scholarly journals A Novel Machine-Learning-Based Procedure to Determine the Surface Finish Quality of Titanium Alloy Parts Obtained by Heat Assisted Single Point Incremental Forming

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1287
Author(s):  
Fernando Bautista-Monsalve ◽  
Francisco García-Sevilla ◽  
Valentín Miguel ◽  
Jesús Naranjo ◽  
María Carmen Manjabacas

Single point incremental forming (SPIF) is a cheap and flexible sheet metal forming process for rapid manufacturing of complex geometries. Additionally, it is important for engineers to measure the surface finish of work pieces to assess their quality and performance. In this paper, a predictive model based on machine learning and computer vision was developed to estimate arithmetic mean surface roughness (Ra) and maximum peak to valley height (Rz) of Ti6Al4V parts obtained by SPIF. An image database was prepared to train different classification algorithms in accordance with a supervised learning approach. A speeded up robust feature (SURF) detector was used to obtain visual vocabulary so that the classifiers are able to group the photographs into classes. The experimental results indicated that the proposed predictive method shows great potential to determine the surface quality, as classifiers based on a support vector machine with a polynomial kernel are suitable for this purpose.

2021 ◽  
Vol 343 ◽  
pp. 04007
Author(s):  
Mihai Popp ◽  
Gabriela Rusu ◽  
Sever-Gabriel Racz ◽  
Valentin Oleksik

Single point incremental forming is one of the most intensely researched die-less manufacturing process. This process implies the usage of a CNC equipment or a serial robot which deforms a sheet metal with the help of a relatively simple tool that follows an imposed toolpath. As every cold metal forming process, besides the many given advantages it has also some drawbacks. One big drawback in comparison with other cold metal forming processes is the low accuracy of the deformed parts. The aim of this research is to investigate the sheet metal bending mechanism through finite element method analysis. The results shows that the shape of the retaining rings has a big influence over the final geometrical accuracy of the parts manufactured through single point incremental forming.


2010 ◽  
Vol 129-131 ◽  
pp. 1222-1227 ◽  
Author(s):  
Ghulam Hussain ◽  
Gao Lin ◽  
Nasir Hayat ◽  
Asif Iqbal

Single Point Incremental Forming (SPIF) is a novel sheet metal forming process. The formability (i.e. spif-ability) in this process is determined through Varying Wall Angle Conical Frustum (VWACF) test. In this paper, the effect of variation in the curvature radius, a geometrical parameter of test, on the test results is investigated. A series of VWACF tests with a variety of curvature radii is performed to quantify the said effect. It is found that the spif-ability increases with increasing of curvature radius. However, any variation in the curvature radius does not affect the spif-ability when the normalized curvature radius (i.e. curvature radius/tool radius) becomes higher than 9.


2014 ◽  
Vol 979 ◽  
pp. 351-354
Author(s):  
Nuttaphong Sornsuwit ◽  
Sunthorn Sittisakuljaroen

The single point incremental forming (SPIF) is a sheet metal forming process with high flexibility on manufacture of each individual workpiece. However, it usually requires more processing time than a conventional forming method and is important to process with appropriate parameters. This study is to investigate the influence of different temperatures on continuing secondary forming of Ti Gr2 sheet, employed the stress relieving and annealing temperature after primary forming. The deformed parts were examined on the following criteria; internal contact surface roughness, microhardness and sectional microstructure. Stress relieving and annealing temperatures of 580°C and 780°C were applied to the formed parts prior to their secondary forming. It is found that the surface roughness increased from Ra 2.104 μm and 2.498 μm to Ra 2.55 μm and 3.18 μm respectively after secondary forming. The formability of 25 mm radius test specimens remained at 12 mm depth with limited obvious change.


