Papers by Keyword: Lightweight

Abstract: Hybrid joints made of steel and aluminium alloy produced by rotary friction welding enable load-adapted lightweight components. However, a major challenge is the inhomogeneous radial temperature distribution caused by different relative velocities between the specimen centre and edge during rotation. This effect leads to local insufficient bonding and reduces the overall joint strength, especially in the centre, where low relative rotation speeds occur. Previous studies mainly addressed preheating before the friction phase, whereas superimposed heating during the upsetting phase has not been investigated so far. To achieve temperature equalisation along the cross-section during rotary friction welding, a modified KUKA Genius plus machine equipped with joule heating was used to introduce an electric current during the upsetting phase. Experiments were conducted on EN AW-6082 (AA-6082) joined to 20MnCr5 (AISI 5120H). A three-step variation of current intensity (10, 24 and 36 A/mm²), alongside a reference without current, was investigated. Temperatures were monitored using type K thermocouples, confirming temperature equalisation. Mechanical performance was assessed by uniaxial tensile tests, while hardness measurements and metallographic analyses characterised the influence of superimposed heating on the interfacial microstructure. Joint strength improves up to 17% with increasing current, even under otherwise unsuitable welding parameters that would normally result in insufficient bond strength. This improvement is linked to a uniform temperature distribution and enhanced material flow, resulting in a defect-free specimen centre.

Abstract: The automotive industry faces a significant challenge in meeting the increasing demand for lightweight and eco-friendly vehicles with reduced energy consumption and lower air pollution. This challenge is driven by factors such as consumer preferences, strict government regulations, technological complexities, cost considerations and market acceptance. Aluminium metal matrix composites (AMMCs) are novel materials with high suitability to address this challenge. Currently, AMMCs used in the automotive industry are reinforced with conventional synthetic ceramic particulates and they have shown tremendous improvements over unreinforced alloys. These composites have wear resistance and strengths equivalent to that of cast iron but with about 67% less density. However, synthetic reinforcements are expensive, have limited availability, possess high abrasiveness, cause unwanted reactions, pose recycling difficulties and their production leads to the emission of greenhouse gases. It is now pertinent to consider the use of agricultural waste derivatives as possible substitutes for these conventional reinforcements. In this work, the various agricultural waste derivatives that have been used to reinforce Al matrixes were reviewed and the potentials of the resulting composites as promising candidates for lightweight automotive applications were assessed. It was concluded that agricultural waste derivatives contained hard ceramics particles which improved the mechanical, tribological, thermal and corrosion properties of AMMCs, making agro-waste derivatives reinforced aluminium metal matrix composites promising for the production of novel lightweight automotive components.

Abstract: In this paper, a novel lightweight and low-cost Al₃₅Mg₂₀Zn₁₅Cu₁₀Si₂₀ at. % (Al_26.17Mg_13.47Zn_27.18Cu_17.61Si_15.57 wt.%) has been successfully designed, produced, and characterized. The thermophysical parameters were used to understand the phases associated with this alloy that show a low density of 3.42 g/cm³. The designed alloy was manufactured using both the arc and the muffle furnace. The alloy was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS). The alloy is characterized by a multiphase microstructure with three major phases including Mg₂Si intermetallic phase and eutectic. The volume fraction of the eutectic and the intermetallic phases are 37.83 and 34.99 respectively. The heat capacities of the alloy were also determined by means of differential scanning calorimetry (DSC). The alloy provides a high latent heat of up to 124 J/g, which is one of the highest among the high-temperature metallic materials. The present work provides valuable information for researchers wishing to design and manufacture industrial-grade high-entropy alloys (HEAs).

Abstract: Lightweight refractory materials are most used as a second layer in the lining. Many techniques can be used to their production depending on their final application. This manuscript is focused on utilization of sol-gel method as the replacement of hydraulic or ceramic bond in the manufacturing process of grog and castable preparation. The results show possible ways to produce high quality lightweight refractory grog with very high purity and also lightweight refractory castable, which performs good results in terms of bulk density, apparent porosity, cold crushing strength, cold modulus of rupture and permanent linear changes.

Abstract: It is known that natural designs are more efficient and functionality-aimed than human designs. Historically, human beings have tried to mimic the way nature designs or the natural designs themselves. However, it turned out that it was usually too complex for the technology of the time. Today there exists the opportunity to mimic most natural designs due to advances in computational power and improvements in manufacturing methods. This can lead to a major weight reduction in the metallic components used, which is a key aspect in many engineering areas such as the aerospace, automotive or energetic industries. This study shows how these bioinspired designs can improve designer experience-based designs in several ways i.e.: mechanical behavior, part number reduction, weight reduction, etc. The components analyzed here will be metallic based on aluminum. It will be also shown the significance of the manufacturing-oriented design so the iteration times are reduced between the CAD and the CAM or the reduction of prototype manufacturing itself. Of course, these designs need to be validated mechanically via CAE and the CAM will also be used to avoid uncertainty during advanced manufacturing processes. Finally, the results of the real manufacturing process are going to be shown so the end-to-end cycle is complete.

