The Effect of High Loaded Multiwall Carbon Nanotubes in Natural Rubber and Their Nonlinear Material Constants

The aim of this paper is to study the high load of multiwall carbon nanotubes (MWCNTs) in natural rubber (NR) matrix. Firstly, the rubber matrix, fillers, and crosslinker are thoroughly mixed together in two-roll mill. Rheological tests are done from which scorch time, cure time, and cure index are estimated. The kneaded mixer is then compression molded, dumb bell samples as per ASTM D412 are prepared, and tensile strength, tensile modulus, elongation at break, and hardness are measured. It is noticed that NR/30% MWCNT has shown the highest tensile strength of 23.38 MPa and Shore A hardness of 90, which is 78.18% and 91.5%, respectively, higher than the unfilled NR. The increase in strength and hardness, the ductility loss, and decrease in elongation at break are observed upon increase in filler. FTIR, SEM, and AFM examinations are done and the results show high dispersion of nanofillers and strong interfacial interaction with rubber, which is responsible for overall enhancement in mechanical properties of the nanocomposites. Furthermore, the nonlinear material constants are evaluated through extended tube model and corresponding nonlinear material constants of different filler compositions are presented for the designers to use them in their component design and analysis

A review article: investigations on soft materials for soft robot manipulations

In recent years, exploratory research on soft materials and their mechanism has been gaining in popularity. The investigations on soft materials are mostly done for two reasons: (a) to develop an anthropomorphic/prosthetic hand or soft hand with human skin-like material to perform soft manipulations and (b) to develop soft actuators. This paper presented a comprehensive investigation into researches on soft materials for robotic applications. The primary interest of using soft materials is not to leave any marks or damage to objects during the manipulation. The other advantage would be stable grasping due to an area contact. Natural rubber, synthetic rubber, elastomer, polymer composite and nanoparticulated polymer composite are some existing soft materials. Extensive research is required to prepare a highstrength but lighter soft material for robotic soft manipulation. Human skin and its mechanical properties are initially discussed. In addition, the need of soft material for soft manipulations and observations from previous researches over the past few decades, modelling of non-linear hyperelastic/ viscoelastic materials and characterization are discussed. Finally, various soft materials including the polymer-matrix composites, available fillers and their advantages, processing methods and nanoparticulated polymer matrix and its significance in robotic application are presented

Mechanical and Corrosion Properties of Friction Stir Welded and Tungsten Inert Gas Welded Phosphor Bronze

This study investigated the mechanical and corrosion properties of Friction Stir Welded (FSW) and Tungsten Inert Gas (TIG) welded phosphor bronze (CuSn4) joints. Corrosion tests were conducted on the welded joints, and the percentage of weight loss due to corrosion was measured at different time intervals. Results revealed that the percentage of weight loss due to corrosion of the TIG joint increased with time, whereas the percentage of weight loss due to corrosion of the FSW welded joint remained constant. This could be attributed to recrystallisation that happened in the solid-state welding, which reduced corrosion in the FSW welded joint. In addition, tensile tests were conducted to evaluate the strength of the joints. FSW with a spindle speed of 1300 rpm, weld speed of 0.06mm/sec, plunge depth of 0.25mm, pin profile of pentagon, and flat shoulder profile was found to produce good results. TIG welding with a welding speed of 1.75mm/sec, a gas flow rate of 7.5 cm3/min and an amperage of 120A also produced good results. The tensile strength of FSW was found to be approximately 1.6 times higher than that of TIG welding

Prospects of friction stir processed Mg alloys and composites-Reviews and suggestions

The pursuit of advanced materials with enhanced or tailored properties has indeed been a crucial focus in various industries. From aerospace to automotive, and from nuclear power to space exploration, the need for materials that can withstand extreme conditions, offer improved performance, and ensure safety is paramount. Safety standards are vital in industries where materials are subjected to extreme conditions or where failure could have catastrophic consequences. Therefore, research in advanced materials not only focuses on enhancing properties but also ensuring that these materials meet rigorous safety standards. Friction stir processing (FSP) emerges as a transformative methodology, facilitating the achievement of superplasticity, enhanced ductility, heightened strength, toughness, and hardness, all while preserving the structural integrity of the material. In recent years, notable advancements have been witnessed in preparing magnesium (Mg) alloys, Mg composites, and functional Mg materials. This comprehensive review encompasses the latest developments, global significance, adherence to standards, and innovative strides in Mg alloys from 2011 to 2023. It includes the FSP processing techniques, governing mechanism, advantageous properties, grain size, dislocations and their impacts, corrosion, wear behaviour, formability studies, cryogenic FSP, underwater FSP and friction stir additive manufacturing. Readers will gain critical insights, receive constructive suggestions, and discern future directions from this extensive review, as it encapsulates the trajectory of advancements in Mg alloys and delineates promising horizons with potentially transformative impacts in materials science research. Prospects and potential areas would deem help upcoming researchers to pursue with new advanced materials

