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Cryorolling of Aluminum Alloy Sheets and Their Characterization: A Review
Published in Kakandikar Ganesh Marotrao, Anupam Agrawal, D. Ravi Kumar, Metal Forming Processes, 2023
Kandarp Changela, K. Hariharan, D. Ravi Kumar
Hydroforming is one of the promising advanced sheet metal forming techniques that can be used in automobile and aerospace industries. In this technique, high pressure fluid is used to form sheet metal parts within die cavity. There are many advantages of hydroforming compared to conventional forming such as easy to form complex parts, uniform strain distribution and good surface quality. Recently, Feyissa and Ravi Kumar [82] investigated hydroforming of cryorolled AA 5083 sheets for the first time. They studied deep drawing of flat bottom square cup-shaped parts by hydroforming of cryorolled AA 5083 sheets annealed at 275°C for 15 minutes and compared with the conventional deep drawing process (Figure 5.20 (a)). It was demonstrated that the formability of cryorolled Al alloy sheets can be enhanced by hydroforming due to lower thinning and more uniform strain distribution compared to the conventional deep drawing process. The study demonstrated that combining two unconventional forming techniques, cryorolling with hydroforming, is a potential route to produce complex sheet metal parts from high strength Al alloy sheets. In this study, process window was also determined to successful drawing of square cup by hydroforming from cryorolled aluminium alloy sheet blanks. Using different combination of process parameters and large experimental data from hydroforming process, process window was divided into four regions, as shown in Figure 5.20 (b).
Aluminum-Manufacturing Methods
Published in Raghu Echempati, Primer on Automotive Lightweighting Technologies, 2021
Hydroforming is one of the sheet- or tube-forming processes where the material positioned inside the mold is filled with liquid water or air, and very high pressure is given from both ends of the material in order to deform the material as the mold moves. Tube hydroforming is generally defined as high or low pressure with the demarcation point of around 83MPa. There are two main types of hydroforming: tube hydroforming and sheet hydroforming. Tube hydroforming is used when a complex cross section shape is needed. In tube hydroforming, a section of cold rolled steel or aluminum tubing is placed in a closed die set where a pressurized fluid is forced into the ends of the tube and the tube reshapes within the confines of the mold. Figure 4.29 shows the working principle of tube-hydroforming simulation using AutoForm [24]. The figure shows the four steps of the process. Figure 4.30 shows a sheet that can be formed by exerting fluid pressure into the die cavity [25, 26]. Figure 4.30 shows the initial step (top die in the open position), and the final step after the sheet is formed by water or air under pressure (with the top die in closed position). This process produces better-quality drawn parts compared to mechanical stamping, for example.
Vehicle structure and aerodynamics
Published in M.J. Nunney, Light and Heavy Vehicle Technology, 2007
Front and rear subframes were traditionally fabricated from several steel stampings welded together and locally reinforced. Since Ford of America introduced a ‘hydroformed’ front subframe in the mid-1990s, this method of manufacture is now widely used as indeed it is for various other automotive components. Hydroforming or tubular hydroforming is basically a process in which a tube is inserted in the closed cavity of a die, which is formed to correspond to the shape of the finished component. The tube is then partially sealed and filled under high pressure with a hydraulic fluid, so that the increasing pressure forces the tube to assume the internal shape of the die. Manufacturing advantages of hydroforming include more economic assembly arising from fewer parts, the absence of welded flanges and hence a saving in weight, and from a design point of view the ability to accommodate changes in cross-section area. An alternative to the steel subframe is one fabricated from aluminium alloy, using for example extruded sections as introduced in 1999 by General Motors for their Chevrolet Impala, or hydroformed tubing that has recently featured in German practice. An aluminium alloy subframe can be advantageous in terms of high rigidity and low weight.
Numerical and experimental predictions of formability parameters in tube hydroforming process
Published in Australian Journal of Mechanical Engineering, 2023
Bapurao G. Marlapalle, Rahulkumar S. Hingole
(Omar, Tewari, and Narasimhan 2015) studied that the strain path for weld as well as base metal during tube bulging. The hydroforming process has advantages over stamping and welding conventional technology such as parts consolidation, weight reduction through more efficient section design and tailoring of the wall thickness in structural components etc. Also, observed improvement in structural strength and stiffness through optimised section geometry, lower tooling cost due to fewer parts, fewer secondary operations, tight dimensional tolerances, low spring-back and reduced scrap. Automotive applications observed in exhaust parts, camshafts, radiator frames, front and rear axles, engine cradles, crankshafts, seat frames, and space frames (Ahmetoglu and Altan 2000). The performance of tube hydroforming process is highly dependent on process parameters such as internal pressure, axial feeding, friction, etc. without any type of defects. Therefore, the forming parameters must be determined carefully (Aydemir et al. 2005). Now a day the tube hydroforming process is rapidly implemented in many industrial applications for bulging of tube in desired die cavity. The advantages over the conventional methods are higher strength to weight ratio and lower price. The applications in automotive and aerospace industries such as engine cradle, chassis components, seat frames, exhaust manifolds, structural body and power transmission components, T, X and Y fittings manufacturing (Hartl 2005; Lan et al. 2004b).
Sheet metal shrink flanging process: a critical review of current scenario and future prospects
Published in Materials and Manufacturing Processes, 2023
Again with the help of conventional die and tools system, the concept of hydro-forming is introduced in the flanging process. There are majorly two types of hydro-forming which is utilized in production of flange parts, i.e., rubber bladder hydro-forming, and the other one is fluid forming. Rubber bladder forming is initial version of hydro-forming which utilizes the pressure of fluids through a rubber bladder to be utilized in flanging process [45,239,249,250]. Figure 10 shows the schematic representation of rubber bladder hydro-forming process [45,239,249,250]. In this process a rubber bladder is placed between the fluid and blank. Chances of leakages of fluid are reduced by using such type of rubber bladder hydro-forming [45,239,249,250]. Sheet metal blank is formed by the combined pressure exerted by punch as well as fluid pressure [26,27,30–45,45–83,83–193,193–235,235–239,246–276]. It is a relatively costly procedure as well as utilizes harmful fluids to environment [45,239,249,250].
Study on conveying force area of cone-shaped parts in multi-pass hydroforming
Published in Journal of the Chinese Institute of Engineers, 2020
The fairing is a deep cone-shaped, thin-walled rotary part, which has a maximum diameter D 297 mm, minimum diameter D 67 mm, and depth H 174 mm. It is the shape of fairing (see Figure 1), the material of the sheet is 2A12-O, and the thickness is 1.2 mm. The material properties are shown in Table 1. The maximum of D0/d1 is the limiting drawing ratio (where D0 is the original sheet diameter, d1 is the summation of bottom diameter and fillet radius) when the suspended region does not have wrinkling or rupture. The D0 is 440 mm, and the limit drawing ratio is 4.06 considering the machining allowance. Regardless of the thinning during drawing process, the degree of deformation is large, so it is difficult to form. It requires 7 steps by the conventional deep drawing to produce, and the surface quality of the parts is not satisfying. There are the following problems, such as low accuracies, long manufacturing cycles, and low production efficiency, so hydroforming technology is indicated as useful for improving the forming limit, the forming quality, reducing forming steps, and improving production efficiency.