2011 ◽  
Vol 12 (3) ◽  
Author(s):  
Meftah Hrairi ◽  
Salah B. M. Echrif

Single Point Incremental Forming (SPIF) is a promising sheet-metal-forming process that permits the manufacturing of small to medium-sized batches of complex parts at low cost. It allows metal forming to work in the critical ‘necking-to-tearing' zone which results in a strong thinning before failure if the process is well designed. Moreover, the process is complex due to the number of variables involved. Thus, it is not possible to consider that the process has been well assessed; several remaining aspects need to be clarified. The objective of the present paper is to study some of these aspects, namely, the phenomenon of the wall thickness overstretch along depth and the effect of the tool path on the distribution of the wall thickness using finite element simulations.Abstrak: Pembentukan Tokokan Mata Tunggal (Single Point Incremental Forming (SPIF)) merupakan satu proses pembentukan kepingan logam yang membolehkan pembuatan dalam jumlah yang kecil hingga sederhana, bahagian-bahagian yang kompleks pada kos yang rendah. Jika proses ini direka dengan baik, kaedah ini membolehkan pembentukan logam yang baik terhasil. Jika tidak, semasa peringkat zon kritikal ‘perleheran-ke-pengoyakan' menyebabkan penipisan keterlaluan yang boleh menyebabkan logam tersebut rosak. Tambahan pula, proses ini agak kompleks, kerana ia melibatkan beberapa pemboleh ubah. Maka, walaupun proses ini telah dinilaikan seeloknya; masih terdapat beberapa aspek lain yang perlu diperjelaskan. Objektif kertas ini dibentangkan adalah untuk mengkaji beberapa aspek tertentu, seperti, ketebalan dinding regangan berlebihan di sepanjang kedalaman dan kesan tool path (beberapa siri posisi koordinat untuk menentukan pergerakan alatan memotong ketika operasi memesin) terhadap pengagihan ketebalan dinding menggunakan simulasi unsur terhingga.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7641
Author(s):  
Jesús Andrés Naranjo ◽  
Valentín Miguel ◽  
Juana Coello ◽  
María Carmen Manjabacas ◽  
Alberto Martínez-Martínez ◽  
...  

Heat-assisted single point incremental forming or HA-SPIF has a great potential for producing one-piece batches of hard-to-form materials such as Ti6Al4V alloy for medical and aeronautical applications. One of the limitations of the process is the difficulty in achieving a reasonable surface finish, which makes essential the characterization of the tribological process in the tool–sheet contact. In fact, not much work can be found at this point in literature. In this research, a novel procedure for evaluating the adhesion on the tool surface is proposed and the influence of the temperature is determined. The surface finish of parts is analyzed, and the changes promoted by HA-SPIF appearing in the morphology of the external surface layer are characterized by SEM.


2021 ◽  
Vol 883 ◽  
pp. 217-224
Author(s):  
Yannick Carette ◽  
Marthe Vanhulst ◽  
Joost R. Duflou

Despite years of supporting research, commercial use of the Single Point Incremental Forming process remains very limited. The promised flexibility and lack of specific tooling is contradicted by its highly complex deformation mechanics, resulting in a process that is easy to implement but where workpiece accuracy is very difficult to control. This paper looks at geometry compensation as a viable control strategy to increase the accuracy of produced workpieces. The input geometry of the process can be compensated using knowledge about the deformations occurring during production. The deviations between the nominal CAD geometry and the actual produced geometry can be calculated in a variety of different ways, thus directly influencing the compensation. Two different alignment methods and three deviation calculation methods are explained in detail. Six combined deviation calculation methods are used to generate compensated inputs, which are experimentally produced and compared to the uncompensated part. All different methods are able to noticeably improve the accuracy, with the production alignment and closest point deviation calculation achieving the best results


2017 ◽  
Vol 867 ◽  
pp. 177-183 ◽  
Author(s):  
Vikrant Sharma ◽  
Ashish Gohil ◽  
Bharat Modi

Incremental sheet forming is one of the latest processes in sheet metal forming industry which has drawn attention of various researchers. It has shown improved formability compared to stamping process. Single Point Incremental Forming (SPIF) process requires only hemispherical tool and no die is required hence, it is a die-less forming process. In this paper experimental investigation on SPIF for Aluminium sheet has been presented. A groove test on Vertical Machining Centre has been performed. Factors (Step depth, Blank holder clamping area, Backing plate radius, Program strategy, Feed rate and Tool diameter) affecting the process are identified and experiments are carried out using fractional factorial design of experiments. Effect of the factors on fractured depth, forming time and surface finish have been analyzed using Minitab 17 software.


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