with microchipping becoming more dominant after 60,000 trimming cycles. The burr height and the length of the burnish zone of sheared DP980 sheets increased linearly with the chipped die edge percentage. The shear strains in the shear effected zone (SAZ) were estimated using martensite displacements as metallographic markers in the ferrite matrix as a function of the depth beneath the sheared edge. The depth of SAZ, and the plastic strains at a given depth within the SAZ increased with the number of trimming cycles. Correlation of the local stress and strain values generated in the SAZ showed that a saturation flow stress was reached near the sheared edge. The damage in SAZ occurred in the form of crack formation at the martensite/ferrite interfaces and fracture of martensite. Die wear reduced the tensile ductility of the DP980 sheets, and the fracture mode in tension changed from ductile with localized neck to more brittle sheared edge fracture initiating from surface cracks after 60,000 cycles.

Evaluation of tool life and workpiece surface roughness in turning of AISI D6 hardened steel using PCBN tools and minimum quantity of lubricant (MQL) applied at different directions

The main objective of this work is to evaluate the tool life and the workpiece surface roughness when applying a vegetable-based cutting fluid by minimum quantity of lubricant (MQL) at three different directions (main tool flank face, secondary tool flank face, and overhead) in turning AISI D6 hardened steel with polycrystalline cubic boron nitride (PCBN) tools with Al2O3 ceramic binder and TiN coating. Dry cutting was also tested for comparisons. Tool wear analyses were performed on the tools at the end of their lives within a scanning electron microscope (SEM). The application of the cutting fluid by MQL technique in the direction between the main tool flank face and the workpiece showed better results than the dry condition. The application of MQL through other directions (overhead and between the secondary tool flank face and the workpiece) also showed competitive results. Abrasion and adhesion were the prevailing mechanisms for the wear of the tools.

Wear and Corrosion Resistance of Chromium–Vanadium Carbide Coatings Produced via Thermo-Reactive Deposition

Chromium carbide, vanadium carbide, and chromium–vanadium mixture coatings were deposited on AISI D2 steel via the thermo-reactive deposition/diffusion (TRD) technique. The carbides were obtained from a salt bath composed of molten borax, ferro-chrome, ferro-vanadium, and aluminum at 1020 °C for 4 h. Analysis of the morphology and microstructure of the coatings was done via scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The hardness of the coatings was evaluated using nano-indentation, and the friction coefficient was determined via pin-on-disk (POD) testing. The electrochemical behavior was studied through potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS). The XRD results show evidence of the presence of V8C7 in the vanadium carbide coating and Cr23C6 and Cr7C3 in the chromium carbide coating. The hardness value for the vanadium–chromium carbide coating was 23 GPa, which was higher than the 6.70 ± 0.28 GPa for the uncoated steel. The wear and corrosion resistance obtained was higher for the niobium–chromium carbide coating, due to the nature of the ceramic carbide produced.

Performance of Near Dry Hard Machining Through Pressurised Air Water Mixture Spray Impingement Cooling Environment

The present paper emphasizes on experimental investigation, mathematical modelling, optimisation, tool life and cost analysis during machining of AISI D2 (heat treated) (55±1 HRC) steel using uncoated carbide tool through a novel method under spray impingement cooling environment. Taguchi based L16 orthogonal array was utilised to conduct the experiments. Analysis of variance with 95% confidence level shows that the feed and depth of cut, are the most compelling factor towards surface roughness as well as chip reduction coefficient whereas cutting speed is the utmost compelling feature associated to flank wear as well as chip-tool interface temperature. Optimised result is identified as v1-f1-d1 (machining speed of 63 m/min; cutting feed of 0.04 mm/rev and depth of cut of 0.1 mm) based on grey relational analysis and tool life is found to be 15 minutes at optimised cutting conditions. Flank wear due to abrasion, catastrophic failure due to diffusion, chipping and notch wear are noticed as the major tool wear mechanisms in hard turning. Mathematical machinability models show statistically significance because due to the superior coefficient of correlations. As the global machining cost for each part is less, uncoated carbide tools can machine effectively, efficiently and economically at optimum cutting conditions under spray environment.

