Search results for "Forming processes"
showing 10 items of 73 documents
Beta forging of Ti-6Al-4V: Microstructure evolution and mechanical properties
2013
Titanium alloys are finding an increasing use in the aeronautical field, due to their characteristics of high mechanical properties, lightness and corrosion resistance. Moreover these alloys are compatible with the carbon fibre reinforced plastics that are also finding a wide use in the aeronautical field. On the other hand the use of these alloys implies some drawbacks, for example titanium alloys are often considered more difficult to form and generally have less predictable forming characteristics than other metallic alloys such as steel and aluminum. In this paper was studied both the microstructure evolution and the mechanical properties of a Ti-6Al-4V rolled bar after hot forging. The…
Sheet metal forming of titanium blanks using flexible media
1998
Abstract Sheet metal forming processes using flexible media are increasingly utilized in the industrial practice due to the relatively low tooling cost. In the present investigation, a rubber forming process is applied to the manufacturing cycle of a titanium alloy component for acoustic tweeters. The proposed process allows a reduction in manufacturing costs and production time since it permits the elimination of some joining operations. The FEM analysis has permitted the definition of the optimal process parameters and tooling geometry. Accordingly, several components have been produced; the achieved quality level is comparable with the one obtained utilizing the conventional technology a…
Analysis of Material Formability in Incremental Forming
2002
Abstract Incremental forming is an innovative sheet metal forming technology in which a blank is plastically deformed through the progressive action of a small-size punch, whose movement is governed by a CNC machine. In this way the tool locally deforms the material through an almost pure stretching deformation mechanics. The paper is focused on material formability in incremental forming. Several tests were developed, aimed to the achievement of different straining conditions in the material and consequently to the determination of Forming Limit Diagrams for progressive forming operations. The features and the application of such FLD are discussed in the paper.
Scalable manufacturing of fibrous nanocomposites for multifunctional liquid sensing
2021
This research is supported by the Advanced Manufacturing Program (No. 1927623) from the National Science Foundation and by the McIntire-Stennis Cooperative Forestry Research Program (No. 1020630) from the USDA National Institute of Food and Agriculture. The authors also thank WestRock Paper Company for donated the wood pulp used in this research. Open access funding is enabled and organized by CERN. Cellulose-based paper electronics is an attractive technology to meet the growing demands for naturally abundant, biocompatible, biodegradable, flexible, inexpensive, lightweight and highly miniaturizable sensory materials. The price reduction of industrial carbon nanotube (CNT) grades offers op…
A depth dependent analytical approach to determine material breaking in SPIF
2007
Formability is a relevant issue in Single Point Incremental Forming (SPIF) process since it is one of the main point of strength together to the possibility to avoid any dedicated die. Several researches agree that, depending on working material and process parameters, in SPIF operations there is a threshold slope of the wall that cannot be overcame without material breaking. If deep Incremental Forming is taken into account, despite the previous statement it is possible to demonstrate that, when the threshold angle is imposed, there is a relation between the actual workpiece depth and the material breaking approaching. In this paper, the latter relationship was investigated and formally de…
A New Numerical Method for Axisymmetrical Forming Processes
1987
Summary In this paper a numerical method for the analysis of axisymmetrical forming processes is proposed. This method represents the last development of a previous one which allows to solve forming problems in plane strain condition. The proposed model is baaed on the finite element discretization and on the linearization of the yield surface which leads to solve a LP problem. Two different examples of application, concerning the upsetting of a cylinder and of a hollow disk are reported.
Moving Least Squares Innovative Strategies For Sheet Forming Design
2011
In the last years a great interest in optimization algorithms aimed to design forming processes was demonstrated by many researches. Proper design methodologies to reduce times and costs have to be developed mostly based on computer aided procedures. Response surface methods (RSM) proved their effectiveness in the recent years also for the application in sheet metal forming aiming to reduce the number of numerical simulations. Actually, the main drawback of such method is the number of direct problem to be solved in order to reach good function approximations. A very interesting aspect in RSM application regards the possibility to build response surfaces basing on moving least squares appro…
A contribution on the optimization strategies based on moving least squares approximation for sheet metal forming design
2012
Computer-aided procedures to design and optimize forming processes are, nowadays, crucial research topics since industrial interest in costs and times reduction is always increasing. Many researchers have faced this research challenge with various approaches. Response surface methods (RSM) are probably the most known approaches since they proved their effectiveness in the recent years. With a peculiar attention to sheet metal forming process design, RSM should offer the possibility to reduce the number of numerical simulations which in many cases means to reduce design times and complexity. Actually, the number of direct problems (FEM simulations) to be solved in order to reach good functio…
Forming Processes Design Oriented to Prevent Ductile Fractures
1996
During cold forming processes ductile fractures are sometimes encountered, depending on the operating parameters and on the material properties and determining the production of defective components to be discarded; for this reason the development of a general approach for the prediction of this type of defects is particularly suitable and this aim has been pursued by a large number of researchers in the last two decades. In the paper the most important and diffused models are described and analysed in order to outline the advantages offered by each of them. Some applications to typical metal forming processes are presented, carrying out a comparison between the numerical predictions and th…
Process parameters calibration in 3D tube hydroforming processes
2007
In tube hydroforming the concurrent actions of pressurized fluid and mechanical feeding allow to obtain tube shapes characterized by complex geometries such as different diameters sections and/or bulged zones. What is crucial in such processes is the proper design of operative parameters aimed to avoid defects (for instance shape defects or ductile fractures). The main process parameters are material feeding history (i.e. the punches velocity history) and internal pressure path during the process. In more complex three dimensional processes, also the action of a counterpunch is generally useful to reduce thinning in particular in expansion zones of the tube (i.e. T or Y shaped tubes). The g…