Effects of Process Parameters on the Thickness Uniformity in Two-Point Incremental Forming (TPIF) with a Positive Die for an Irregular Stepped Part

Incremental sheet forming (ISF) is a novel flexible forming technology with advantages, such as a low forming force, low-energy-consuming equipment, and good forming performance. The lack of available information about the formability of the two-point incremental forming (TPIF) process makes it limited for practical applications. Taking an irregular stepped part as the target part, the effects of process parameters on the thickness uniformity when using TPIF with a positive die for AA1060 aluminum alloy sheets were investigated. First, the set of optimal parameters regarding the diameter of the tool head, feed rate, and the step size were obtained through orthogonal experiments. Furthermore, the optimal parameter set of the number of forming passes, the direction of movement of the forming tool, and the forming angle was determined and the optimal forming result was numerically and experimentally verified. This demonstrated that the parameters affecting the thickness uniformity of the irregular stepped parts were, in descending order, the diameter of the forming tool, the feed rate, and the step size, with corresponding optimal values of 12 mm, 15,000 mm/min, and 0.4 mm, respectively. With an increase of the number of passes and a decrease of the forming angle between adjacent passes, and adopting an alternating clockwise and counterclockwise toolpath, the thickness uniformity of the formed parts was effectively improved.

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STUDY ON FORMING FORCES OF PARTS PROCESSED BY SINGLE POINT INCREMENTAL FORMING WITH DUMMY SHEET

Journal of Manufacturing Engineering ◽

10.37255/jme.v4i3pp120-128 ◽

2019 ◽

Vol 14 (3) ◽

Author(s):

Vikas Sisodia ◽

Shailendra Kumar

Keyword(s):

Process Parameters ◽

Feed Rate ◽

Incremental Forming ◽

Single Point ◽

Sheet Thickness ◽

Single Point Incremental Forming ◽

Forming Force ◽

Step Size ◽

Wall Angle ◽

Influence Of Process Parameters

The present paper describes the experimental investigation on influence of process parameters on maximum forming force in Single Point Incremental Forming (SPIF) process using dummy sheet. Process parameters namely dummy sheet thickness, tool size, step size, wall angle and feed rate are selected. Taguchi L18 orthogonal array is used to design the experiments. From the analysis of variance (ANOVA) dummy sheet thickness, tool size, step size and wall angle are significant process parameters while feed rate is insignificant. It is found that as dummy sheet thickness, tool size, step size and wall angle increase magnitude of peak forming force increases while there is marginal decrease in forming force as feed rate increases. Predictive model is also developed for forming force. Validation tests are performed in order to check the accuracy of developed model. Optimum set of process parameters is also determined to minimize forming force. Experimental results are in good agreement with results predicted by the developed mathematical model.

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Improve the Micro-hardness of Single Point Incremental Forming Product Using Magnetic Abrasive Finishing

Engineering and Technology Journal ◽

10.30684/etj.v38i8a.906 ◽

2020 ◽

Vol 38 (8A) ◽

pp. 1137-1142

Author(s):

Baqer A. Ahmed ◽

Saad K. Shather ◽

Wisam K. Hamdan

Keyword(s):

Vickers Hardness ◽

Feed Rate ◽

Incremental Forming ◽

Single Point ◽

Single Point Incremental Forming ◽

Step Size ◽

Coil Current ◽

Magnetic Abrasive Finishing ◽

Finishing Process ◽

Abrasive Finishing

In this paper the Magnetic Abrasive Finishing (MAF) was utilized after Single Point Incremental Forming (SPIF) process as a combined finishing process. Firstly, the Single Point Incremental forming was form the truncated cone made from low carbon steel (1008-AISI) based on Z-level tool path then the magnetic abrasive finishing process was applied on the surface of the formed product. Box-Behnken design of experiment in Minitab 17 software was used in this study. The influences of different parameters (feed rate, machining step size, coil current and spindle speed) on change in Micro-Vickers hardness were studied. The maximum and minimum change in Micro-Vickers hardness that achieved from all the experiments were (40.4 and 1.1) respectively. The contribution percent of (feed rate, machining step size, coil current and spindle speed) were (7.1, 18.068, 17.376 and 37.894) % respectively. After MAF process all the micro surface cracks that generated on the workpiece surface was completely removed from the surface.