Properties and tribological performance of ceramic-base chromium and vanadium carbide composite coatings

In the current study, the surface of AISI D2 steel was coated with the powder blends of ferro-vanadium (Fe-V) and ferro-chromium (Fe-Cr). The coatings were performed using a thermo-reactive diffusion (TRD) treatment by the pack cementation method at three different temperatures (900 °C, 1000 °C, and 1100 °C) and three different durations (1 h, 2 h, and 3 h). The structural and mechanical characteristics of the coatings were compared between the treatment groups. For this aim, the types of the formed phases, the microstructure, the microhardness, the surface roughness, and the wear and friction performance of the coated samples were examined. XRD analysis found composite carbide coatings including chromium carbide (Cr-C), vanadium carbide (V-C), and chromium vanadium carbide (Cr-V-C). The coatings' thickness was 11.3–23.2 μm, hardness was 2100–2500 HV, and average surface roughness (Ra) was 0.286–0.550 μm, depending on the treatment condition. The vanadium containing phase contents of the coatings increased with the elevating coating temperatures. The formed composite coating layers caused a change in the appearance of wear track and wear mechanism on the material surface. After the coating process, there found to be a decrease in the friction coefficient as well as an improvement in the wear resistance up to 7 times. In the composite coating layers, the increase in V-C content in comparison to Cr-C led to an enhancement in wear resistance on the material surface.

Multi‐response optimization of the machining characteristics in electrical discharge machining (EDM) using span‐20 surfactant and chromium (Cr) powder mixed

AbstractEffects of Chromium (Cr) powder concentrations (Cp) and Span‐20 surfactant concentrations (Cs) on AISI D2 hardened steel were evaluated using response surface methodology (RSM) and parameter processing parameter were optimized for optimal parameter conditions using multi‐response desirability function. Responses taken involved material removal rate (MRR), electrode wear rate (EWR) and surface roughness (Ra). The experimental plan was based on the face centered, central composite design (CCD) using version 10.0 of the Design Expert software. The results identified that Cp is the most important parameter to maximize material removal rate (MRR) and minimize electrode wear rate (EWR) and surface roughness (Ra). With the topmost desirability solution, the suggested optimum parameter condition of Cp and Cs were 2.155 g/L and 10.000 g/L, respectively.

Wear Behavior of Borided AISI D2 Steel under Linear Reciprocating Sliding Conditions

AISI D2 steel is the most commonly used cold-work tool steel in its grade. In this study, micro-structural characterization and some mechanical properties of borided AISI D2 steel samples were investigated. The boriding treatment was carried out at 900 and 1000°C for 3, 5 and 7 hours by using Ekabor 2 powder and a solid-state box boriding technique. Wear behavior of borided and non-borided steel were conducted by linear reciprocating wear test using an Al2O3 ball as the counterpart. The sliding distances and the sliding speed were remained constant at 250 m and 5 mm/s, respectively, with the loads of 10, 20 and 30 N (being applied). Microstructural characterization revealed homogeneous, dense and fine-grained structure which had predominant dual phase boride (FeB+Fe2B) layer with minor of Cr-B, Mo-B, V-B, Mn-B interstitial compounds being present as well. The thickness and hardness values of the boride layer were in the range of 46.23–126.8 µm and 2005–2227 HV0.1, respectively, depending on the process conditions. The results showed that the wear resistance improved by up to 6.7 times in comparison with non-borided AISI D2 steel. Severe plastic deformation was the effective wear mechanism in non-borided AISI D2 steel. However for the samples which were borided at 900 and 1000°C, delamination and polishing type of wear mechanisms were observed, respectively. Surface hardness and boride layer thickness had a great effect both on wear rate and wear mechanism.

Process Parameters Optimization Using Taguchi’s Orthogonal Array and Grey Relational Analysis during Hard Turning of AISI D2 Steel in Forced Air-Cooled Condition

Optimization of process parameters play an important role in machining operations. The present work deals with a multi-objective optimization method (Grey relational analysis) and Taguchi’s orthogonal array (OA) technique in machining of AISI D2 steel using coated carbide tool in forced air-cooled condition considering it to be environment friendly. The process parameters considered are cutting speed, feed and depth of cut having three levels each. The performance parameters are surface roughness, flank wear and cutting force. Taguchi’s orthogonal array L9 is considered for the experimental design. Grey relational analysis technique is used for finding the optimal settings of the process parameters to obtain the value of surface roughness, flank wear and cutting force. The optimum grey relational grade has been found out to get the optimal setting of the experimental run. Then level wise grey relational grade has been found out from the experimental run for each parameter. The optimal settings based on the rank of the grey relational grade in the experimental run and level wise optimal settings of the parameters from the grey relational grade have been compared. The improvement of performance parameters is confirmed from the grey relational prediction analysis in comparison to optimal values in the experimental run.

Determining The Effect of Machining Parameters on Material Removal Rate of AISI D2 Tool Steel in Electrochemical Machining Process Using The Taguchi Method

Electrochemical machining is non-traditional machining which is commonly used to manufacture hard materials and to produce complicated shapes of irregular sizes in the product. In this paper, an experimental study is given for drilling AISI D2 tool steel. The focus of this study is to optimize machining parameters based on the Taguchi L9 orthogonal array approach to maximize material removal rate (MRR). Voltage, a concentration of the electrolyte, and gap width were selected as machining parameters of ECM (electrochemical machining) process. The signal to noise ratio (SN) and the analysis of variance (ANOVA) are statistical methods used to investigate the effects of machining parameters. As the results, the maximum MRR is 0.153 g/min obtained at voltage 48 V, electrolyte concentration at 150 g/l, and gap width at 1 mm. electrolyte concentration is the machining parameters that most influence the response.

