The biodegradability and comparatively less harmful degradation of polylectic acid (PLA) make it an appealing material in many applications. The composite material is used as a feed for a 3D printer, consisting of PLA as a matrix and graphene (3 wt.%) as reinforcement. The composite is extruded in the form of wires using a screw-type extruder machine. Thus, prepared wire is used to 3D print the specimens using fused deposition modeling (FDM) type additive manufacturing technology. The specimens are prepared by varying the different process parameters of the FDM machine. This study’s primary objective is to understand the tribological phenomena and surface roughness of PLA reinforced with graphene. Initially, pilot experiments are conducted to screen essential factors of the FDM machine and decide the levels that affect the response variables, such as surface roughness and wear. The three factors, viz., layer height, printing temperature, and printing speed, are considered. Further experiments and analysis are conducted using the Box–Beheken method to study the tribological behavior of 3D-printed composites and the effect of these parameters on surface roughness and wear loss. It is interesting to note that layer height is significant for surface roughness and wear loss. The optimum setting for minimum surface roughness is layer height at 0.16 mm, printing temperature at 180 °C, and printing speed at 60 mm/s. The optimum setting for minimum wear loss is layer height at 0.24 mm, printing temperature at 220 °C, and printing speed at 90 mm/s. The desirability function approach is used to optimize (multiobjective optimization) both surface roughness and wear loss. The layer height of 0.16 mm, printing temperature of 208 °C, and printing speed of 90 mm/s are the optimum levels for a lower surface roughness and wear loss. The SEM images reveal various wear mechanisms, viz., abrasive grooves, micro-fractures, and the presence of wear debris. The work carried out helps to make automobile door panels since they undergo wear due to excessive friction, aging, material degradation, and temperature fluctuations. These are taken care of by graphene addition in PLA with an optimized printing process, and a good surface finish helps with proper assembly.

New biomedical supportive and lightweight structures require the creation of sustainable polymer composites of high strength and wear resistance. This research explores the use of alkali-treated pineapple leaf fiber (PALF) reinforced epoxy composites and determines complete structure property wear relationships using combined mechanical, tribological, and microstructural analysis. The novelty of the work is based on the correlation of fiber content with the stiffness increment, the damage tolerance, and degradation behavior under friction conditions at controlled fabrication conditions. A hand lay-up method was used to manufacture composite laminates with 5-25 wt.% PALF. The tensile strength rose to 78 MPa and Youngs modulus rose to 3.5 GPa. Flexural strength increased to 112 MPa and flexural modulus to 3.7 GPa. The energy impact decreased by 12 and dropped to 20 kJ/m2 and Shore D hardness rose by 72 and 76, respectively, which means the increase in deformation and surface damage resistance. Tribological testing revealed that coefficient of friction and wear rate decreased to 0.51 and 3.7 x 10-6 mm 3/N-m respectively by fiber-supported load distribution and establishment of protective transfer films. The scanning electron microscopy showed that there was consistent fiber dispersion, good bonding of fiber matrix, and predominance of crack-bridging and pull-out processes involving the fracture resistance. The best mechanical tribological behavior was observed with a concentration of 10-15 wt.% PALF. A further study will involve biocompatibility studies, long-lasting stability, and surface functionalization to permit biomedical assistance elements like orthotic braces, prosthetic frames, and non-load-bearing auxiliary medical components.

The present study focused on a comparative analysis of NaOH-treated and untreated Sida acuta fiber-reinforced composites with respect to their wear behavior and compressive strength. The Sida acuta fibers were treated with 5% NaOH, while the untreated fibers were used directly as reinforcement, both comprising 32 ± 1 wt.% of the epoxy matrix composites. The composites were further characterized based on their average density, hardness, and compressive strength. Additionally, weight loss, volume loss, and wear rate were examined under dry wear test conditions across various loads and sliding velocities. The results indicate that the alkali-treated fiber-reinforced composite exhibits superior hardness (84.3 ± 2.0) and compressive strength (99.89 ± 3.92 MPa), representing improvements of 12.57% and 13.5%, respectively, over the untreated fiber-reinforced composite. Moreover, the 5% NaOH-treated fiber-reinforced composite demonstrated lower wear rates compared to its untreated counterpart. Scanning Electron Microscopy (SEM) was employed to examine the dry wear surface morphology of both composite laminates, providing insights that support the observed test results. Overall, the developed Sida acuta composite exhibits promising properties, making it suitable for lightweight and medium-strength structural applications.

This research paper explores the performance of electrorheological fluids, widely known as smart fluids, which are popular because they experience immediate changes in their characteristics when applied to exterior magnetic or electric field. On application of high voltage, the ER fluid alters its form to semisolid from viscous liquid within a few milliseconds, which is reversible. The reversible nature of ER fluid was employed to absorb vibrations during hard machining. In this research, the consequence of the application of electric field to the ER characteristics of numerous non‐Newtonian fluids with an accumulation of TiO₂ and Al₂O₃ nano elements are investigated. The purpose of this research is to discover the ER sample, which has the highest viscosity, highest breakdown voltage, but less sedimentation. So the selected sample can be used in ER dampers for the purpose of shock absorption. The ER fluid behaves as a mainspring with nonlinear vibration features that are managed by an arrangement of ER fluid, the structure of plunger, and the constraints of applied electric field. In this research, we have employed steel metallic specimens made from EN24T of 302BHN and the machining experiments are conducted to attain the shape parameters that can reduce the tool vibration and help improve the process of cutting at the time of machining with minimum application of fluid utilizing hard metal inserts. In this work, cutting tool parameters were analyzed like cutting force, tool wear, tool vibration amplitude, and surface roughness. It was observed that ER damper has shown its better performance at 5KV. At 5KV, cutting force was the least, tool wear was the least, tool vibration amplitude was the least, and surface roughness was the least. The use of an ER fluid damper decreases tool vibrations and successfully enhances machining performance. The machining industry will be benefited with commercialization of this technique.