Numerical investigation on crack analysis of H13 fixed die and structural analysis of moving die with two different materials

Die casting is forcing molten metal into a mould with high pressure. Die casting has two dies namely moving die and fixed die where the moving one will move over the fixed die. Die casting is majorly used for high-volume production. This paper focused on the physical phenomenon of die casting for two dies (moving die and fixed die) using two different alloy materials with variable material chemical compositions. The numerical analysis is carried out for the die casting process to determine the crack formation zone by temperature distribution and structural analysis by stress-strain relationship. The numerical analysis is carried out for both the dies. The fixed die is analyzed with an H13 tool steel material with two moving die materials as aluminum alloy (A356) and magnesium alloy (AZ91D). Both the dies (fixed and moving) were designed by using design software and meshing is carried out followed by analysis using the analysis software. The physical parameter for the dies is applied that is temperature distribution is carried out by applying a temperature of 850 °C and 650 °C over the fixed die for aluminum and magnesium alloy, respectively. Structural analysis is carried out for the moving die with a load of 1,000 N for both aluminum and magnesium alloys with 1000 number of iterations. The results from the numerical analysis are derived and analyzed for both temperature distribution and structural analysis. The crack formation zone is found out by means of temperature gradient and the stress-strain relationship is found out by means of structural analysis. From the results, it was concluded that the crack zone is obtained at 1.22E-10 °C/mm and 6.856E-14 °C/mm of thermal gradient and structural analysis in terms of maximum stress of 446.94 MPa and 448.52 MPa for aluminum and magnesium alloys, respectively.

The Influence of Tool Wear on the Mechanical Performance of AA6061-T6 Refill Friction Stir Spot Welds

The Refill Friction Stir Spot Welding (RFSSW) process—an alternative solid-state joining technology—has gained momentum in the last decade for the welding of aluminum and magnesium alloys. Previous studies have addressed the influence of the RFSSW process on the microstructural and mechanical properties of the AA6061-T6 alloy. However, there is a lack of knowledge on how the tool wear influences the welding mechanical behavior for this alloy. The present work intended to evaluate and understand the influence of RFSSW tool wear on the mechanical performance of AA6061-T6 welds. Firstly, the welding parameters were optimized through the Designing of Experiments (DoE), to maximize the obtained ultimate lap shear force (ULSF) response. Following the statistical analysis, an optimized condition was found that reached a ULSF of 8.45 ± 0.08 kN. Secondly, the optimized set of welding parameters were applied to evaluate the wear undergone by the tool. The loss of worn-out material was systematically investigated by digital microscopy and the assessment of tool weight loss. Tool-wear-related microstructural and local mechanical property changes were assessed and compared with the yielded ULSF, and showed a correlation. Further investigations demonstrated the influence of tool wear on the height of the hook, which was located at the interface between the welded plates and, consequently, its effects on the observed fracture mechanisms and ULSF. These results support the understanding of tool wear mechanisms and helped to evaluate the tool lifespan for the selected commercial RFSSW tool which is used for aluminum alloys.

Current Trends in Automotive Lightweighting Strategies and Materials

The automotive lightweighting trends, being driven by sustainability, cost, and performance, that create the enormous demand for modern lightweight materials and design concepts, are assessed as a part of the circular economy solutions in modern mobility and transportation. The current strategies that aim beyond the basic weight reduction and cover also the structural efficiency as well as the economic and environmental impact are explained with an essence of guidelines for materials selection with an eco-friendly approach, substitution rules, and a paradigm of the multi-material design. Particular attention is paid to the metallic alloys sector and progress in global R&D activities that cover the “lightweight steel”, conventional aluminum, and magnesium alloys, together with well-established technologies of components manufacturing and future-oriented solutions, and with both adjusting to a transition from internal combustion engines to electric vehicles. Moreover, opportunities and challenges that the lightweighting creates are discussed with strategies of achieving its goals through structural engineering, including the metal-matrix composites, laminates, sandwich structures, and bionic-inspired archetypes. The profound role of the aerospace and car-racing industries is emphasized as the key drivers of lightweighting in mainstream automotive industry.

Influences of Welding Parameters on Friction Stir Welding of Aluminum and Magnesium: A Review

Friction stir welding (FSW) is an important joining process wherein two dissimilar metals and alloys are welded together using frictional heat produced in a revolving tool and workpiece. FSW is playing an important role in dissimilar material joining of Magnesium (Mg) and Aluminum (Al) materials due to the increasing demand for their industrial applications. In this review article, the research background of FSW processes, and influences of joining factors on tensile strength, micro-hardness, and microstructures of FSW of Al-Mg alloy materials have been studied. The effects of joining factors for example axial force, tool revolving speed, tool incline, speed, and offset on welding characterizes have been enlightened to make defect-free FSW of aluminum and magnesium alloys. The microstructural behaviors of intermetallic formation and material drift in FSW zones of Al-Mg were also studied to find the scope to improve the welding quality.

Digital reference images when evaluating the quality of castings from aluminum and magnesium alloys

Reference X-ray images of defects in castings and welded joints have been used for many years in X-ray radiation inspection. With the transition to digital technologies, and the use of flat-panel detectors instead of radiographic film, the problem arose of creating reference digital images. Comparison of the digital image of the reference sample with the digital image of the test object can be carried out using software, which completely or partially excludes the subjective assessment of the operator, makes it possible to view doubtful areas of the image with magnification and without loss of contrast, automatically show the size of the defect, its intensity distribution by volume of the casting. All this makes the control more objective and productive. The reference images in the detector’s memory do not undergo the aging and degradation typical of X-ray images, and there is no need to replicate them.

THE RESEARCH OF IGNITION AND COMBUSTION OF ALUMINUM AND MAGNESIUM ALLOYS IN THE PRODUCTS OF DECOMPOSITION OF SOLID PYROTECHNICAL FUELS

The results of experimental research of processes of ignition and combustion of particles of aluminum and magnesium alloys in gaseous purges of high-temperature decomposition of solid pyrotechnic fuels leading to their fire explosive hazardous development are presented. The relevance of these research is due to the wide scope of application of pyrotechnic products based on pyrotechnic mixtures of powders of aluminum-magnesium alloys with additives of organic substances, in particular applications in military technology and use in various industries related to the rotation of solid pyrotechnic equipment. Accordingly, in case of fire at facilities where pyrotechnic products are kept or during their transportation there exists the risk of ignition of pyrotechnic mixtures with different acceleration of their subsequent combustion process and destruction of the pyrotechnic products. As a result, high-temperature combustion products are formed, which are fire hazardous to the surrounding environment. Based on the foregoing, it is necessary to obtain data on the regularities of ignition and combustion particles of aluminum-magnesium alloys, which determines the ability to predict the properties of fire hazard pyrotechnic mixtures. As a result of conducted research, data on the ignition and combustion of particles of aluminum-magnesium alloys was obtained, in particular, the dependence of the delay time of the particles of aluminum-magnesium alloys on their chemical composition was obtained, the data on the process of combustion of particles of aluminum-magnesium alloys was obtained, the data on the effect of additives to aluminum-magnesium alloys was obtained.