Investigation of Most Influencing Parameter for Surface Roughness and MRR in AISI D3 Steel Alloy by using Taghuci Approach

Investigation of Most Influencing Parameter for Surface Roughness and MRR in AISI D3 Steel Alloy by using Taghuci Approach

Analysis and modeling of surface roughness based on cutting parameters and tool nose radius in turning of AISI D2 steel using CBN tool

Surface roughness of components having hardness above 45 HRC (Rockwell hardness) like bearings, dies, tools etc. draws specific attention during the turning process. Analysis of surface roughness is presented by many researchers based on cutting conditions during hard turning. In this paper, analysis of surface roughness of AISI D2 steel in hard turning with CBN (cubic boron nitride) tools is performed based on variables like cutting speed, feed and nose radius at a constant depth of cut. Variation of feed affects surface roughness most significantly followed by cutting speed and tool nose radius. Prediction of surface roughness considering simultaneous effect of cutting parameters and tool geometry is very difficult. Here, a mathematical model is developed based on simultaneous effect of feed, cutting speed and nose radius. Moreover, developed model is validated using different sets of cutting conditions and found in close agreement with experimental results.

Structural and tribological characterization of amorphous and crystalline titanium-nickel coatings

The interest in titanium-nickel (TiNi) alloys has increased with the discovery of the versatile properties of these alloys. In this study, the structural, mechanical and tribological properties of amorphous and crystalline TiNi coatings were investigated. The TiNi coatings were deposited with magnetron sputtering system. The crystallization process was conducted in a vacuum heat treatment furnace. The structural properties of the coatings were investigated with XRD, SEM and EDS analyses. Micro-hardness and pin-on-disc wear tests were used to obtain the mechanical and tribological properties of the coatings. AISI D2 steel, AISI 52100 steel, Aluminum 2024 alloy and copper were used as substrate materials, hence the effects of different substrates were also investigated. The highest coating hardness was obtained as 8.5 GPa and the lowest coefficient of friction value was obtained as 0.18. The tribological tests showed that the amorphous and crystalline TiNi coatings have different coefficient of friction and wear rate and using different substrate affects these properties.

Investigation of the Cutting Performance of Cutting Tools Coated With the Thermo-Reactive Diffusion (TRD) Technique

The life of cutting tools used in metal cutting operations is limited due to wear. Therefore, increasing wear resistance is of great importance for minimizing economic losses. By using different coating techniques, tools may be coated with harder compounds for enhancing wear resistance. Tool hardness and toughness are also increased through coating. In this study, boron and titanium coatings were applied on round cutting tool surfaces made of AISI D2 and AISI M2 steels by the thermo-reactive diffusion technique. AISI D2 cutting tool surface was coated with boron at 950 °C for 1 hour, and AISI M2 cutting tool surface was coated with boron at 1000 °C for 1 hour. After boron coating, the surfaces of the samples were coated with titanium at 1050 °C for 1 hour. The coated samples were characterized by using SEM, X-ray diffraction, EDS analysis, and micro hardness tests. Machining tests were performed to observe the wear resistance of the samples and the roughness of the machined surface. Machining tests were carried out on DIN 1651 free-cutting steel. Cylindrical turning tests were run at three different cutting speeds, 38, 73, and 138 m/min. and at three different feeding values, 0.08, 0.12, and 0.16 mm/rev. The results showed that the boron- and titanium-coated tools performed 50% better than the just boron-coated tools. In terms of surface roughness, it was determined that there was no significant difference between the coated and uncoated tools. The cutting performance values of our coating method were compared to those of ISCAR brand RCMT (code of the insert used in turning and milling operations in the ISO norm) inserts coated with the PVD and CVD methods, and it was seen in the experimental results that the tool coated with the TRD method performed better.

Analysis of the Dynamic Stability of Ball-End Milling of AISI D6 Hardened Steel

AISI D6 hardened steel is a difficult to cut material that it is employed in mould and die manufacturing where long ball-end mills are frequently required to machine deep cavities. This condition can lead to excessive vibration between tool and workpiece resulting in a poor surface finishing and reduced tool life. This work analyses the dynamic stability of ball-end milling of AISI D6 hardened steel for different tool path orientations at inclined workpiece angles of 15o and 75o. The evaluation of stability is based on the surface texture and spectrum analysis of the vibration signals. The results showed that for workpiece inclination angle of 15o chatter occurred in vertical upward down-milling and vertical downward up-milling. Best surface texture with tool marks consistent with pick feed and feed directions were generated by applying horizontal downward tool paths that produced the least vibration. Only forced vibrations occurred for the workpiece inclination angle of 75o. The highest peaks of the spectra corresponded to the harmonics of the tooth passing frequency closer to the natural frequency of the system. High magnitudes in the spectrum were found for vertical upward down-milling that generated a less uniform surface texture.

