The research of single point incremental forming process for composite mould production/Vieno tasko palaipsnio formavimo proceso tyrimas kompozitu formoms gaminti.

1.
Today, if enterprises want to survive in the fierce competition in the manufacturing industry, they must constantly improve the technical process.
On the other hand, the constant change and growth of customer demand makes the enterprise not only pursue high quality, high efficiency, but also pursue flexible technology.
The increased demand for mass customization of composite materials has driven the trend of low cost, lighter
Development of weight, durable composite tools and away from traditional tools.
Aluminum sheet blanks can be used in mold production for composite structure manufacturing, which greatly reduces the manufacturing cost and tooling time. [1].
Although there are many ways of forming the sheet, not all methods are suitable for small batch production, especially the production of composite molds.
For example, traditional technologies such as stamping or deep punching require significant investment and are not flexible.
In this case, each production of the mold requires special technical equipment, which greatly increases the manufacturing time and cost.
The new sheet metal forming technology uses simple and flexible tools to create a prototype of a product and a variety of complex shapes.
These technologies are calledless forming.
Gradual forming of plates (ISMF)
It is effective for prototyping and small batch production.
Also, it is very flexible with low settings onlyup costs [2, 3].
Simple ISMF applications require traditional cnc milling machines, relatively simple equipment and tools.
In addition, researchers are constantly improving the technology to make it more applicable. 1-6].
Although the Journal of Science has published a large number of publications in this area, the technology has not yet been fully researched because it depends on various non-
Constant parameters.
As we all know, the efficiency of ISMF and the quality of the prototype depend on the process parameters and the performance of the processed materials [4].
Some researchers focus on the optimization of tool paths, believing that it helps to improve product quality while reducing manufacturing costs.
The influence of tool paths in traditional machining techniques is well known and discussed in various scientific publications.
However, at present, researchers insist that tools are one of the most important factors affecting the quality of ISMF technical processes5, 6].
On the other hand, this technology has been further developed, adding new factors that affect the quality and efficiency of the process.
Robot ISMF is one of the alternative products to manufacture complex geometry sheet metal products.
In this case, the standard CNC machining center is replaced by one or several robots, which makes this technology more flexible [7].
While the technology was originally intended for soft metal, there are a number of publications currently discussing its efficiency in hard processingto-
Formation of titanium sheet.
In this case, hardto-
Apply additional heating of tools or sheet metal [to process forming materials]8].
In this case, there are two additional parameters: the temperature and lubrication between the tool and the formed material.
In addition, some additional measures have been taken to improve the efficiency of soft sheet metal processing, E. G. g.
Cuts of various shapes [9].
Forming of plates, especially single point progressive forming (SPIF)
, Very depends on the rigidity of sheet metal formed [10].
The surface parameters of the products formed, that is, roughness, are important indicators of quality, especially for mold production.
Since eismf is a contact processing method, the roughness of surface processing depends on the process, the tool, the shape of the prototype and the parameters of the material.
In order to make products with poor surface quality, roughness prediction and analytical thinking become extremely important.
The analytical roughness evaluation model designed allows the prediction of roughness in the early manufacturing phase [11].
However, crack prediction is also important because the closed profile of the product does not always go smoothly.
Fracture due to extreme tension of sheet metal can be prevented only by simulating and selecting appropriate process parameters in the early stage of manufacture [12].
Although ISMF is not the only alternative technology that can be used in the production of composite molds (
Fast, cheap and flexible tools are also known as Fast tools in various papers [13-15])
This technology offers many opportunities for low-investment composite tools.
This paper analyzes the material forming features related to the geometric shape changes of forming parts.
The main task of this paper is to find the best process state of single point incremental process for composite mold production.
On the other hand, at least few materials need to be tested due to different forming properties. 2.
The design and construction of the SPIF tool six different types of ISMF technology can be used based on blank fixing, brackets, and the number of tools used in the process.
