Fluids and lubricants are critical for the mechanical manufacturing processing of metals, due to a high amount of friction generated, also reflected as heat, could wear and damage tooling and machine components. The proper application of lubricants increases machinery lifetime, decreases long-term costs, and energy and time consumption due to the maintenance or components exchange/repairs. Besides being non-renewable, mineral oils bring consequences to the environment due to their low biodegradability and could affect the user with respiratory and skin diseases. Recently, due to an increase in environmental awareness, the search of biocompatible and efficient lubricants has become a technology goal. The vegetable oil-based lubricants are slowly emerging as ecofriendly and high-performance alternatives to petroleum-based lubricants. This study evaluates soybean, sunflower, corn and paraffinic oils reinforced with SiO₂ nanoparticles. The thermal and tribological evaluations were performed varying the temperature and nanofiller concentrations. The thermal conductivity improvements were observed for all nanolubricants as the temperature and filler fraction increased. The highest thermal conductivities were observed at 323 K with 0.25 wt % SiO₂. The soybean and corn oils unveiled a maximum enhancement of ~11%. The tribological evaluations showed that SiO₂ addition, even in small concentration, resulted into a significant improvement on a load-carrying capacity. For instance, at 0.25 wt % enhancements of 45% and 60% were observed for soybean and sunflower oils, respectively. The coefficient of friction performance also showed enhancements between 10% and 26%.

Today, shape memory alloys (SMAs) have important applications in several fields of science and engineering. This work reports the thermomechanical behavior of NiTi SMA coil springs. The thermomechanical characterization is approached starting from mechanical loading–unloading tests under different electric current intensities, from 0 to 2.5 A. In addition, the material is studied using dynamic mechanical analysis (DMA), which is used to evaluate the complex elastic modulus E* = E^′ − iE^″, obtaining a viscoelastic response under isochronal conditions. This work further evaluates the damping capacity of NiTi SMA using tan δ, showing a maximum around 70 °C. These results are interpreted under the framework of fractional calculus, using the Fractional Zener Model (FZM). The fractional orders, between 0 and 1, reflect the atomic mobility of the NiTi SMA in the martensite (low-temperature) and austenite (high-temperature) phases. The present work compares the results obtained from using the FZM with a proposed phenomenological model, which requires few parameters for the description of the temperature-dependent storage modulus E^′.

This paper focuses on studying how mineral oil, sunflower, soybean, and corn lubricants influence friction and wear effects during the manufacturing of aluminum parts via the single point incremental forming (SPIF) process. To identify how friction, surface roughness, and wear change during the SPIF of aluminum parts, Stribeck curves were plotted as a function of the SPIF process parameters such as vertical step size, wall angle, and tool tip semi-spherical diameter. Furthermore, lubricant effects on the surface of the formed parts are examined by energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) images, the Alicona optical 3D measurement system, and Fourier-transform infrared spectroscopy (FTIR). Results show that during the SPIF process of the metallic specimens, soybean and corn oils attained the highest friction, along forces, roughness, and wear values. Based on the surface roughness measurements, it can be observed that soybean oil produces the worst surface roughness finish in the direction perpendicular to the tool passes (Ra =1.45 μm) considering a vertical step size of 0.25 mm with a 5 mm tool tip diameter. These findings are confirmed through plotting SPIFed Stribeck curves for the soybean and corn oils that show small hydrodynamic span regime changes for an increasing sample step-size forming process. This article elucidates the effects caused by mineral and vegetable oils on the surface of aluminum parts produced as a function of Single Point Incremental Sheet Forming process parameters.

Generative design, based on genetic algorithms, creates multiple design solutions for complex structural problems by setting parameters, constraints, objectives, and performance criteria. The aim of this work is to evaluate, through numerical methods, the lightweighting of components manufactured in structural steel by modifying the material, geometry, and the process of manufacture in a generative design system. By characterizing the mechanical properties of an existing structure using finite element methods, objectives and constraints were established to optimize the components through genetic algorithms. In this study, these components were evaluated under static compression loading conditions with different materials, ASTM A36 Steel and Polyphenylene Sulfide. The results showed maximum stresses of 11.20 MPa and 10.76 MPa respectively for each material, with a difference of 0.44 MPa. The optimization process generated 14 iterations for each component, meeting the algorithm's objectives to reduce mass and be manufacturable through injection molding. Resulted in a maximum stress of 11.27 MPa in the optimized components, without exceeding yield strength. Furthermore, a significant mass reduction was achieved, with an 88% reduction in component "A" and 79% in "B." The originality of the study lies in the use of advanced design techniques for optimization not only in terms of geometry, but also material and manufacturing processes. This provides new perspectives and solutions for the fabrication and design of lightweight components manufactured at high volumes. It is concluded that lightweighting of components is feasible through numerical methods and generative design, reducing the mass of the studied components by 80% without sacrificing their mechanical properties, and simultaneously generate geometries feasible for plastic injection molding.