Lubricant Evaluation Technique for Single Point Incremental Forming Process

Author(s):  
Khompee Limpadapun ◽  
Ramil Kesvarakul ◽  
Yingyot Aue-u-lan ◽  
Thanasan Intarakumthornchai

Single-point Incremental Forming (SPIF) is highly flexible dieless forming process suitable for a small batch production. The higher the feed rate and tool rotational speed, the higher the production rate will be. Therefore, the selection of the suitable lubricant is a key important factor to maintain the formability of the material when increasing the feed rate and tool rotational speed. This paper proposes the technique to evaluate and later on select the proper lubricant for these conditions. This technique was divided into two phases; 1) screening, and 2) stabilization. The screening phase is a quick method for preliminary selection of the lubricants. The stabilizing phase is a step to evaluate reliability as well as ensure efficiency of the lubricant throughout the process, because of the significant increase of the forming temperature which affects directly to the performance of the lubricant. Two types of lubricants, namely solid (Graphite) and liquid (Callington Calform NF-206) lubricants mixed with the base oil (coconut oil) at different ratios were tested. The cold rolled hot-dipped zinc-coated steel sheet with thickness of 0.176 mm. and wall angles of 45, 50, 55 and 60 degrees with the depth of each wall angle of 5 mm were used. During the screening phase, the fifteen mixtures firstly were tested by using the achieved maximum wall angles without fracture as a criterion. Later on, the lubricant mixtures which could successfully form at the wall angle of 60 degrees with the forming depth of 20 mm would be tested in the stabilization phase to evaluate the formability and the forming temperature. The results showed that during the screening phase 11 lubricants could perform successfully, while the stabilization phase with the wall angle of 60 degrees only 3 lubricants could successfully form the workpiece. Therefore, this evaluation technique could help to evaluate and, for later on, be a criterion to select the select lubricant.

Author(s):  
Saurabh Rai ◽  
Rakesh Kumar ◽  
Harish Kumar Nirala ◽  
Kevin Francis ◽  
Anupam Agrawal

Abstract Single point incremental forming (SPIF) is more accurate and economical than the conventional forming process for customized products. Majority of the work in SPIF has been carried out on metals. However, polymers are also required to shape. Polycarbonate has wide application in safety glass, bottles, automotive and aircraft industry due to its transparent as well as attractive processing and mechanical properties as compared to other polymeric plastics. In present work, the Polycarbonate (PC) sheet of thickness 1.8 mm is deformed to make a square cup at different angles. Tensile testing is done to analyze the effect of wall angle on the deformed cup. This work illustrates the effect of the SPIF process on material strength in a different directions (vertical and horizontal) of the final deformed product. Tool forces are evaluated using ABAQUS® simulation for SPIF. Numerical simulation approach is used to calculate the fracture energy, which utilizes the force-displacement curve of the specimen and is verified.


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. 335-338
Author(s):  
Kittiphat Rattanachan ◽  
Chatchapol Chungchoo

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.


2018 ◽  
Vol 21 (1) ◽  
pp. 108 ◽  
Author(s):  
Aqeel Sabree Bedan ◽  
Halah Ali Habeeb

Incremental forming is a flexible sheet metal forming process which performed by utilizes simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. One limitations of single point incremental forming (SPIF) process is the error occur between the CAD design and the product profile. This work presents the single point incremental forming process for produced pyramid geometry and studied the effect of tool geometry, tool diameter, wall angle, and spindle speed on the dimensional accuracy. Three geometries of forming tools were used in experimental work: ball end tool, hemispherical tool, and flat with round corner tool. The sheet material used was pure Aluminum (Al 1050) with thickness of (0.9 mm). The experimental tests in this work were done on the computer numerical control (CNC) vertical milling machine. The products dimensions were measured by utilized the dimensional sensor measuring instrument. The extracted results from the single point incremental forming process indicated the best acceptance between the CAD profile and product profile was found with the ball end tool and diameter of (10 mm), wall angle (50°) and the rotational speed of the tool was (800 rpm).


2019 ◽  
Vol 14 (2) ◽  
pp. 1-13
Author(s):  
Aqeel S Sabree Bedan ◽  
Halah Ali H Habeeb

Incremental forming is a flexible sheet metal forming process which is performed by utilizing simple tools to locally deform a sheet of metal along a predefined tool path without using of dies. This work presents the single point incremental forming process for producing pyramid geometry and studies the effect of tool geometry, tool diameter, and spindle speed on the residual stresses. The residual stresses were measured by ORIONRKS 6000 test measuring instrument. This instrument was used with four angles of (0º,15º,30º, and 45º) and the average value of residual stresses was determined, the value of the residual stress in the original blanks was (10.626 MPa). The X-ray diffraction technology was used to measure the residual stresses. The sheet material used was Aluminum alloy (AL1050) with thickness of (0.9 mm). The experimental tests in this work were done on the computer numerical control (CNC) vertical milling machine. The extracted results from the single point incremental forming process were analyzed using analysis of variance (ANOVA) to predict the effect of forming parameters on the residual stresses. The optimum value of the residual stresses (55.024 MPa) was found when using the flat end with round corner tool and radius of (3 mm), wall angle of (55°) and a rotational speed of the tool of (800 rpm). The minimum value of the residual stresses (24.389MPa) was found when using hemispherical tool with diameter of (12 mm), wall angle of (45°) and a rotational speed of the tool of (800 rpm).  


2016 ◽  
Vol 68 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Valentin Oleksik

Abstract The current paper aims to study, using numerical simulation, the influence of the wall angle on the single point incremental forming process. For the analysis there has been used the LS-Dyna software and three explicit dynamic analyses were run for three parts with wall angles of 450, 550 and 650. The factors taken into account are the main strains, the thickness reduction and the forces on three directions. The material data introduced into the simulation were determined based on an uniaxial traction test on an Instron 5587 testing machine and the Aramis system was used as optical extensometer.


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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