This is the easiest process when Sheet metal forming methods require only one tool and do not require any support called SPIF.
Although this method is the simplest, it ensures a high enough quality and the process is very flexible and capable of producing molds of different shapes. The frame (Fig. 1)
The process equipment for experimental testing is designed.
This fixation allows local deformation of the processed paper and keeps it in its initial position throughout the process.
The working area of the design equipment is 170x170mm.
The maximum height of the prototype is 100mm.
The tool used to form sheet metal is fixed in the middle of the CNC milling machine.
Tools used to handle different surfaces vary depending on their shape and size of the working parts. Fig.
2 shows three types of tools.
The sphere end tool is usually used to make different shape elements.
The plane tool is used for the processing of the plane and the formation of the angle.
The ball end tool with a smaller diameter is designed to form a smaller precise element.
The diameter of the tool has a great influence on the forming process.
Tools with smaller working parts radius have better forming properties.
Using smaller tools, since the heat released is highly localized, the material becomes more stretched and shaped.
However, due to the strength of the tool material and the ability to resist bending fatigue, the radius of the tool cannot be reduced to an infinite length.
On the other hand, smaller tools mean more manufacturing time.
During the manufacturing process, the tool can rotate or reverse it in the direction of motion.
The direction of rotation affects the surface quality.
In the case of
If you rotate in motion, the surface will produce additional deformation.
The metal heats up to a large extent, and its structure changes and the surface becomes rough.
So sports-
Use the wise direction of rotation more often.
In this case, try to match the rotation and sliding speed of the tool.
In this way, the tool works under rolling friction, reducing heat emission and improving the quality of the machined parts.
On the other hand, the tool may not be brought into forced rotation at all.
In this case, the tool is fixed on the spindle and moves freely.
Here, because of the friction between the tool and the machined part, the tool appears to rotate. 3.
Methods due to the lack of information on the selection of working status in the literature, this work focuses on analyzing the practical application of SPIF in sheet metal mold production.
The technical system was set up in the experiment.
The process only involves sheet metal forming, so the processing system may be significantly higher than that of metal cutting.
When it causes rolling friction, the ratio of movement and rotation speed is considered to be optimal.
However, it should be considered that, due to the spherical surface of the tool, it is almost impossible to roll friction using an spherical knife.
On the other hand, there is a view that forming improves when the temperature of tools and materials that use lower systems or are processed increases [12].
Some other parameters (e. g. tollpath)
This may affect the quality of the machined parts during the experiment.
This experiment should be prepared with the help of specific CAMsystems, which allow the generation of various toolpaths.
But it should be noted that there is no optimal toolpath for all prototypes, so changes in geometry may require different toolpaths.
In addition, the tool trajectory not only affects the processing efficiency, but also affects the quality of the surface of the part.
The spiral toolpath is used for all experiments as it is considered to be the best choice shape for the mold prototype.
One of the most important parameters of the mold--
Wall thickness depends on the thickness of the processed material and the angle of tool forming [beta]
Forming height h, etc (Fig. 3).
As we all know, the formation process becomes more complicated when the angle [beta]
Get closerto 90 [degrees].
In this case, the walls become thinner and may break.
Therefore, the shear forming wall thickness prediction equation related to the forming angle can be used [16]:[t. sub. f]= [t. sub. 0]sin (90 -[beta]), (1)where [t. sub. 0]
Is the thickness of the plate before forming, mm; [beta]
Is the angle of formation, degree; [t. sub. f]
Predict sheet metal thickness after operation, mm.
The influence of tool moving steps on sheet metal forming is still under discussion.
The main assumption is that the shorter the forming, the greater the forming and vice versa [17].
Roughness is another important indicator of surface quality, and it is also very important for composite molds.
Tool to z (vertical)
The shaft is one of the main factors affecting the surface roughness.
The surface roughness also depends on the shape and shape of the tool.