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The Effected of Single Point Incremental Forming Process Parameters on the Formed Part Surface Roughness

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.979.335 ◽

2014 ◽

Vol 979 ◽

pp. 335-338

Author(s):

Kittiphat Rattanachan ◽

Chatchapol Chungchoo

Keyword(s):

Surface Roughness ◽

Sheet Metal ◽

Process Parameters ◽

Feed Rate ◽

Incremental Forming ◽

Single Point ◽

Single Point Incremental Forming ◽

Tool Rotational Speed ◽

Forming Process ◽

Inner Surface

The single point incremental forming process (SPIF) are suited for sheet metal prototyping, because it is a low cost production process that produces sheet metal part without any used of die, and easy to adjust the part’s geometry by change toolpath. But the quality of forming parts is still in doubt. In some applications, such as mould cavity for rapid mould and the medical parts, in this case the inside surface roughness plays an importance role. In this paper, the SPIF process parameters that affected to the inner surface roughness were experimental studied. The investigated parameters are composing of tool feed rate, side overlap, depth step and tool radius. The 2k-p factorial experimental design was used to analyze the interaction between each parameter. The results showed that increasing feed rate and depth step decreased inner surface roughness. Reducing tool rotational speed and feed rate reduced inner surface roughness. So increasing depth step with decreasing side overlap reduced inner surface roughness. The large tool radius and lower side overlap improved inner surface roughness. The large tool radius and higher depth step improved inner surface roughness. And last, reducing tool rotational speed with larger tool radius, the inner surface roughness is decreased.

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Investigation the Effect of Process Variables on the Formability of Parts Processed by Single Point Incremental Forming

Al-Khwarizmi Engineering Journal ◽

10.22153/kej.2018.12.003 ◽

2019 ◽

Vol 14 (2) ◽

pp. 58-70

Author(s):

Adil Shbeeb Jabber

Keyword(s):

Feed Rate ◽

Metal Forming ◽

Single Point ◽

Effective Strain ◽

Image Processing Technique ◽

Cnc Machine ◽

Forming Process ◽

Step Size ◽

Forming Angle ◽

Incremental Step

Incremental sheet metal forming process is an advanced flexible manufacturing process to produce various 3D products without using dedicated tool as in conventional metal forming. There are a lot of process parameters that have effect on this process, studying the effect of some parameters on the strain distributions of the product over the length of deformation is the aim of this study. In order to achieve this goal, three factors (tool forming shape, feed rate and incremental step size) are examined depending on three levels on the strain distributions over the wall of the product. Strain measurement was accomplished by using image processing technique using MATALB program. The significance of the control factors are explored using two statistical methods: analysis of variance (ANOVA) and main effect plot (MEP). All experiments were carried out on a sheet of Aluminum alloy (Al1050) with thickness 0.9 mm by using 3 axes CNC machine to produce frustum pyramid product. The result showed that the feed rate is a parameter that has large effect on the values of the effective strain percentage contribution of (42.86% and 51.42%), respectively, and is followed by step size (25.1% and 30.60%) percentage contributions and finally the tool shape with (21.79% and 10.54%) on the (55° and 45°) wall angle, respectively. The maximum and minimum average effective strain computed on the 55◦ forming angle were (0.580 and 0.399), respectively. Finally, the maximum and minimum average effective strain computed on the 45◦ forming angle were equal to (0.412 and 0.324), respectively.

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Numerical Simulation on the Effect of Process Parameters for Incremental Sheet Forming

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.158 ◽

2010 ◽

Vol 97-101 ◽

pp. 158-161 ◽

Cited By ~ 1

Author(s):

Qin Qin ◽

Di Ping Wu ◽

Mi Li ◽

Yong Zang

Keyword(s):

Process Parameters ◽

Rapid Prototype ◽

Sheet Forming ◽

Incremental Sheet Forming ◽

Layered Manufacturing ◽

Forming Process ◽

Step Size ◽

Flexible Technology ◽

Vertical Step ◽

Forming Angle

Incremental sheet forming (ISF), based on the ‘layered manufacturing’ principle of rapid prototype manufacturing technology, is an innovative and highly flexible technology for forming complex shaped parts without the need for costly dies. This paper presents a numerical investigation on the influence of forming process parameters by modeling the forming process. ANSYS/LS-DYNA has been used for the simulation. The results of study show that small vertical step size can improve the accuracy of the forming. Moreover, large forming angle can increase plastic strain and the four screwdown point optimization paths is an effective method to increase the accuracy of the formed sheet.

