Through the approaches in this article, an attempt was made to analyze the bonding of Al-Cu bimetallic composite layers and the highlight of the diffusion at the boundary between the layers, by hot rolling. An aluminum alloy 6060 plate (EN-AW AlMgSi) and a Cu-ETP ½ hard (CW004A) plate were used. All of these layers of materials were TIG-welded, at both ends, into a heat-treated layered composite and subsequently subjected to the hot-rolling process. The Al-Cu composite material obtained was analyzed by scanning electronic microscopy (SEM) analysis, after being subjected to the tensile test, as well as energy-dispersive X-ray (EDX) analysis. The obtained results highlighted the diffusion at the boundary between the layers of the Al-Cu composite as well as its ductile breakage and the distribution of the amount of Al and Cu at the interface of the layers.
The influence of elevated temperatures and strain rate on the mechanical and structural properties of steel 42CrMo4 were analysed experimentally in this paper. The experiments were based on uniaxial tension and compression tests at high temperatures between 700 °C and 1100 °C and strain rates in the range 0.0018–0.1 s−1. The influence of temperature and strain rate on yield stress, strain to fracture, hardness, structural changes, and fracture characteristics were analysed. The non-uniformity of deformations obtained at different values of the strain rate and temperature were also analysed. Analysis by scanning electron microscopy showed the ductile behaviour of the material. The degree of damage in the material caused by the presence of cavities increased with increasing deformation temperature. For all the presented deformation conditions, the formation of the fracture through the ductile fracture mechanism resulted from localized necking and the coalescence of microvoids. By increasing the deformation temperature and reducing the strain rate, the fracture behaviour of 42CrMo4 steel can be improved.
Fe50Mn35Sn15 Heusler alloy, obtained by mechanical alloying, was subjected to larger milling times in the range of 30–50 h to study the phase stability and morphology. X-ray diffraction studies have shown that the milled samples crystallise in a disordered A2 structure. The A2 structure was found to be stable in the milling range studied, contrary to the computation studies performed on this composition. Using Rietveld refinements, the lattice parameter, mean crystallite size, and lattice strain were computed. The nature of the obtained phases by milling was found to be nanocrystalline with values below 50 nm. A linear increase rate of 0.00713 (h−1) was computed for lattice strain as the milling time increased. As the milling time increases, the lattice parameter of the cubic Heusler was found to have a decreasing behaviour, reaching 2.9517 Å at 50 h of milling. The morphological and elemental distribution—characterised by scanning electron microscopy and energy-dispersive X-ray spectroscopy—evidenced Mn and Sn phase clustering. As the milling time increased, the morphology of the sample was found to change. The Mn and Sn cluster size was quantified by elemental line profile. Electrical resistivity evolution with milling time was analysed, showing a peak for 40 h of milling time.
29 September 2016 in Journal of Manufacturing Science and Engineering
In this paper, the cold simultaneous toothing of spur gears has been investigated. This method can be described as a press-rolling process. The influence of gear geometry such as teeth number and the deformation mechanism was investigated by 3D finite-element analysis using forge® software in terms of teeth forming and forming loads evolution. Based on these simulations, the experimental investigations were carried out to obtain a spur gear form with the good quality, using several billet dimensions. The experimental trials and simulations conducted for the spur gear (z = 23 teeth and m = 1.5 mm) showed premises to continuous flow lines formation at the base of the teeth. The maximum pressing force results from the numerical simulation agree with the experimental maximum force recorded.
A Ni2MnSn Heusler alloy was obtained as a single B2 phase after 12 h of mechanical milling. The influence of prolonged milling on the phase stability was analysed for milling times up to 50 h, related to mean crystallite size, lattice strain, and electrical resistivity. The nature of the powders in the milled range was found to be nanocrystalline, with a mean crystallite size of about 33 ± 2 nm. An evaluation of the internal stresses induced by milling was performed, a linear behaviour was found, and a coefficient of the internal stress increase with milling time was proposed. Particle size distributions of milled samples were analysed, and the morphology of the powders was visualised by scanning electron microscopy. The elemental distribution of milled samples was quantified by energy-dispersive X-ray spectroscopy. Electrical resistivity measurements were performed on compacted samples, and their behaviour with milling time was analysed.
The purpose of this paper is to present a vibration dissipation device that sends vibration signals from the manipulated tool in the workplace to the operator’s hand by improving its ergonomic appearance and materials. Compared with another vibration dissipation device, this one was previously designed and patented. This paper is based on two studies: one theoretical and the other experimental (the latter regarding the material used). The first part is represented by the design and simulation of the device and a static analysis by FEA in SolidWorks 2022. The stresses to which the materials of the device’s bracelets are subjected are studied in this article; then, the resistance of the device’s materials to the tensile and deformation stresses they are subjected to is presented. All these studies complement DIAV equipment’s functionality in terms of its components’ design and assembly. Emphasis is placed on its shape and ease of assembly and the operator’s dexterity in mechanical processes so that DIAV does not limit them. In addition, from the point of view of its design, emphasis is placed on its fixation so that it is easy to assemble and is within reach of any operator. The appropriate choice of materials for the components of the DIAV device is of major importance both in terms of strength, ergonomics, and weight. The experimental results validate the theoretical results obtained through the FEA simulation in SolidWorks, and this fact confirms the usefulness and functionality of the DIAV device from the perspective of vibration attenuation.