Prediction of Machining Performances in Hardened AISI D2 Steel

Abstract The current research focuses on predicting the surface roughness, the flank wear and (chip–tool) interface temperature when turning the hardened AISI D2 (55 ± 1 HRC) employing a mixed ceramic (Al2O3 + TiCN) tool in dry condition. Quadratic regression methodology has been introduced and their performances are compared on basis of mean error percentage among experimental and expected data. Normal probability plots are developed to understand the distribution of result data. ANOVA is implemented for all responses showing significant established regression models at 95 % of the level of confidence. 3D surface graph indicates that the feed is the most dominant term for Ra while cutting speed was more dominant for T and VBc.

Experimental Investigation and Surface Roughness analysis on Hard Turning of AISI D2 Steel using Polycrystalline Cubic Boron Nitride (PCBN)

Abstract The performance of polycrystalline cubic boron nitride (PCBN) was studied to investigate surface roughness analysis at various machining parameters. The PCBN tools were used in tool steel AISI D2 steel with hardness of 64 HRC. Machining test was performed with dry cutting condition at different cutting speed, feed and depth of cut. In order to obtain desired surface quality by machining, proper machining parameter selection is very essential. This can be achieved by higher quality and productivity in metal cutting industry. The aim of the present work is to investigate effect of process parameter on surface finish and material removal rate (MRR) to obtain the optimal setting of the process parameters. It influences the cutting parameters during machining L27 experimental will run based on an orthogonal array method. During the experimental process parameters such as speed, feed and depth of cut are used to explore their effect on the surface roughness (Ra) of the work piece. Chip morphology study indicates different types of chips operating under different cutting conditions.

A comparative study in prediction of surface roughness and flank wear using artificial neural network and response surface methodology method during hard turning in dry and forced air-cooling condition

In the present work, a turning operation is performed in a green environment of dry and forced air-cooled condition to avoid the flooded coolant or minimum quantity lubrication. The work piece material considered is hardened AISI D2 steel (48 HRC) and the tool material is tungsten coated carbide tool. Cutting speed (v), feed rate (f) and depth of cut are taken as process parameters and surface roughness, flank wear, cutting force and feed force as performance parameters. Dry turning (DT) is found to be favourable for minimising surface roughness, cutting force and feed force, while air-cooled turning (ACT) is favourable for reducing flank wear. Artificial neural network (ANN) and response surface methodology (RSM) models have been developed for prediction of surface roughness and flank wear. Regression coefficient (R2), confirmed that ANN model is better as compared to that of RSM model.

A comparative study in prediction of surface roughness and flank wear using artificial neural network and response surface methodology method during hard turning in dry and forced air-cooling condition

In the present work, a turning operation is performed in a green environment of dry and forced air-cooled condition to avoid the flooded coolant or minimum quantity lubrication. The work piece material considered is hardened AISI D2 steel (48 HRC) and the tool material is tungsten coated carbide tool. Cutting speed (v), feed rate (f) and depth of cut are taken as process parameters and surface roughness, flank wear, cutting force and feed force as performance parameters. Dry turning (DT) is found to be favourable for minimising surface roughness, cutting force and feed force, while air-cooled turning (ACT) is favourable for reducing flank wear. Artificial neural network (ANN) and response surface methodology (RSM) models have been developed for prediction of surface roughness and flank wear. Regression coefficient (R2), confirmed that ANN model is better as compared to that of RSM model.

Weldability and Joining Characteristics of AISI D2/AISI 304 Steels Using Semisolid Diffusion Joining

The application of hybrid structures or components made of dissimilar metal offers the potential to utilize the advantages of different materials often providing unique solutions to engineering requirements. However, the joining of materials by conventional welding techniques becomes difficult if the physical properties such as melting temperature and thermal expansion coefficients of the two materials are different. In this study, a new process of joining semi-solid AISI D2 tool steel and AISI 304 stainless steel using a partial remelting method is proposed. Moreover, the effect of the holding time on the microstructural evolution was investigated. The processing temperatures for the thixojoining was 1320°C and held for 5, 12, 20 and 30 minutes, respectively. The results obtained from investigating the basic geometries demonstrated a good joining quality that differs from the conventional process of welding. Metallographic analyses along the joint interface between semi-solid AISI D2 and 304 stainless steel showed a smooth transition from one to the other, with neither oxides nor microcracking being observed.