It is important to mention that spherical tools with smaller diameters produce components with high quality surfaces, but they greatly increase manufacturing costs and time.
Then select the vertical tool move step z0, you can calculate z1 as follows :[z. sub. 1]= [z. sub. 0]/sin[beta], (2)where [beta]
Is the angle of formation, degree;
Z0 is the tool moving step in the z axis direction, mm; z1 -
Tool movement steps related to the forming angle, mm.
Then, the predicted surface roughness can be calculated according [9, 15]. [R. sub. z]= 125 [z. sup. 2. sub. 1](3)
The predicted roughness of the machined parts is Lim, Lim;
Radius of tool working parts, mm.
Usually, this formula has only 10% error between prediction and actual roughness.
In addition, it is also observed that the surface roughness will be higher without useRotating tool]18].
The surface roughness can be reduced, and the relative movement between the tool and the workpiece can be reduced.
In fact, once each surface can be used for the production of composite structures, it is important to determine the roughness of the inner and outer walls.
The surface in contact with the tool here is called the inner surface.
Mold surface hardness is another important parameter that affects the quality of the composite mold.
By using spiiftechnology, the material is plastic deformed and hardened on the surface.
During the experiment, aluminum alloy was used for mold production, and in order to improve the mechanical properties of the mold, the change of mechanical properties of the material was analyzed. 4.
The experimental test was carried out on the CNC machine tool DMU 35 m.
The processing program was developed using MasterCam 9 software.
The experimental equipment is shown in the figure. 4.
Two different materials were used in the experimental analysis.
For the first experimental part, the second part analysis was performed using aluminiumEN AW5754 and EN AW1050 DDQ.
Two different materials were selected due to different molding properties.
Stepover was later changed and the forming of the part was checked to find the highest forming angle.
The first part of the experiment was carried out using a fixed working state.
The spindle rotation direction matches the movement direction.
Spindle speed-
The speed is 400 rpm and the feeding speed is 400/min. 300 mm/min.
According to the displacement in the x-direction, the tool movement in the z-axis direction is recalculatedy axis (stepover).
The result is 0.
8mm during the first type of experiment.
Stepover was subsequently reduced and the molding was checked.
In the first part of the AW5754 aluminum experiment, a circular-like part was formed.
In all the experiments, the depth of h = 40mm formed by the prototype remained unchanged. Formingangle [beta]varied from 42[degrees]to 85[degrees].
In addition, it should be noted that the maximum size of the forming area in the direction of the x and y axes remains unchanged --170x170 mm.
However, the part size selected in the x and y axes is 100x100mm.
Support plates that limit sheet metal forming are also used.
The first experiment was carried out on the aluminum AW5754 material, and the chemical composition is shown in Table 1.
The mechanical properties of the formed materials are shown in Table 2.
The aluminum AW 5754 has good forming properties and is therefore used for deep punching and rolling.
However, it should be emphasized that a single point progressive forming can produce a greater stretch than the deep drawing method.
Another material used in the experiment is aluminum AW 1050 DDQ.
This material is common in deep punching techniques because the elongation can reach 35%. Fig.
5 shows the correlation between the forming depth and the forming angle.
As mentioned earlier, the forming depth remains the same in all cases.
The picture shows that only two parts avoid fracture.
However, when the angle of formation exceeds 53 [degrees]
The depth of formation decreased significantly.
In all cases, the face looks very similar.
They are in figs. 6.
However, the location of the fracture is different.
When the maximum 85 [angle] is formeddegrees]
There is a fracture around the corner.
It should be mentioned that under the radius of r = 20mm, the corner of the formed part is round.
At the same time, when the forming angle is 63 °,degrees]
The first fracture occurs on a straight surface.
In this case, a corner is formed smoothly before a fracture occurs. Fig.
7 shows the distribution of sheet metal thickness when the forming angle is 42 [degrees].
As shown in the figure, the maximum reduction in thickness is 1.
09mm, this thickness is sufficient to ensure good mechanical performance of the formed parts.
