Applied Mechanics and Materials Vols. 813-814

Abstract: In this investigation, the optimization of the multiple responses of Vickers hardness, Impact strength with notched and Un-notched conditions of the process parameters of rotational speed, tool tilt angle and feed rate with the straight cam profiled tool is considered. The three factors, five level rotatable central composite design are selected to optimize the responses of friction stir welded AA 8011 aluminium alloys. The highest relative efficiency is found using the data envelopment analysis to predict the optimum parameters. It reveals that at the rotational speed of 680 RPM, the tool tilt angle of 85 degrees and the feed rate of 24 mm/min the good weld quality can be achieved.

Abstract: In this paper, multi objective optimization of Gas Metal Arc Welding GMAW) parameters are carried out to yield good mechanical strength in welded joints. Most of the failures are occurred on the welded elements due to the setting of improper welding parameters. The strength of welded joints in GMAW depends on several input process parameters such as welding current, welding voltage, gas flow rate, torch angle, welding speed, wire size and electrode feed rate. Wrong selection of these process parameters will lead to bad quality welds. So there is a need to control the process parameters to obtain good quality welded joints. For getting the better values of these parameters, it needs to conduct experiments by varying the input process parameters that are affecting the strength of the welded joints. In this work nine experimental runs based on an L9 orthogonal array of Taguchi method are performed to optimize the strength of the welded joint. To achieve this Grey Relational Analysis (GRA) is used. In this work Aluminum6063 material is used as base material.

Abstract: Friction stir welding (FSW) has become a potential solid state joining technique with considerable advantages over conventional joining process. Defect-free friction stir welded joints with high joint strength are obtained when optimum process parameters are used. Although a large number of parameters govern the FSW process, the tool rotation speed, Welding speed and tool geometry are key parameters that influence the joint strength. In this work, a statistical model relating process parameters and the tensile strength (TS) of friction stir welded AA1100 joints is build using response surface methodology. The four independent variables are tool rotational speed (TRS), welding speed (WS), shoulder diameter (SD) and pin diameter (PD). Central Composite design is used and Analysis of Variance at 95% confidence level was applied to assess the adequacy of the developed model. Genetic algorithm is used for optimizing the parameters. The optimum process parameter values predicted using the genetic algorithm are as follows. Tool rotation speed: 1001.9 rpm; welding speed: 62 mm/min; shoulder diameter: 17.8 mm and pin diameter: 6.5 mm. The corresponding tensile strength of the joints is 73.1556 MPa

Abstract: This work is focused on the development of empirical model to predict the mechanical properties of welded Al-SiC metal matrix composites. Autogenous pulsed current-Tungsten inert gas (PC-TIG) welding was performed on 5mm thick Al-8%SiC composite plates. Regression equations were developed to predict the tensile strength, yield strength, percentage of elongation and bend strength of pulsed current TIG weld Al-SiC composite by varying weld parameters such as peak current, base current, pulse on time and pulse frequency. The effect of each pulsed current TIG welding parameters and interaction between two more parameters on the ultimate tensile strength, yield strength, percentage of elongation and bend strength were studied for clear understanding of PCTIG welding parameters. Improved mechanical properties viz. 136 MPa tensile strength, 117 MPa yield strength with 15% elongation were achieved using optimal PCTIG welding parameters. The predicted values were experimentally verified for consistency and validation. This study also resulted in understanding the significant factors which were responsible for improved weld strength of the chosen candidate material.

Abstract: In recent scenario, the automation in weld cladding process has a challenging task for most of the industries like automotive, petrochemical and food processing industries. Because to achieve the best quality of the weld clad bead geometry during automated process it is important to have complete control over the selected process parameters. The cladding process enhances the base material properties. Therefore, it is essential to predict the relationship between the process parameters and response the second order polynomial regression equation has to be developed. It makes more effectiveness of automated weld cladding processes. Palani and Murugan [1] developed a mathematical model for a flux cored arc welding process using an RSM method to study the direct effects and interaction effects of process parameters on clad bead geometry.

Abstract: AZ31B Magnesium alloy plates were successfully joined by using alternating current pulsed Metal inert gas welding (AC p-MIGW) with AZ61 Magnesium alloy wire as the filler metal. The macrostructure, tensile strength, micro hardness and corrosion rate of welded magnesium alloy joints were studied. Results showed that magnesium alloy plates could be successfully joined by pulsed MIG welding under specified process parameters. The average tensile strength of the joint was 81.34 N/mm2. The micro hardness was averagely about 67.62 HV. The joint was brittle fractured in the middle of weld zone. The corrosion rate of the welded joint was found to be 0.0112 mm/year.

Abstract: Welding is basic part of the most modern assembly and manufacturing operations. Shielded metal Arc Welding process has hard facing and fabrication job application due to low cost electrode, increasing alloy transfer efficiency and low dilution with substrate without losing production capacity. SMAW electrode is coated with metal mixture called flux, which on decompose produce gases to restrict weld contamination, generating deoxidizers to disinfect the weld. The choice of electrode for SMAW lies on a number of factors, like weld material, welding direction and the preferred weld properties. The present paper investigate the microstructure and hardness properties of the Low carbon steel pipe welded using shielded metal arc welding with different electrode combinations.

Abstract: Metal matrix composites (MMCs) have proved their viability as good alternatives to conventional alloys in high strength and stiffness application in industries like automobile, aerospace and mineral processing. Al metal matrix composites (MMCs) are being considered as a group of advanced materials for their lightweight, low coefficient of thermal expansion, and good wear resistance properties. The optimization of parameter has been done by using different techniques like Taguchi, DOE and their results were verified by ANOVA. Signal-to-noise ratio and Analysis of variance (ANOVA) were used to investigate the influence of parameters on the wear rate. Based on various papers the conclusion of this review paper is to study the influence of applied load, sliding speed and sliding distance on the various parameter such as optimum wear and co-efficient of friction of Al alloy-B₄C composite to enhance the quality of product and suggest the best combination of wear parameter which helps to reduce the wear of product with the help of Taguchi method. The wear resistance of the composite was found to be considerably higher than that of the matrix alloy and increased with increasing particle content. The major observation based on reviewed papers is that the major factor in determining the wear rate is load applied followed by distance and sliding velocity whereas distance affects the coefficient of friction to a large extent followed by load and sliding velocity.

Abstract: This paper proposes the prediction of cutting temperature, tool wear and metal removal rate using fuzzy and regression modeling techniques for the hard milling process. The feed per tooth, radial depth of cut, axial depth of cut and cutting speed were used as process state variables.The experiements were conducted using RSM based central composite rotatable design methodology. Regression and fuzzy modeling were used to evaluate the input – output relationship in the process. It is interesting to observe that the R² and average error values for each response are very consistent with small variations were obtained.Also, the confirmation results show that very less relative error varitions. Thus, the developed fuzzy models directly integrated in manufacturing systems to reduce the more computational complexity in the process planning activities.

Abstract: Carbon fibre reinforced plastic (CFRP) composite materials has unique mechanical and functional properties due to the combination of its constituent materials that possesses desirable properties. The present paper focuses on analysis of surface roughness in drilling of fly ash filled carbon fibre reinforced composites produced through compression moulding route. Experiments are conducted on a radial drilling machine using Taguchi’s experimental design. Drilling test is carried out using coated HSS drill of 6 and 10 mm diameter. The effect of drill diameter, wt % of fly ash, spindle speed and the feed rate are investigated on surface roughness. The relative significance of the various parameters has been found using ANOVA.