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Central Composite Design Optimisation in Single Point Incremental Forming of Truncated Cones from Commercially Pure Titanium Grade 2 Sheet Metals

Materials ◽

10.3390/ma14133634 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3634

Author(s):

Marcin Szpunar ◽

Robert Ostrowski ◽

Tomasz Trzepieciński ◽

Ľuboš Kaščák

Keyword(s):

Surface Roughness ◽

Central Composite Design ◽

Feed Rate ◽

Incremental Forming ◽

Single Point ◽

Pure Titanium ◽

Single Point Incremental Forming ◽

Forming Force ◽

Step Size ◽

Central Composite

Single point incremental forming (SPIF) is an emerging process that is well-known to be suited for fabrication in small series production. The aim of this paper was to determine the optimal input parameters of the process in order to minimise the maximum of both the axial and the in-plane components of the forming force achieved during SPIF and the surface roughness of the internal surface of truncated-cone drawpieces. Grade 2 pure titanium sheets with a thickness of 0.4 mm were used as the test material. The central composite design and response surface method was used to determine the number of experiments required to study the responses through building a second-order quadratic model. Two directions of rotation of the forming tool were also considered. The input parameters were spindle speed, tool feed rate, and step size. The mathematical relations were defined using the response surfaces to predict the surface roughness of the drawpieces and the components of the forming force. It was found that feed rate has an insignificant role in both axial and in-plane forming forces, but step size is a major factor affecting axial and radial forming forces. However, step size directly affects the surface roughness on the inner surfaces of the drawpieces. Overall, the spindle speed −579 rpm (clockwise direction), tool feed 2000 mm/min, and step size 0.5 mm assure a minimisation of both force components and the surface roughness of drawpieces.

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Experimental Investigation and Optimal Prediction of Maximum Forming Angle and Surface Roughness of an Al/SUS Bimetal Sheet in an Incremental Forming Process Using Machine Learning

Materials ◽

10.3390/ma12244150 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4150

Author(s):

Raneen Abd Ali ◽

Wenliang Chen ◽

M.S.H. Al-Furjan ◽

Xia Jin ◽

Ziyu Wang

Keyword(s):

Machine Learning ◽

Surface Roughness ◽

Incremental Forming ◽

Single Point ◽

Continuous Variable ◽

Gradient Boosting ◽

Forming Process ◽

Step Size ◽

Forming Angle ◽

Tool Diameter

Bimetal sheets have superior properties as they combine different materials with different characteristics. Producing bimetal parts using a single-point incremental forming process (SPIF) has increased recently with the development of industrial requirements. Such types of sheets have multiple functions that are not applicable in the case of monolithic sheets. In this study, the correlation between the operating variables, the maximum forming angle, and the surface roughness is established based on the ensemble learning using gradient boosting regression tree (GBRT). In order to obtain the dataset for the machine learning, a series of experiments with continuous variable angle pyramid shape were carried out based on D-Optimal design. This design is created based on numerical variables (i.e., tool diameter, step size, and feed rate) and categorical variable (i.e., layer arrangement). The grid search cross-validation (CV) method was used to determine the optimum GBRT parameters prior to model training. After the parameter tuning and model selection, the model with a better generalization performance is obtained. The reliability of the predictive models is confirmed by the testing samples. Furthermore, the microstructure of the aluminum/stainless steel (Al/SUS) bimetal sheet is analyzed under different levels of operating parameters and layer arrangements. The microstructure results reveal that severe cracks are attained in the case of a small tool diameter while a clear refinement is observed when a high tool diameter value with small step down is used for both Al and SUS layers.

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Study of Friction and Wear Effects in Aluminum Parts Manufactured via Single Point Incremental Forming Process Using Petroleum and Vegetable Oil-Based Lubricants

Materials ◽

10.3390/ma14143973 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3973

Author(s):

José M. Diabb Zavala ◽

Oscar Martínez-Romero ◽

Alex Elías-Zúñiga ◽

Héctor Manuel Leija Gutiérrez ◽

Alejandro Estrada-de la Vega ◽

...