Abstract: The fabrication of co-cured metal/CFRP joints offers some relevant advantages as the elimination of adhesives and the simplification of building process. In this view, the additive manufacturing (AM) of metal parts is suitable for expanding the potentialities of co-cured AM metal/CFRP joints where patterned surfaces are introduced. This paper presents a methodology to fabricate the joint, based on matrix patterns of 3D features on the metal surface, which is able to improve the polymer matrix adhesion and to provide carbon fibers engagement. Both FEM simulations and experiments show significant enhancement of the global mechanical strength.

Abstract: Drilling equipment is the key of oil and gas drilling development. Its manufacturing quality and service performance have important influence on oil and gas drilling development safety. The application of high strength grade steel plays an important role in improving drilling equipment manufacturing level and service performance. In this paper, the chemical composition, microstructure, tensile properties, impact properties and hardness of TMCP Q550D and Q-T Q550D high-strength low-alloy steel were tested and compared, and the application feasibility for drilling equipment manufacture was analyzed comprehensively. The experimental results show that the mechanical properties of Q550D by two different methods were obviously higher than the requirement of national standard. Q550D steel had excellent plasticity and toughness, which meets the requirement of drilling equipment manufacture. The main difference between different steel lied in their chemical composition and micro-structure. Carbon content of TMCP Q550D steel plate was lower than that of QT Q550D, and TMCP Q550 was mainly depend on TMCP technology and micro-alloy elements, whose micro-structure was mainly granular bainite. Q-T Q550D was mainly depend on Q-T technology, and its microstructure was tempered sorbite with obvious banded structure and slightly low toughness.

Abstract: This paper deals with three types of triplex steel, where containing 25 to 28 wt.% manganese, 0.8 to 0.89 wt.% Carbon, 9.9 to 11.11 wt.% Aluminum, and with different Nickel content. Two types contain Ni in range of 0.9 to 2 wt.% and third type doesn’t contain Ni. The precipitation of Nano-size kappa carbides is the most proper technique used for this objective. It is expected that inter-metallic strengthening mechanism should act more effective in promoting the strength of Triplex steel with ductility. From this point of view, this research was designed to study the effect of inter-metallic inductive alloying element as Nickel on promoting of the strength and ductility of the high aluminum containing high manganese steel. Optical microscope, scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to detect of inter-metallic precipitates through steel investigated ranged in Nickel from 0 to 2 wt.%. Mechanical and strain hardening properties were determined in the steel investigated after different regimes of heat treatment. It was found that Ni₃Al inter-metallic compound provides the austenite matrix with good strength and ductility, depending on the ageing time. Further deterioration was obviously observed in the steel investigated as increasing the ageing time, attributing to coarse structure occurrence.

Abstract: Derrick and substructure is one of rig’s core equipment components, and it is also the most important weight component of rig. The working environment of derrick and substructure is very serious, whose material should has high strength, excellent plasticity, toughness and weldability property. In this paper, the chemical composition, micro-structure, tensile property, impact property, hardness and weldability of high strength pipeline steel with strength grades of X70 (485MPa)~ X100(690MPa) were systematically analyzed. The analysis and study of the service environment of rig derrick and substructure as well as the technical requirements of the material, showed that the performance of high strength pipeline steel was obviously better than that of the same grade high strength low alloy structural steel used in rig derrick and substructure at present, and it can fully meet the technical requirement of rig derrick and substructure. The application of high strength pipeline steel to rig derrick and substructure will improve the service property, optimize the design , and fully ensure the service safety of rig derrick and substructure.

Abstract: One of the heat-resistant solutions effective application areas is to protect the structures from the high temperatures’ effects in case of fire. Material damage from fires amounts to hundreds millions of rubles. An effective way to improve the fire resistance of the building structures is to apply heat-insulating coatings to the surface. One of the compositions to protect the structures from high temperatures is a heat-resistant solution based on the expanded clay sand and perlite. The effectiveness of the solutions application to protect against high temperatures exposure increases due to the fact that these solutions perform both thermal and decorative functions. In the field of conventional building structures protection from the high temperatures effects, the extensive studies have been carried out by such scientists such as [6,7,8,9,32,10], and the solutions that simultaneously perform the decorative functions and the functions of protection against the effects of high temperatures in the event of fire have been little studied except for the usual restoration solutions. The study of the solutions’ special properties for the protection of small architectural structures such as fire resistance, thermal conductivity and linear thermal expansion coefficient is a rather important task.