Effect of parameters such as current density, welding time, electrodes force and holding time after welding on tensile-shear strength of dissimilar joint were analyzed. Taguchi method was used to ...design the experiments and Minitab software was used to analyze the effect of parameters and obtain an optimum condition. The microstructure of the optimum condition was analyzed by Scanning Electron Microscope (SEM). The strength of the join was analyzed by tensile-shear test. Fracture mode was assessed by optical microscope. Results showed that current density, holding time after welding, welding time and electrodes force were the most effective parameters hierarchically. Optimum current density of 8 Kamp, holding time after welding of 40 cycle, 16 cycle welding time and 5 kN electrode force were defined as the optimum parameters to join the sheets. Weld nugget (WN) had a martensitic structure containing a relatively high strength and hardness. Its fracture mode was pullout failure.
•Spot welding on DP600 steel and AISI 304 stainless steel sheet were performed.•Optimum conditions was obtained for four weld parameters.•Taguchi method was used to obtain the level of four welding parameters.•Weld nugget Microstructure was martensitic with high mechanical strength & hardness.•The fracture mode of the joint was pullout failure.
The widespread application of AISI 304 austenitic stainless steel is mainly due to its high corrosion resistance. However, its field of application can be expanded by improving its tribological ...properties. This work deposited thin films on AISI 304 steel substrates through different plasma treatments using a titanium cathodic cage to evaluate which configuration best combines the films' mechanical, tribological, and corrosion resistance properties. The samples were analyzed by X-ray diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Vickers microhardness, Rockwell C adhesion, fixed-sphere micro-abrasion wear, and Electrochemical Impedance Spectroscopy. The simultaneous duplex treatment sample exhibited the best wear resistance results. It was the film with the lowest loss of corrosion resistance compared to the untreated substrate, highlighting the efficiency of this technique in obtaining surfaces with good mechanical, tribological, and corrosion properties obtained in treatment times shorter than conventional duplex treatment.
High strength, high ductility, low thermal conductivity and high work hardening effects of austenitic stainless steels are the foremost factors that make their machinability difficult. Machining, ...especially dry machining of such steels, has been one of the most significant challenges for carbide cutting tools. In this research study, TiAlN, AlTiN and TiAlSiN coatings were successfully employed through HiPIMS coating system on cutting tools for dry machining of AISI 304 stainless steel. As-deposited coatings were confirmed through FESEM and XRD analysis. The input process parameters including coating material have been considered for optimizing the multiple objectives such as surface roughness Ra, Rz, tool wear rate and material removal rate. Multi-criteria decision making involving grey fuzzy coupled Taguchi method was adopted to solve the optimization for multiple response characteristics. Analysis of variance was conducted to analyze the contribution percentage of each process parameter. From the results of MCDM-based GFCT, the optimized setting for best output responses was determined as coating: TiAlSiN, cutting speed: 180 m/min, feed rate: 0.1mm/rev and depth of cut: 1.5 mm. Feed rate had significantly contributed about 42.74% on the output measures, followed by coating, depth of cut and cutting speed. The responses were predicted with an accuracy of 96.5% through GFCT technique. Finally, a confirmatory experiment was carried out to support the accuracy of optimal process parameters.
The enormous use of cutting fluid in machining leads to an increase in machining costs, along with different health hazards. Cutting fluid can be used efficiently using the MQL (minimum quantity ...lubrication) method, which aids in improving the machining performance. This paper contains multiple responses, namely, force, surface roughness, and temperature, so there arises a need for a multicriteria optimization technique. Therefore, in this paper, multiobjective optimization based on ratio analysis (MOORA), VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR), and technique for order of preference by similarity to ideal solution (TOPSIS) are used to solve different multiobjective problems, and response surface methodology is also used for optimization and to validate the results obtained by multicriterion decision-making technique (MCDM) techniques. The design of the experiment is based on the Box–Behnken technique, which used four input parameters: feed rate, depth of cut, cutting speed, and nanofluid concentration, respectively. The experiments were performed on AISI 304 steel in turning with minimum quantity lubrication (MQL) and found that the use of hybrid nanofluid (Alumina–Graphene) reduces response parameters by approximately 13% in forces, 31% in surface roughness, and 14% in temperature, as compared to Alumina nanofluid. The response parameters are analyzed using analysis of variance (ANOVA), where the depth of cut and feed rate showed a major impact on response parameters. After using all three MCDM techniques, it was found that, at fixed weight factor with each MCDM technique, a similar process parameter was achieved (velocity of 90 m/min, feed of 0.08 mm/min, depth of cut of 0.6 mm, and nanoparticle concentration of 1.5%, respectively) for optimum response. The above stated multicriterion techniques employed in this work aid decision makers in selecting optimum parameters depending upon the desired targets. Thus, this work is a novel approach to studying the effectiveness of hybrid nanofluids in the machining of AISI 304 steel using MCDM techniques.
