scholarly journals A Comparative Investigation of Conventional and Hammering-Assisted Incremental Sheet Forming Processes for AA1050 H14 Sheets

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1862
Author(s):  
Harshal Y. Shahare ◽  
Abhay Kumar Dubey ◽  
Pavan Kumar ◽  
Hailiang Yu ◽  
Alexander Pesin ◽  
...  
Keyword(s):  
Surface Finish ◽  
Shot Peening ◽  
Numerical Models ◽  
Local Deformation ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Grain Structure ◽  
Experimental Investigations ◽  
Wall Angle ◽  
Truncated Cone

Incremental Sheet Forming (ISF) is emerging as one of the popular dieless forming processes for the small-sized batch production of sheet metal components. However, the parts formed by the ISF process suffer from poor surface finish, geometric inaccuracy, and non-uniform thinning, which leads to poor part characteristics. Hammering, on the other hand, plays an important role in relieving residual stresses, and thus enhances the material properties through a change in grain structure. A few studies based on shot peening, one of the types of hammering operation, revealed that shot peening can produce nanostructure surfaces with different characteristics. This paper introduces a novel process, named the Incremental Sheet Hammering (ISH) process, i.e., integration of incremental sheet forming (ISF) process and hammering to improve the efficacy of the ISF process. Controlled hammering in the ISF process causes an alternating motion at the tool-sheet interface in the local deformation zone. This motion leads to enhanced material flow and subsequent improvement in the surface finish. Typical toolpath strategies are incorporated to impart the tool movement. The mechanics of the process is further explored through explicit-dynamic numerical models and experimental investigations on 1 mm thick AA1050 sheets. The varying wall angle truncated cone (VWATC) and constant wall angle truncated cone (CWATC) test geometries are identified to compare the ISF and ISH processes. The results indicate that the formability is improved in terms of wall angle, forming depth and forming limits. Further, ISF and ISH processes are compared based on the numerical and experimental results. The indicative statistical analysis is performed which shows that the ISH process would lead to an overall 10.99% improvement in the quality of the parts primarily in the surface finish and forming forces.

Effect of Tool Shape on Surface Finish of Components Formed Through Incremental Sheet Forming Process

2015 ◽  
Author(s):  
Pavan Kumar ◽  
Satwik Priyadarshi ◽  
J. J. Roy ◽  
M. K. Samal ◽  
P. K. Jain ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Finish ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Experimental Investigations ◽  
Tool Geometry ◽  
Forming Process ◽  
Tool Geometries ◽  
Tool Shape ◽  
Experimental Approaches

This work explores the effect of tool geometry on surface finish in incremental sheet forming (ISF) process. In the present work, two different tool geometries i.e. hemispherical shaped tool and ellipsoidal shaped tool are considered. Area at tool-sheet contact and scallop height were calculated for both the tool geometries. To assess the effect of tool geometry on the surface finish of the formed components, both analytical and experimental approaches have been used. A test geometry having the shape of frustum of pyramid was considered for the proposed investigation and four surface roughness parameters i.e. arithmetic mean surface roughness (Ra), root mean square surface roughness (Rq), maximum peak-to-valley height (Rt) and average peak-to-valley height (Rz) have been selected as response parameters. Based on the analytical model and experimental investigations, both qualitative and quantitative comparisons had been made among the effects of hemispherical and ellipsoidal tool geometries on surface finish. The investigation deduces that better surface finish of the formed component can be achieved by using ellipsoidal shaped tool rather than the hemispherical shaped tool.

Parameter optimization and texture evolution in single point incremental sheet forming process

2019 ◽  
Vol 234 (1-2) ◽  
pp. 126-139 ◽  
Author(s):  
Shamik Basak ◽  
K Sajun Prasad ◽  
Amarjeet Mehto ◽  
Joy Bagchi ◽  
Y Shiva Ganesh ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Regression Models ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Single Point Incremental Forming ◽  
Input Process ◽  
Truncated Cone

Prototyping through incremental sheet forming is emerging as a latest trend in the manufacturing industries for fabricating personalized components according to customer requirement. In this study, a laboratory scale single-point incremental forming test setup was designed and fabricated to deform AA6061 sheet metal plastically. In addition, response surface methodology with Box–Behnken design technique was used to establish different regression models correlating input process parameters with mechanical responses such as angle of failure, part depth per unit time and surface roughness. Correspondingly, the regression models were implemented to optimize the input process parameters, and the predicted responses were successfully validated at the optimal conditions. It was observed that the predicted absolute error for angle of failure, part depth per unit time and surface roughness responses was approximately 0.9%, 4.4% and 6.3%, respectively, for the optimum parametric combination. Furthermore, the post-deformation responses from an optimized single point incremental forming truncated cone were correlated with microstructural evolution. It was observed that the peak hardness and highest areal surface roughness of 158 ± 9 HV and 1.943 μm, respectively, were found near to the pole of single-point incremental forming truncated cone, and the highest major plastic strain at this region was 0.80. During incremental forming, a significant increase in microhardness occurred due to grain refinement, whereas a substantial increase in the Brass and S texture component was responsible for the increase in the surface roughness.

Brass 70/30 and Incremental Sheet Forming Process

2013 ◽  
Vol 554-557 ◽  
pp. 1419-1431 ◽  
Author(s):  
Daniel Fritzen ◽  
Anderson Daleffe ◽  
Jovani Castelan ◽  
Lirio Schaeffer
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Cnc Machining ◽  
Forming Process ◽  
Wall Angle ◽  
Machining Center ◽  
Cad Cam ◽  
Cnc Machining Center

This work addresses through bibliographies and experiments the behavior of sheet brass 70/30 for Incremental Sheet Forming process - ISF, based on the parameters: wall angle (), step vertical (ΔZ) strategy and the way the tool. Experiments based on the method called Single Point Incremental Forming - SPIF. For execution of practical tests, we used the resources: software CAD / CAM, CNC machining center with three axles, matrix incremental, incremental forming tool and a device press sheets. Furthermore, measurement was made of the true deformation () and thickness (s1). Practical tests have shown that the spiral machining strategy yielded a greater wall angle, compared to the conventional strategy outline.

