K. Panneerselvam

Machinability study of hybrid-polymer composite pipe using response surface methodology and genetic algorithm

Polymer–matrix composites are very popular due to their low cost and simple fabrication methods. While techniques and methodologies for composites design are emerging, the knowledge and understanding of machining issues lag far behind. The objective of the work is to analyze the influence of machining parameters on the material characteristics of hybrid-composite pipes. Turning operation was carried out as per the design of experiments by central composite design in hybrid polymer composite pipe made of carbon fiber and Aramid fiber. Based on the experimental results, regression analysis was conducted to determine the input–output relationships of the process. A mathematical model is developed, and the responses are predicted. The effects of each process parameter on the response were analyzed using response surface methodology. The process parameters were then optimized using genetic algorithm to yield minimum cutting force and minimum surface roughness (Ra).

EXPERIMENTAL INVESTIGATION ON FRICTION STIR WELDING OF CRYOROLLED AA2219 ALUMINUM ALLOY JOINTS

In this paper, experimental investigation on cryorolled aluminum AA2219-T87 plate by using friction stir welding (FSW) process is carried out. AA2219-T87 plates with a size of 200×100×22.4 mm were rolled and reduced to 12.2mm thickness (more than 45% of reduction in total thickness of the base material) at cryogenic temperature (operating temperature range −90–−30∘C). The cryorolled (CR) plates have reduced grain size, improved hardness and increased corrosion resistance property compared with the uncryorolled AA2219-T87 plates. FSW joints of cryorolled AA2219-T87 plates were prepared using cylindrical threaded FSW tool pin profile. Mechanical and metallurgical behaviors of friction stir welded joints were analyzed and the effects of the FSW process parameters are discussed in this paper. The variation of microhardness in the FSW joint regions were correlated with the microstructure of FSW joints. Cryorolled plate and FSW joints were tested for corrosion resistance using potentiodynamic polarization test. FSW joints shows better result during the corrosion resistance analysis compared to base AA2219-T87. The X-ray diffraction (XRD) test results showed that fine α-Al grains with eutectic phase (Al2Cu) were present in the weld nugget (WN). The large clusters of strengthening precipitates were reduced in size and merged with the weld nugget portion.

Machining Parameter Optimization of Bidirectional CFRP Composite Pipe by Genetic Algorithm

Abstract Composite materials such as fiber-reinforced composites (FRP) are extensively used in todays industries such as aerospace, automotive, and shipping because of their high specific strength and high specific stiffness. In addition, they have good thermal resistance, corrosion resistance, damping resistance, and dimensional stability. But, due to the inhomogeneous composition of these materials, machining of composite materials becomes a major concern in the industry. For the present study, machining was carried out at a CFRP composite pipe with bidirectional carbon fiber. Based on the experimental results, regression analysis was conducted to determine the input-output relationships of the process. A mathematical model was developed to predict the responses, and correlation graphs were plotted. The regression equations were then plotted and the effects of each process parameter on the response were analyzed using the response surface methodology. The process parameters were then optimized using genetic algorithm to yield minimum cutting force and minimum surface roughness.

Investigation on the effects of Cloisite 30B and copolymer (ethylene and butyl acrylate) reinforcement with polypropylene thermoplastic by melt intercalation method

In recent years, the application of polymer nanocomposites has been enormously increased, particularly in aerospace and automotive sector due to its lightweight and high specific strength. In this study, nanocomposite materials with polypropylene (PP) matrix and Cloisite 30B (C30B) as reinforcing nanofiller with Elvaloy AC 3427 (EA) as compatibilizer were manufactured by melt intercalation technique with the aid of twin-screw extruder (TSE). The C30B with EA was reinforced in the PP matrix at 1, 2, 3 and 5 wt%. The PP/C30B/EA nanocomposites were processed in TSE with different barrel zones such as conveying zone, melting zone, mixing zone and plasticizing zone which helps in achieving homogenous dispersion of C30B in PP matrix. The processing parameters of TSE are twin-screw speed (65 r/min), volumetric feeder’s screw speed (7 r/min), degassing zone pressure (40 mmHg), cooling length (50 cm) and humped temperature profile (170–220°C). The processed PP/C30B/EA was characterized using X-ray diffraction (XRD) for studying intercalation/exfoliation structure formation and transmission electron microscope (TEM) for studying the dispersion of C30B in PP matrix. The thermal characterization of PP/C30B/EA nanocomposites was investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The addition of C30B at 5 wt% to PP/C30B/EA nanocomposites increased the DSC, TGA and DMA properties.

Experimental investigation of resistance welded polypropylene nanocomposite joints

Abstract Polymers reinforced with fillers termed as polymer nanocomposites have gained interest among the researchers. In the present research work, the manufacturing of polymeric nanocomposite was carried out with Polypropylene (PP) matrix and 2 wt.% of Cloisite30B (C3B) as nanofiller with Elvaloy AC 3427 (EAC) as compatibilizer by melt intercalation method with the aid of twin screw extruder. The resistance welding samples were produced by injection molding. In this study, resistance welding was used for joining 2 wt.% PP/C3B/EAC nanocomposite using stainless steel as an interlayer. To study the lap shear strength of the joints, an L9 orthogonal array was constructed with input factors like clamping pressure (MPa), time (s) and current (A). The joints were studied metallurgically by scanning electron microscope; which revealed a good integration of 2 wt.% PP/C3B/EAC nanocomposites with the interlayer. The significance of the input factors over the lap shear strength was investigated using Analysis of Variance (ANOVA).

CORROSION PROPERTIES OF CRYOROLLED AA2219 FRICTION STIR WELDED JOINTS USING DIFFERENT TOOL PIN PROFILES

The purpose of this paper is to present the corrosion behavior of the Cryorolled (CR) material and its Friction Stir Welded joints. Due to the thermal cycles of Friction Stir Welding (FSW) process, the corrosion behavior of the material gets affected. Here, the cryorolling process was carried out on AA2219 alloy and CR material was joined by FSW process using four different pin tool profiles such as cylindrical, threaded cylindrical, square and hexagonal pin. The FSW joints were analyzed by corrosion resistance with the help of potentiodynamic polarization test with 3.5% NaCl solution. From the analysis, it is found that CR AA2219 material exhibits good corrosion resistance compared to the base AA2219 material, and also a hexagonal pin profile FSW joint exhibits high corrosion resistance. Among the weld joints created by four different tools, the lowest corrosion resistance was found in the cylindrical pin tool FSW welds. Further, the corroded samples were investigated through metallurgical investigations like OM, Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDX) and X-Ray Diffraction (XRD). It was found that the amount of dissolution of Al2Cu precipitate was present in the weld nugget. The amount of dissolution of Al2Cu precipitate is higher in the weld nugget produced by hexagonal pin tool. This is due to the enhancement of the corrosion resistance.

An Innovative Approach for Optimization of Frictional Vibration Joining Process

The use of frictional vibration for joining of plastic plates by butt welding was studied using the Taguchi methodology. The effectiveness of the Taguchi method lies in clarifying the factor that dominates the complex interactions in frictional vibration welding. The factors are (i) Frequency of tool vibrating across the work piece, (ii) Feed of the work piece against the tool and (iii) Clamping force at the joint interface. This study describes an innovative method of selection of process parameters for obtaining optimal weld tensile strength. Artificial Neural Network was used to establish the relationship between input and output parameters. Genetic Algorithm (GA), Particle Swarm Optimization(PSO) and Taguchi method were used to optimize the parameters for the process.