Suganeswaran Kandasamy, Parameshwaran Rathinasamy, Nithyavathy Nagarajan, Karthik Arumugam, Rajasekar Rathanasamy and Gobinath Velu Kaliyannan
This paper aims to overcome the corrosion in AA7075 by incorporating the dual-reinforcements like Al2O3 and SiC through friction stir processing (FSP). In recent days, an…
Abstract
Purpose
This paper aims to overcome the corrosion in AA7075 by incorporating the dual-reinforcements like Al2O3 and SiC through friction stir processing (FSP). In recent days, an automotive monocoque structure undergoes corrosion because of changes in environmental conditions.
Design/methodology/approach
Surface hybrid composites (SHCs) of AA7075 with different weight ratios of Al2O3 and SiC were fabricated at a rotating speed of 1000 rpm, traveling speed of 56 mm/min and tool tilt angle of 2º with two passes. Surface regions were observed using optical microscopy, and the potentiodynamic corrosion test was performed under a 3.5 per cent NaCl environment at room temperature. Then, the surface morphology analysis of corroded samples and their structural properties were also investigated through scanning electron microscopy (SEM), X-ray diffraction (XRD) and electron dispersive spectroscopy (EDS).
Findings
Through FSP, an improved interface between the reinforced particles and the AA7075 base matrix was observed because of the severe plastic deformation. Potentiodynamic polarization tests confirmed that the AA7075 matrix with a higher concentration of Al2O3 and a lower concentration of SiC (Al2O3 – 75 per cent and SiC – 25 per cent) possesses a lower corrosion rate than other specimens. This result is because of the combined effect of stable passive film formation and the resistance produced by hard SiC particles. In addition, the formation of a stronger interface between the reinforcements and the base matrix impedes the NaCl solution attack. The SEM micrograph depicts the film crystallinity variations with an increase in Al2O3 content. Debonding between the layers was observed on increasing the SiC content in the base matrix. XRD shows the peaks of reinforcing elements that influence the corrosion behavior. These observations suggest that the AA7075 reinforced with a higher concentration of Al2O3 and a lower concentration of SiC through FSP affords a suitable solution for automotive monocoque applications.
Originality/value
The corrosion rate has been identified for AA7075 SHCs with various concentrations of Al2O3 and SiC and has been compared with that of the base metal and the friction stir processed specimen without reinforcement.
Details
Keywords
S. Raj Sachin, T. Kandasamy Kannan and Rathanasamy Rajasekar
The purpose of this study is to carry out an investigation of the role of the wood particle size on the mechanical properties of poly lactic acid (PLA)-reinforced neem fiber…
Abstract
Purpose
The purpose of this study is to carry out an investigation of the role of the wood particle size on the mechanical properties of poly lactic acid (PLA)-reinforced neem fiber biocomposite.
Design/methodology/approach
Composite test specimens were processed by reinforcing neem wood flour (NWF) in two different particle sizes, micro-sized NWF (MNWF) and nano-sized NWF (NNWF) separately into PLA. Composites were extruded at four different fiber loadings (10, 15, 20 and 25 Wt.%) into PLA matrix. The MNWF and NNWF had particle sizes varying from 5 to 15 µm and 10 to 15 nm, respectively.
Findings
Tensile strength, flexural strength and impact strength of PLA increased with fiber reinforcement for both the MNWF and NNWF cases. The NNWF-reinforced PLA composite at 20 Wt.% fiber loading proved to be the best composite that had outstanding mechanical properties in this research.
Practical implications
The developed composite can be used as a substitute for conventional plywood for furniture, building infrastructure and interior components for the automobile, aircraft and railway sectors.
Originality/value
A new biocomposite had been fabricated by using PLA and NWF and had been tested for its mechanical characteristics.
Details
Keywords
Mohan Prasath Mani and Saravana Kumar Jaganathan
This study aims to fabricate an electrospun scaffold by combining radish (Ra) and cerium oxide (CeO2) into a polyurethane (PU) matrix through electrospinning and investigate its…
Abstract
Purpose
This study aims to fabricate an electrospun scaffold by combining radish (Ra) and cerium oxide (CeO2) into a polyurethane (PU) matrix through electrospinning and investigate its feasibility for cardiac applications.
Design/methodology/approach
Physicochemical properties were analysed through various characterization techniques such as scanning electron microscopy (SEM), Fourier transforms infrared transforms analysis (FTIR), contact angle measurements, thermal analysis, atomic force microscopy (AFM) and mechanical testing. Further, blood compatibility assessments were carried out through activated partial thromboplastin time (APTT) and prothrombin time (PT) and hemolysis assay to evaluate the anticoagulant nature.
Findings
PU/Ra and PU/Ra/CeO2 exhibited a smaller fibre diameter than PU. Ra and CeO2 were intercalated in the polyurethane matrix which was evidenced in the infrared analysis by hydrogen bond formation. PU/Ra composite exhibited hydrophilic nature whereas PU/Ra/CeO2 composite turned hydrophobic. Surface measurements depicted the lowered surface roughness for the PU/Ra and PU/Ra/CeO2 compared to the pristine PU. PU/Ra and PU/Ra/CeO2 displayed enhanced degradation rates and improved mechanical strength than the pristine PU. The blood compatibility assay showed that the PU/Ra and PU/Ra/CeO2 had delayed blood coagulation times and rendered less toxicity against red blood cells (RBC’s) than PU.
Originality/value
This is the first report on the use of radish/cerium oxide in cardiac applications. The developed composite (PU/Ra and PU/Ra/CeO2) with enhanced mechanical and anticoagulant nature will serve as an indisputable candidate for cardiac tissue regeneration.