A Novel Electromagnetic Fixture for Incremental Sheet Metal Forming

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Harish K. Nirala ◽  
Anupam Agrawal
Keyword(s):  
Single Point ◽  
Vital Role ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Experimental Investigations ◽  
Slow Process ◽  
Incremental Sheet Metal Forming ◽  
Set Up ◽  
Localized Plastic Deformation ◽  
Process Speed

Single-point incremental sheet forming (SPISF) is a promising die-less forming technique. It has a variety of applications in many industries, viz., automobile, aerospace, and bone transplants. In SPISF, a sheet of metal is deformed by using numerically controlled single-point, hemispherical end-shaped forming tool, which incrementally deforms the sheet with highly localized plastic deformation. SPISF is a flexible yet relatively slow process when compared with conventional forming techniques like deep drawing and spinning. Since the beginning of die-less forming technology, researchers are recommending it for small batch production system or for customized fabrication. Being a slow process, it still has not achieved wide industrial acceptability. Among several key parameters dictating the process speed, the sheet clamping mechanism is one of the significant parameters of SPISF. Clamping mechanism plays a vital role in its manufacturing lead time. However, research efforts in this direction have been largely neglected. In this investigation, to improve the process speed, a novel electromagnetic clamping mechanism for SPISF is proposed. Detailed numerical and experimental investigations have been carried out to set up its applicability for the SPISF process. From the available literature, it has been found that this type of clamping mechanism in SPISF has not been studied or investigated. The proposed electromagnetic clamping makes the process of sheet clamping faster and convenient, and provides one-click clamping solution. This concept can take the process of incremental sheet forming toward better industrial acceptability. Furthermore, SPISF of symmetric and asymmetric components is conducted to test the feasibility of the concept.

Experimental Investigations and Numerical Analysis for Improving Knowledge of Incremental Sheet Forming Process for Sheet Metal Parts

2009 ◽  
Vol 623 ◽  
pp. 37-48 ◽  
Author(s):  
Steeve Dejardin ◽  
Jean Claude Gelin ◽  
Sebastien Thibaud
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Single Point ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Experimental Investigations ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Forming Strategy ◽  
Set Up

The paper is related to the analysis of shape distortions and springback effects arising in Single Point Incremental Forming. An experimental set up has been designed and manufactured to carry single point incremental forming on small size sheet metal parts. The experimental set up is mounted on 3-axes CNC milling machine tool and the forming tool is attached and move with the spindle. Experiments have been carried out on sheet metal parts to obtain tronconical shapes. The forming strategy associated to the movement of the forming tool has been also investigated. The experiments indicate that shape distortions arising in the corners of the tronconical shape are clearly related to forming strategy. The springback of rings cut in the tronconical parts have been also investigated. It is shown that positive or negative springback could be also related to forming strategy. In order to enhance experimental investigations, Finite Element simulations of the incremental sheet forming have been performed. Results obtained from the simulations prove that if boundary conditions and forming strategy carefully are taking into account, the finite elements results are in good agreement with experiments. So it is then possible to use FEM as a design tool for incremental sheet forming.

Tool Directionality in Contour-Based Incremental Sheet Forming: an Experimental Study on Product Properties and Formability

2011 ◽  
Vol 473 ◽  
pp. 897-904 ◽  
Author(s):  
Philip Eyckens ◽  
Hans Vanhove ◽  
Albert Van Bael ◽  
Joost R. Duflou ◽  
Paul van Houtte
Keyword(s):  
Mechanical Properties ◽  
Tool Path ◽  
Thickness Distribution ◽  
Low Carbon Steel ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Movement Direction ◽  
Low Carbon ◽  
Wall Angle ◽  
Product Thickness

The Incremental Sheet Forming (ISF) process offers a large variety in tool path strategies to obtain a particular final product shape. As fundamental understanding of the relevant deformation modes in ISF is growing, the selection of the tool path strategy may be shifted from trial-and-error towards more fundamentally based knowledge of the process characteristics. Truncated cones and pyramids have been fabricated by both unidirectional (UD) and bidirectional (BD) contour-based tool path strategies, considering different wall angles and materials (Mn-Fe alloyed aluminum sheet and low carbon steel sheet). It is shown that the induced through-thickness shear along the tool movement direction is clearly non-zero for UD, in which case the sense of tool movement is the same for all contours, while it is close to 0 for BD, due to the alternating tool sense during consecutive contours. Furthermore, the heterogeneity in product thickness, as observed for the UD strategy in [1,2], is avoided by using the BD strategy. It is verified that this difference in deformation may affect the mechanical properties in the walls of pyramids by means of tensile testing, but the results are material-dependent. For the aluminum alloy, the re-yield stress along the tool movement direction is smaller for BD in comparison to UD, and the fracture strain in large wall angle products is higher. For the steel, no statistically significant differences in mechanical properties between UD- and BD-processed parts are observed. Finally, for both materials a (slightly) higher limiting wall angle has been repeatedly measured using the BD tool strategy. In light of these results, the bidirectional tool path strategy is to be preferred over the unidirectional one, as thickness distribution and formability are more favorable, while both strategies require similar resources and processing time.

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