Formability of Aluminum Alloys During Single Point Incremental Forming (original) (raw)
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Analysis of the metal sheets formability at single point incremental forming process
MATEC Web of Conferences
Although research on incremental forming process began a few decades ago, it is still a process in development phase. Single point incremental forming is a simple process and the deformation of the sheet blank is done with the help of a punch that follows a known toolpath. In the case of this process, one important aspect is the prediction of material failure. To achieve this with the help of a finite element analysis, a series of experiments were performed to determine the forming limit diagram. In this paper, an attempt has been made to determine the forming limit diagram for the AA1050 aluminum alloy. The experiments were performed with the help of an industrial robot, KUKA KR 210-2, thus the part can be measured with an optical measuring instrument obtaining the major and minor strain from forming limit diagram.
Experimental Investigation of Single Point Incremental Sheet Metal Forming of Aluminum 6061
Bulletin of the Faculty of Engineering. Mansoura University
This paper presents an experimental assessment of the factors affecting the Single Point Incremental Forming (SPIF) process aiming to characterize their influence when forming Al 6061 sheets. The experimental trials were undertaken at different levels of incremental depths, feed rates, and spindle speeds and the process responses were the obtainable surface roughness and thinning. The results showed that the incremental depth has a significant effect on the surface roughness and feed rate found to be the second effective parameter. Also, thinning was highly dependent on the applied spindle speed. However, the results revealed that the stretching of the material prominently increased with the increase of feed rate up to a certain limit (1000
Materials
Single Point Incremental Forming (SPIF) is an unconventional forming process that is suitable for prototype production and small lot production due to the economical tooling cost, short lead time, and the ability to create symmetrical and asymmetrical complex geometries without the use of expensive dies. This article presents the effect of the step size Δz of a forming tool made of 145Cr6 tool steel on the formability and maximum forming angle, mechanical properties, hardness, surface roughness, microstructure and texture of bimetallic Al/Cu sheets. Experiments were conducted at a constant rotational speed and feed rate, with the use of rapeseed oil as a lubricant. The tests were carried out with the use of a forming tool on both sides of the bimetallic sheet. The shape and dimensions of the formed elements are determined by non-contact optical 3D scanning. It has been proved that an increase in the step size Δz affects the deterioration of the surface quality of the specimens (an i...
Advances in Science and Technology Research Journal
Single-point incremental forming (SPIF) is a kind of incremental sheet forming that is significantly novel. This method involves the utilization of a computer numerical control (CNC) machine to control the path of a forming tool, which is produced by a computer-aided manufacturing program (CAM), as it stretches a metallic sheet to achieve a desired shape. Low patch output and customized parts are good candidates for this kind of technique. The aim of the present investigation is first to study the effect of Aluminum alloy 6061 strength on the thickness distribution and thinning ratio in SPIF and then select the optimal strength to ensure uniform thickness and minimize the thinning. In order to achieve this, two different strengths of Al 6061 sheets have been employed: One used in its original form and the other heat treated to change its strength. Specimens have been prepared using the SPIF procedure for a truncated cone with dimensions of 120 mm diameter and 40 mm depth; the forming slope is 50°, and Solid work program was used to create the tool path. The thickness reduction along the wall portions was analyzed employing the finite element method using Abaqus software, and the numerical results were experimentally confirmed, where the deviation ratio between simulation and experiment was 3% for sample 1 and 5% for sample 2. The findings manifested that the specimens exhibited a consistent distribution of thickness, and the maximum thinning ratio decreased from 30% to 28.5% as the yield strength decreased from 278 MPa to 68.7 MPa, respectively.
Port-Said Engineering Research Journal, 2017
In this paper, finite-element modeling (FEM) was developed to simulate the incremental sheet metal forming technique. The study mainly focused on the manufacture of complex shapes and modeled using ABAQUS/Explicit finite-element code as a simulation tool. Accordingly, a series of simulation trials have been carried out and the obtained results validated via experimental tests. The results indicated that the increasing of incremental depth increased the deformation force and this causing an increase of the stress. Also, the increase of the incremental depth from 0.5 mm to 1.0 mm increasing the sheet thinning from 0.8 mm to 0.698 mm. Moreover, the increasing of feed rate increased the thinning with the same value for both of FEM and experimental tests. Furthermore, the results showed that the incremental depth has a significant effect on the surface roughness and sheet thickness and that feed rate have found to be the second effective parameter.