Influence of SiC Nanoparticle Reinforcement on FSS Welded 6061-T6 Aluminum Alloy

The current research focuses on the mechanical properties and the microstructural behavior of friction stir spot-welded 6061-T6 aluminum alloy reinforced with SiC nanoparticles. Weld samples are produced with and without the addition of SiC nanoparticles to the joint. The microhardness and lap shear strength of the joints are investigated. The cross section of welds and the fracture surfaces are studied by a stereo zoom microscope. Microstructure and distribution of reinforced particles in the stir zone are examined through optical and scanning electron microscopies. It is observed that the reinforcement of SiC nanoparticles significantly influences the grain size and hence the weld properties. The highest hardness of 93 HV and the maximum shear load of 2650.5 N are observed at the stir zone of the sample with 29% SiC. All the weld samples exhibit the similar “W” shape hardness profile. From the observed results, the selected set of process parameters is found adequate in order to fabricate sound Al/SiC composite joints

Drilling Parameters Analysis on In-Situ Al/B₄C/Mica Hybrid Composite and an Integrated Optimization Approach Using Fuzzy Model and Non-Dominated Sorting Genetic Algorithm

In-situ hybrid metal matrix composites were prepared by reinforcing AA6061 aluminium alloy with 10 wt.% of boron carbide (B4C) and 0 wt.% to 6 wt.% of mica. Machinability of the hybrid aluminium metal matrix composite was assessed by conducting drilling with varying input parameters. Surface texture of the hybrid composites and morphology of drill holes were examined through scanning electron microscope images. The influence of rotational speed, feed rate and % of mica reinforcement on thrust force and torque were studied and analysed. Statistical analysis and regression analysis were conducted to understand the significance of each input parameter. Reinforcement of mica is the key performance indicator in reducing the thrust force and torque in drilling of the selected material, irrespective of other parameter settings. Thrust force is minimum at mid-speed (2000 rpm) with the lowest feed rate (25 mm/min), but torque is minimum at highest speed (3000 rpm) with lowest feed rate (25 mm/min). Multi-objective optimization through a non-dominated sorting genetic algorithm has indicated that 1840 rpm of rotational speed, 25.3 mm/min of feed rate and 5.83% of mica reinforcement are the best parameters for obtaining the lowest thrust force of 339.68 N and torque of 68.98 N.m. Validation through experimental results confirms the predicted results with a negligible error (less than 0.1%). From the analysis and investigations, it is concluded that use of Al/10 wt.% B4C/5.83 wt.% mica composite is a good choice of material that comply with European Environmental Protection Directives: 2000/53/CE-ELV for the automotive sector. The energy and production cost of the components can be very much reduced if the found optimum drill parameters are adopted in the production

Drilling Parameters Analysis on In-Situ Al/B4C/Mica Hybrid Composite and an Integrated Optimization Approach Using Fuzzy Model and Non-Dominated Sorting Genetic Algorithm

In-situ hybrid metal matrix composites were prepared by reinforcing AA6061 aluminium alloy with 10 wt.% of boron carbide (B4C) and 0 wt.% to 6 wt.% of mica. Machinability of the hybrid aluminium metal matrix composite was assessed by conducting drilling with varying input parameters. Surface texture of the hybrid composites and morphology of drill holes were examined through scanning electron microscope images. The influence of rotational speed, feed rate and % of mica reinforcement on thrust force and torque were studied and analysed. Statistical analysis and regression analysis were conducted to understand the significance of each input parameter. Reinforcement of mica is the key performance indicator in reducing the thrust force and torque in drilling of the selected material, irrespective of other parameter settings. Thrust force is minimum at mid-speed (2000 rpm) with the lowest feed rate (25 mm/min), but torque is minimum at highest speed (3000 rpm) with lowest feed rate (25 mm/min). Multi-objective optimization through a non-dominated sorting genetic algorithm has indicated that 1840 rpm of rotational speed, 25.3 mm/min of feed rate and 5.83% of mica reinforcement are the best parameters for obtaining the lowest thrust force of 339.68 N and torque of 68.98 N.m. Validation through experimental results confirms the predicted results with a negligible error (less than 0.1%). From the analysis and investigations, it is concluded that use of Al/10 wt.% B4C/5.83 wt.% mica composite is a good choice of material that comply with European Environmental Protection Directives: 2000/53/CE-ELV for the automotive sector. The energy and production cost of the components can be very much reduced if the found optimum drill parameters are adopted in the production