The main objective of this investigation is to study the effect of diffusion bonding time on microstructure and mechanical properties of dissimilar Ti6Al4V titanium alloy and AISI 304 austenitic ...stainless steel joints. The dissimilar joints of Ti6Al4V titanium alloy and AISI 304 steel were developed using the different levels of bonding time (30, 45, 60, 75 and 90 min) in a vacuum chamber at a bonding temperature of 900 °C and compressive pressure of 14 MPa. The microstructure of joints was analyzed using optical microscopy (OM) and scanning electron microscopy (SEM). The elemental analysis of joint interface was studied using the SEM energy dispersive spectroscopy (EDS). The evolution of intermetallic compounds at the joint interface was analyzed using X-ray diffraction (XRD). The ram tensile tests and lap shear tests were performed to assess the bonding strength and lap shear strength of dissimilar joints. Results showed that the dissimilar joints of Ti6Al4V alloy–AISI 304 steel developed using the diffusion bonding time of 75 min showed higher lap shear strength of 151 MPa and bonding strength of 244 MPa due to the better coalescence of the joining surfaces and evolution of optimum width of diffusion region having minimum embrittlement effects.
The Technique for order preference by similarity to ideal solution (TOPSIS) method of optimization is used to analyze the process parameters of the micro-Electrical discharge machining (micro-EDM) of ...an AISI 304 steel with multi-performance characteristics. The Taguchi method of experimental design L27 is performed to obtain the optimal parameters for inputs, including feed rate, current, pulse on time, and gap voltage. Several output responses, such as the material removal rate, electrode wear rate, overcut, taper angle, and circularity at entry and exit points, are analyzed for the optimal conditions. Among all the investigated parameters, feed rate exerts a greater influence on the hole quality. ANOVA is employed to identify the contribution of each experiment. The optimal level of parameter setting is maintained at a feed rate of 4 μm/s, a current of 10 A, a pulse on time of 10 μs, and a gap voltage of 10 V. Scanning electron microscope analysis is conducted to examine the hole quality. The experimental results indicate that the optimal level of the process parameter setting over the overall performance of the micro-EDM is improved through TOPSIS.
In the engineering sector, machining plays a significant role. The ability of the cutting zone to dissipate heat has grown in importance for the machining industry’s sustainability. Government ...legislation is pushing the industry to use fewer conventional lubricants as concerns about the effects on the environment and human health grow. This shifts attention to Minimum Quantity Lubrication (MQL) and biodegradable oils. The purpose of this study is to show how well two vegetable oils, in their raw forms, perform as cutting fluids during the MQL turning process of AISI 304 stainless steel. Each vegetable oil’s physiochemical and lubricating qualities were examined separately. After that, the two oils that comprised the hybrid vegetable oil were blended at a ratio of 0.5:0.5. During machining with an external threading tool, the hybrid vegetable oil was compared to its equivalent mineral-based oil in terms of cutting temperature and surface roughness. The Taguchi L9 orthogonal array was used in the study. According to the data, the cutting temperature was lowest when cutting with mineral oil, and highest when cutting with a hybrid mixture. In general, the mineral oil produced a reduced surface roughness compared to the vegetable oil mixture by about 68.6%. The combo of palm kernel and yellow orleander oil marginally outperformed mineral by about 2.3% when it came to cutting temperature. The significance of this study is to develop a more sustainable and environmentally friendly lubricants for industrial applications.
Surface roughness is considered as an important measuring parameter in the machining industry that aids in ensuring the quality of the finished product. In turning operations, the tool and workpiece ...contact develop friction and cause heat generation, which in turn affects the machined surface. The use of cutting fluid in the machining zone helps to minimize the heat generation. In this paper, minimum quantity lubrication is used in turning of AISI 304 steel for determining the surface roughness. The cutting fluid is enriched with alumina nanoparticles of two different average particle sizes of 30 and 40 nm. Among the input parameters chosen for investigation are cutting speed, depth of cut, feed rate, and nanoparticle concentration. The response surface approach is used in the design of the experiment (RSM). For the purpose of estimating the surface roughness and comparing the experimental value to the predicted values, three machine learning-based models, including linear regression (LR), random forest (RF), and support vector machine (SVM), are utilized in addition. For the purpose of evaluating the accuracy of the predicted values, the coefficient of determination (R2), mean absolute percentage error (MAPE), and mean square error (MSE) were all used. Random forest outperformed the other two models in both the particle sizes of 30 and 40 nm, with R-squared of 0.8176 and 0.7231, respectively. Thus, this study provides a novel approach in predicting the surface roughness by varying the particle size in the cutting fluid using machine learning, which can save time and wastage of material and energy.
Chemical polishing of metals with nanostructured media, such as water-in-oil (w/o) microemulsions, is of interest for improving the procedure of polishing metals with concentrated acids because the ...etchant (acid) concentration in the microemulsions can be much lower. It was shown that w/o microemulsions in the sodium dodecyl sulfate–1-butanol–kerosene–aqueous HCl system can be used for chemical polishing of 08Kh18N10 (AISI 304) stainless steel. Regions of existence of microemulsion in this system were determined, and conditions of chemical polishing of stainless steel with a sodium dodecyl sulfate microemulsion were chosen. Conditions of cleaning of the surface of a stainless-steel sample after chemical polishing were selected so that to ensure the most complete removal of microemulsion components from the steel surface without changing the surface microrelief.
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