Keyword(s):

Surface Roughness ◽

Process Parameters ◽

Friction And Wear ◽

Incremental Forming ◽

Single Point ◽

Single Point Incremental Forming ◽

Forming Process ◽

Step Size ◽

Vertical Step ◽

Stribeck Curves

This paper focuses on studying how mineral oil, sunflower, soybean, and corn lubricants influence friction and wear effects during the manufacturing of aluminum parts via the single point incremental forming (SPIF) process. To identify how friction, surface roughness, and wear change during the SPIF of aluminum parts, Stribeck curves were plotted as a function of the SPIF process parameters such as vertical step size, wall angle, and tool tip semi-spherical diameter. Furthermore, lubricant effects on the surface of the formed parts are examined by energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) images, the Alicona optical 3D measurement system, and Fourier-transform infrared spectroscopy (FTIR). Results show that during the SPIF process of the metallic specimens, soybean and corn oils attained the highest friction, along forces, roughness, and wear values. Based on the surface roughness measurements, it can be observed that soybean oil produces the worst surface roughness finish in the direction perpendicular to the tool passes (Ra =1.45 μm) considering a vertical step size of 0.25 mm with a 5 mm tool tip diameter. These findings are confirmed through plotting SPIFed Stribeck curves for the soybean and corn oils that show small hydrodynamic span regime changes for an increasing sample step-size forming process. This article elucidates the effects caused by mineral and vegetable oils on the surface of aluminum parts produced as a function of Single Point Incremental Sheet Forming process parameters.

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Effect of hardening law and process parameters on finite element simulation of single point incremental forming (SPIF) of 7075 aluminum alloy sheet

Mechanics & Industry ◽

10.1051/meca/2020019 ◽

2020 ◽

Vol 21 (3) ◽

pp. 302 ◽

Cited By ~ 1

Author(s):

Rasoul Esmaeilpour ◽

Hyunki Kim ◽

Taejoon Park ◽

Farhang Pourboghrat ◽

Akshat Agha ◽

...

Keyword(s):

Process Parameters ◽

Strain Distribution ◽

Incremental Forming ◽

Single Point ◽

Single Point Incremental Forming ◽

Effective Plastic Strain ◽

Step Size ◽

Hardening Law ◽

Element Simulation ◽

Tool Force

In the last two decades, the advances of using computers in sheet metal forming processes have introduced a novel adjustable process known as incremental sheet forming (ISF) as an optimal method for fast prototyping and low numbers of production. Formability and deformation behavior of ISF process are highly affected by the selected process parameters, such as the toolpath, step size, tool diameter, feed rate, and lubrication. The purpose of this work was to study the effect of these process parameters as well as hardening law on single point incremental forming (SPIF) process. For this work, a truncated-cone geometry was considered as a target shape with 7075-O aluminum alloy sheets. The simulations were conducted with different process parameters, i.e., toolpath type, step size, tool size, feed rate, friction coefficient, and wall angle with respect to the tool force and moment, effective plastic strain distribution and thickness of the part. In addition, three types of hardening laws i.e., isotropic extended Voce type hardening law, combined isotropic-kinematic Chaboche type hardening laws with single and double back-stress terms were applied in the finite element simulation of SPIF process. A detailed comparison of these hardening laws' predictions was made with respect to the tool force and moment, effective plastic strain distribution and thickness of the part.

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Force Measurements for Single Point Incremental Forming: An Experimental Study

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.6-8.441 ◽

2005 ◽

Vol 6-8 ◽

pp. 441-448 ◽

Cited By ~ 21

Author(s):

Joost R. Duflou ◽

Alexander Szekeres ◽

P. Vanherck

Keyword(s):

Process Parameters ◽

Incremental Forming ◽

Single Point ◽

Force Measurements ◽

Test Program ◽

Forming Process ◽

Step Size ◽

Experimental Platform ◽

Vertical Step ◽

The Relationship

In this paper an experimental platform capable of measuring forces in process during an incremental forming procedure is described and the results garnered from it are presented. Some of the earliest measurements of forces in incremental forming and the changes induced on the measured load are reported. Using a table type force dynamometer with incremental forming fixture mounted on top, three components of force were measured throughout the forming process. They were found to vary as the parts were made. The reported experimental test program was focused on the influence of three different process parameters on the forming forces: the vertical step size between consecutive contours, the diameter of the tool and the steepness of the part’s wall. For the tested material, analytical results demonstrating the relationship between the respective process parameters and the induced forces are presented in this paper.

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