The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The deterioration processes of aeolian sand powder concrete under freeze–thaw and dry–wet conditions have been studied. The pore characteristics, hydration products, and micro-morphology were analyzed by nuclear magnetic resonance, x-ray diffraction, and field emission scanning electron microscopy. The results showed that the relative dynamic elastic modulus and corrosion resistance coefficient for...
Extrusion products with ideal microstructure and mechanical properties can be obtained by precise design of the mold cavity structure. In this study, two interim dies were taken as a sample to investigate the texture of typical locations of AZ31 magnesium alloy produced by continuous variable cross-section direct extrusion (CVCDE). The results show that grains were refined significantly after the...
Through the precise design of the mold cavity structure, the ideal microstructure and mechanical property of the extrusion product can be obtained. In this article, the two interim dies were taken as a sample to study the microstructure of typical locations of AZ31 magnesium alloy produced by continuous variable cross-section direct extrusion (CVCDE). The results showed that the grains were refined...
The deformation and fracture behavior of hot-rolled medium manganese lightweight (0.32C-3.85Mn-4.18Al-1.53Si) steel was revealed by an in situ tensile test. Deformed δ-ferrite with plenty of cross-parallel deformation bands during in situ tensile tests provides δ-ferrite of good plasticity and ductility, although it is finally featured by the cleavage fracture. The soft and ductile δ-ferrite and high-volume...
In this study, a new extrusion process, alternate extrusion (AE), is proposed. We evaluated the reliability and superiority of this process in practical applications by conducting a simulation using the finite element method, which confirmed the experimental results. The microstructure characteristics of an AZ31 magnesium alloy produced by conventional extrusion (CE) and AE were investigated by electron...
To improve the thickness uniformity and increase the forming limit of sheets to enhance their overall quality, a magnetorheological fluid (MRF) was injected into the punch cavity to act as the force transfer medium and fulfill the function of flexible pressing during the sheet bulging process. The rheological properties of the MRF were changed under the influence of a magnetic field produced by loading...
The problem of connection between dissimilar sheets is discussed in this article, with a focus on cold-pressing joining as the solution. The embedded deformation connection of 304 stainless steel and 1100 pure aluminum is used as an example. Connection strength gradually decreases with the punch load increasing. To improve the connection strength, a relevant approach is proposed. Compared with the...
Lightweight forming was one of the main ways to achieve energy conservation and emission reduction in advanced manufacturing. However, the cold-pressing process was easier to realize dissimilar sheets joining and could reduce the weight of both the material and the structure; therefore, this process was widely used. Taking aluminum and stainless sheets joining as an example, this study designed three...
To discover the deformation behavior and corresponding mechanism of the typical material under fluid pressure, we proposed a test method for the uniaxial tensile deformation performance of the sheet under fluid pressure and developed a testing device as well as a special fixture. The aluminum and aluminum alloy were tested based on this method, respectively. The results indicate that under the uniaxial...
The traditional connections between dissimilar sheets metals have some drawbacks, such as the connection difficulties, high process requirement, and high cost. As a result of these drawbacks, this article proposes a new method for the connection of dissimilar sheet metals: the cold-pressing connection method. Based on the analyses of the structure and characteristics of the connections, three schemes...
Aluminum alloy complex components with limbs, such as antitorque arms, are difficult to manufacture because of their complicated shapes and high requirements in terms of mechanical properties. To form 7075 aluminum alloy antitorque arms precisely, two forming schemes with different billet shapes were used to simulate the precision forming process and study the metal flow laws using DEFORM™-3D software...
This article presents a study of the deformation mechanisms and failure behavior of punch bonding technology for dissimilar sheet metals. Using theoretical and numerical methods, the simulation of the punch bonding process is presented and the results show that to realize effective punch bonding, the sheets with higher elastic modulus and yield strength should be located at the punch side. It is also...
To improve the poor plasticity of 2024 aluminum alloy sheet, which causes wrinkle and fracture in conventional deep drawing of complexshaped components, hydromechanical deep drawing (HDD) with pre-bulging was investigated. The loading paths of chamber pressure and pre-bulging pressure were designed and optimized by numerical simulations and experiments, and effects of loading paths were obtained and...
In order to discover the deformation mechanism in compression, L-shaped components of aluminum alloy are taken as specimen to investigate the influence of metal flow and deformation behavior in the forming process. Research results show that when the sectional shape is fixed, the range of plastic zone in the deformation body is expanded with the increase of the height of the billet. In addition, the...
To manufacture lightweight tube components for aerospace oil circuit systems, an experiment was run to investigate the deformation characteristics on Y-shaped tube hydroforming of 6061 aluminum alloy. Both strain state and metallurgical structure indicate that there are four kinds of prevailing defects during Y-shaped tube hydroforming: bursting, lack of cylindricity, wrinkling, and thinning due to...
In order to study isothermal forming rules of aerospace aluminum alloy forgings, we have simulated the forming process of different billet shapes, and compared the deformation mechanism and load characteristics. Comparing experimental and theoretical values of both sides of wall thickness shows that the maximum error is only 3.4% meeting the specification requirements.
In order to reveal the mechanism of extrusion forming for large-scale aluminum alloy seamless pipe, in this research the rigid-viscous plastic finite element method was used to analyze the effect of the technological parameters of the aluminum alloy pipe extrusion process, consistent with the use requirements.
To research impeller parts flow behaviors in the die forging process, the finite element method is used to study the deformation flow behavior of different shapes in the blank forming process. The results show that the blade parts of the forgings were hard to fill, but with the section of the blade shifting down, the metal has a marked trend to flow toward this area of the die cavity. Compared with...
For the complex analysis of metal flow behaviors in the plastic bulk forming process, die forging can be divided into basic deformation models. A three-dimensional complex forging was built in which different deformation models were coupled. In this study, the forging process was analyzed during different stages and at different zones, and a rule of metal flowing was obtained in the coupled forming...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.