Nikon L-measuring thickness per 5mm by microscope
I\'m Pixelink PL with a professional microscope-A662.
Analytical Calculation of sheet metal wall thickness. (1)
Prediction 1 is given after formation. 11 mmthickness. Fig.
8 shows the distribution of sheet metal thickness when the forming angle is 63 [degrees].
In the first case, a measurement is made every 5mm metres.
It may be important to note that in this case, the sheet metal is lengthened more and the thickness is only 0.
The thinnest place 65mm
This may be considered edge thickness due to it causing fracture.
Measuring the wall of the prototype with the forming angle of 76 [degrees]indicated 0.
65mm thickness in their thinnestplace.
Therefore, it can be said that the maximum reduction of 1.
5mm thick aluminum alloy AW5754 plate up to 0.
This type of SPIF process is 65mm.
Analytical Calculation of wall thickness when forming angle is 63 [degrees]
The predicted thickness is 0. 68 mm.
The results show that the wall thickness of the prediction is almost the same as that obtained by experience, hence the equation. (1)
Can be used for early prediction in product design and manufacturing phases.
Measuring the wall of an unbroken part with a forming angle 76 [degrees]
, Indicating that the thickness is 0. 42 mm.
However, analytical calculations are performed using the equation. (1)
The predicted wall thickness is 0. 36 mm.
But Eq should be mentioned. (1)
Specially used for the prediction of wall thickness of Shear forming parts.
It should be noted that when the wall thickness of the molded part is less than 0.
7mm micro-fractures can occur.
These structural defects affect the mechanical properties and quality of the mold
Quality of molded composite material.
Such a deep part (
More than 50mm depth)
Due to the risk of micro-cracking, it is not possible to form from maluminium AW5754.
Therefore, another part of the experiment was carried out with aluminum aw1050.
In this case, better forming performance was found.
In this case, the working state is constant: the spindle speed is 400 rpm, the feed speed-
400/min, crash rate 300/min0. 8 mm. Fig.
Figure 9 shows the relationship between the forming depth and the forming angle.
However, it is necessary to reduce the working mechanism when macro fracture occurs.
Further experiments show that the angle of formation is 75 [degrees]
It can be obtained with stepover of 0. 4mm.
In addition, after these experiments, it can be concluded that the AW1050 material has better forming performance compared to AW5754 and can be used to produce deeper molds that do not take into account high mechanical loads.
SPIF is a very effective technology compared to hard tool manufacturing.
For example, a part is formed with a 75 angle [degrees]
It takes 54 minutes for the depth of 93mm.
The traditional molding process (only roughing)
It could take more than 2 hours.
Plastic deformation of the metal allows the production of complex molds.
Therefore, the structure and mechanical properties of aluminum alloy have also undergone great changes.
Known hardness of aluminum-
Mg Alloy increased by 20-
Plastic deformation after 30%.
However, the data in the graph
10 shows that the hardness of the material AW5754 is increased by about 60% after deformation.
The change in hardness of AW1050 is very similar.
When the mold thickness is 0
The hardness of 7mm is about 60% high.
In order to determine the surface quality, the surface ripples on both sides of the forming parts with different forming angles are measured (Fig. 11).
It is noted that the corrugated degree of the inner surface is lower compared to the outer surface.
In addition, if the tool distance is reduced, the wave degree will also be reduced.
It can be noted that the angle of formation is 76 [degrees]
Waves on the surface increased significantly.
Since two forms are used in this case, such results are obtained.
This helps to increase the forming angle, but also the ripple is significantly increased.
Therefore, the application of this multi-channel method may be limited by the surface quality requirements of the mold. 5.
The results and conclusions are mainly based on empirical data.
Experiments were carried out with AW5754 and AW1050 aluminum alloys, so other materials may produce different results.
The conclusions of the experimental study may help to develop new and innovative products in the advanced rapid production field of rapid prototyping, tools and customized composite structures.