Evaluation of strain and stress states in the single point incremental forming process
The International Journal of Advanced Manufacturing Technology, 2015
Single point incremental forming (SPIF) is a promising manufacturing process suitable for small batch production. Furthermore, the material formability is enhanced in comparison with the conventional sheet metal forming processes, resulting from the small plastic zone and the incremental nature. Nevertheless, the further development of the SPIF process requires the full understanding of the material deformation mechanism, which is of great importance for the effective process optimization. In this study, a comprehensive finite element model has been developed to analyse the state of strain and stress in the vicinity of the contact area, where the plastic deformation increases by means of the forming tool action. The numerical model is firstly validated with experimental results from a simple truncated cone of AA7075-O aluminium alloy, namely, the forming force evolution, the final thickness and the plastic strain distributions. In order to evaluate accurately the through-thickness gradients, the blank is modelled with solid finite elements. The small contact area between the forming tool and the sheet produces a negative mean stress under the tool, postponing the ductile fracture occurrence. On the other hand, the residual stresses in both circumferential and meridional directions are positive in the inner skin of the cone and negative in the outer skin. They arise predominantly along the circumferential direction due to the geometrical restrictions in this direction.
Single Point Incremental Forming and the Forming Criteria for AA3003
Single Point Incremental Forming (SPIF) is a modern method of forming sheet metal, where parts can be formed without the use of dedicated dies. The ability of SPIF to form a part is based on various forming parameters. Previous work was not accomplished with the help of design of experiments, thus reducing the number of parameters varied at any time. This paper presents two designs of experiments, which formalise the forming parameters critical in SPIF and the degree to which they affect formability.
Experimental Investigation of Thickness Distribution in Incremental Sheet Forming for Aluminium
—Incremental Sheet Forming (ISF) is gaining a lot of attention due to the ease with which it forms metal sheets to required shape and the capability of the process to form custom made products economically. The material used for the experimentation is Aluminium sheet AA1100 grade. This alloy is commercially pure aluminium with excellent forming characteristics. In this paper effect of four parameters namely Tool size, Spindle speed, Step size and Wall inclination on thickness distribution in ISF process is discussed. The results show that formability in ISF is highly variable with input parameters. It was found that the thickness in mid region of forming depth is less than the thickness at the corners. Further it was evident from results that wall inclination below 20° is not possible with single pass forming in ISF.
Experimentation and FE simulation of single point incremental forming
Materials Today: Proceedings, 2019
One of the emerging flexible forming technologies in the sheet metal engineering is the incremental sheet forming, it uses universal tooling that is mostly part independent. Hence this process provide higher flexibility reducing the product development greatly and making it useful for low volume production. Single Point Incremental forming is drawing attention of the researchers & scientist all over the world because of the attractive characteristics. Like: improved formability, elimination of die & conventional press and ease of operation on general purpose Vertical Machining Centre. As this way of creating sheet metal formed products is in development stage, the factors affecting this needs comprehensive investigations. In this paper experimental and numerical investigation of formability of Aluminium 8011 alloy are presented and compared by preparing a conical frustum shape using SPIF process. The complete process is simulated using CATIA manufacturing simulation model to generate the path of Hemispherical end tool tip. Numeric Control (NC) part program is generated with the help of this simulated path to form the sheet into conical frustum shape on CNC mill machine. Four process parameters viz. vertical step depth, feed rate, spindle speed and angle of cone are chosen for the experimental investigations keeping height of the cone and material sheet thickness constant. Temperature, thickness reduction, strain and machining time are selected as a response variable. Optimizations are performed using TAGUCHI and ANOVA while the numerical study of the process is performed through ANSYS workbench software to predict stress, strain, temperature and thickness Results of experiments and numerical study are in close accord.
Fundamental studies on the incremental sheet metal forming technique
Journal of Materials Processing Technology, 2003
The idea of incremental forming technique has been investigated for production of sheet metal components. With this technique, the forming limit curve (FLC) appears in a different pattern, revealing an enhanced formability, compared to conventional forming techniques. In the present study, the formability of an aluminum sheet under various forming conditions was assessed and difficult-to-form shapes were produced with the technique. By utilizing knowledge and experience obtained during the present study, it became possible to produce some free surfaces.