Functional Composite Materials: Manufacturing Technology and Experimental Application

In this study, CNC turning process parameters are optimized while machining AA6061 – T6 alloy. The process variables, namely, cutting spindle speed or spindle velocity (Cs), rate of feed (Fr), rate of the depth of cut (Dc), and nose radius (Nr), were optimized with output responses such as surface roughness (Ra), feed power (Fx), thrust power (Fy), cutting power (Fz), and removal rate of material (MRR). The optimized results showed higher MRR, Fy, and Fz and lower Fx and Ra were obtained at a cutting spindle speed or spindle velocity (Cs) of 100 rev/min, rate of feed (Fr) of 0.2 mm/min, depth of cut (Dc) of 1.5 mm/min, and nose radius (Nr) of 0.8 mm. TOPSIS and ANOVA were used to assess the experimental results to determine the most favourable factors that were superior and suitable for selecting the optimal variable condition.

Powder mixed electrical discharge machining (PMEDM) is applied for machining complex parts that cannot be machined by conventional machining processes. In this work, the optimization of PMEDM process parameters for Monel K 500 was performed, and its impact was analysed. PMEDM experiments were planned using the L’9 orthogonal array with pulse-on-time, pulse-off-time, and current as input parameters. The output parameters were material removal rate (MRR), tool wear rate (TWR), and surface roughness. Using a combination of principal component analysis (PCA) and grey relational analysis (GRA), the outcome was optimized. The analysis of variance was used to analyze the impact of input parameters over the output parameters. Finally, confirmation tests were performed to confirm the optimized output values of the machining process. 

Joining sheet metals using the spot welding process is the most economical and commonly employed method by the manufacturing industries in producing automotive and aerospace components. This research analyzes the joining of stainless steel of grade EN 1.4301 (AISI 304) welded with EN 1.4435 (AISI 316L) in the cross tension configuration. Four different process parameters, electric current, contact pressure, heating, and squeezing time, are analyzed in the present study. The integrity of the cross lap joints is evaluated by cross tension failure tests and metallurgical analysis. The results are evaluated, and optimal process parameters are obtained by design expert software. A confirmation test is carried out to verify the optimum parameters. It has been found that the electric current is the most influential factor, and a maximum of 14.85 kN cross tension failure load is obtained. The mathematical model developed using the response surface methodology (RSM) has an R2 value of 95.03%, compared with the results of the multilayered ANN model with four neurons in the interface layer. ANN proved to be a slightly better model with an R2 value of 97.6%.

 A lot of research has been carried out over the past decades to develop an appropriate material that meets the rising demands of the industries. Aluminium is one of the most commonly used lightweight materials because of its corrosion resistance, soft ductility, and excellent electrical conductivity. However, aluminum is not efficient in high thermal loads due to its soft nature. Metal Matrix Composites (MMCs) are being built to address this drawback, which is a new class of engineering materials in which aluminum alloys are being used as a matrix. Hard ceramic particles (SiC, B4C, Al2O3 & ZrB2 ) are generally used as reinforcement phases. Such MMCs based on aluminum have enhanced mechanical properties such as high strength-to-weight ratio, better wear resistance, good fatigue resistance, and outstanding corrosion resistance, making them ideal for use in various fields such as marine, automotive, aerospace, and defense. Among different casting technologies, stir casting technology may be used because of its easy fabrication method and low manufacturing cost.

In the current manufacturing scenario, conventional machining processes play a broad role in manufacturing composite materials. In this research work, an end milling operation was carried out on reinforced epoxy granite composites. Experiments based on aggregate type, fiber content, spindle speed, and feed rate were performed using the Taguchi method. By undergoing a multi-level design, the L27 orthogonal array of Taguchi was obtained. Based on this design of experiment, an end milling operation was performed on prepared epoxy granite samples. The response constraints such as thrust force and surface roughness values were measured by appropriate measuring instruments. The outcome of system constraints was optimized based on response constraints. The optimization was performed through the multi-attribute decision-making technique for order preference by similarity to ideal solution. The ideal process constraints of spindle speed and feed rate were found 1200rpm and 60mm/min, respectively, which produce a better surface finish with minimal thrust force. Analysis of variance was used to verify the influence of process constraints on outcome response. 

 Aerogels are highly porous nanostructures with very low density and have various applications. This research study aims to synthesize carbon aerogels using a sol gel poly-condensation reaction. The primary precursors were resorcinol with formaldehyde in a molar ratio of 1:2 using base catalyst sodium carbonate to produce carbon aerogels. The density obtained for synthesized Resorcinol Formaldehyde (RF) aerogels was 40-50kg/m3 . The carbonization of resorcinol formaldehyde aerogels was carried out using pyrolysis under 800oC with a heating rate of 10oC/min under vacuum conditions after the carbonization porosity of the aerogel was increased. The surface morphology was characterized using Field Emission Scanning Electron Microscopy (FESEM), and elemental analysis was carried out using X-Ray Photoelectron Spectroscopy (XPS). From the final results, it was observed that the carbonization of the resorcinol formaldehyde aerogels by pyrolysis increased the porosity of the carbon aerogels. Thus, it could be predicted that these carbon aerogels can serve as a promising applicant for future water treatment. 

This study has been carried out to demonstrate the tribological behavior of
natural fiber-based polyester hybrid composite with novel filler materials. The
reinforcement fibers considered in this study are Jute and Coir fiber. The filler
materials selected in this work are copper slag (final waste from the copper extraction)
and Nanoclay (Montmorillonite K10). The percentage of both reinforcement fibers and
fillers has been changed, and the analyses have been carried out. Experiments were
conducted on the specimen based on Taguchi’s design of experimental technique. L9
Orthogonal array is selected for analysis, and Grey Relational Analysis (G.R.A.) is
introduced to determine the better combination of reinforcement and filler to provide
better wear resistance and coefficient of friction. Also, a statistical analysis is
performed to find the influence of input parameters.