The following conclusions can be drawn from the research done: 1.
This method can be used for the rapid production of composite structure molds.
Compared with traditional tool manufacturing technology, this technology can reduce manufacturing time and manufacturing costs. 2.
The molding of the mold depends to a large extent on the forming angle and mechanical properties of the forming material.
AW5754, the angle of formation can be 53 [degrees]
, But for the material aw1050, the forming angle can be 75 [degrees]
Then a forming channel is used.
The angle can be higher when two forming channels are used. 3.
The analysis of the degree of formed surface wave shows that it is feasible to produce high quality molds and prototypes. E. g.
The surface wave degree Rt of AW1050 alloy in single forming mode varies from 20 to 52 Lim. 10. 5755/j01. mech. 20. 4.
7045 confirmation received In March 21, 2014 accepted In August 20, 2014 this study was conducted by the European Social Fund In the project \"In-Smart\" (
Protocol number vp13. 1-SMM-10-V-02-012). References[1. ]Fiorotto, M. ; et al. 2010.
Preliminary Study on single point progressive forming of composite materials, International Journal of Material forming 3,1: 951-954. [2. ]Luo, Y. ; He, K. ; Du, R. 2010.
New sheet metal forming system based on incremental stamping, Part II: Mechanical Manufacturing and experimental results, International Journal of Advanced Manufacturing Technology 51: 493-506. [3. ]Emmens, W. C. ; et al. 2010.
Progressive forming technology of sheet-
Journal of Materials Processing Technology Issue 210: issue 981997. [4. ]Giuseppina, A. ; et al. 2010.
Prediction of progressive forming process performance by neural network method, International Journal of Advanced Manufacturing Technology 54: 921-930. [5. ]Rauch, M. ; et al. 2009.
Optimization of tool path programming for incremental sheet forming applications
Design Assistance 41: 877-885. [4. ]Li M. ; et al. 2011, Tool -
Process path generation method for sheet metal progressive forming, material research innovation 15: 278-282. [6. ]Meier, H. ; et al. 2009.
Improve the accuracy of robot parts
CIRP Annals-Incremental sheet metal forming based
Manufacturing Technology 58: 233238. [7. ]Fan G. ; et al. 2010.
Incremental forming of Ti-electric heating6Al-
4 V titanium sheet, International Journal of Advanced Manufacturing Technology 49: 941-947. [8. ]Allwood, M. J. ; Braun, D. ; Music, O. 2010.
Effect of partial cutting
Blank of geometric accuracy in incremental forming, Journal of Material Processing Technology 210: 1501-1510. [9. ]Hussain, G. ; Lin, G. ; Hayat, N. 2010.
A new parameter in a single point progressive forming and its effect on shaping.
A basic survey by the Journal of Mechanical Science and Technology 24: 16171621. [10. ]Durante, M. ; Formisano, A. ; Langella, A. 2010.
Comparison of analytical and experimental values of surface roughness of incremental forming components, Journal of Material Processing Technology 210: 1934-1941. [11. ]Silva, M. ; et al. 2011.
Failure Mechanism in metal single point forming, International Journal of Advanced Manufacturing Technology 56: 893-903. [12. ]Bahattin, K. ; Sridhar, T. 2011.
Design and Analysis of configurable three-mode discrete PIN tooling system
Free size
Objects, robots and computers
Integrated Manufacturing 27: 335348. [13. ]Kumar, S. 2009.
Manufacturing of WC
Journal of Material Processing Technology 209: 3840-Co mold using SLSmachine3848. [14. ]Wang. ; et al. 2011.
A method of representing the geometry of parts using discrete pins that can reconfigure the mold is proposed in engineering software 42: 409-418. [15. ]Jeswiet, J. 2005.
Advanced Material Resaerch 6-asymmetric Incremental sheet forming8: 35-58. [16. ]Ham, M. ; Jeswiet, J. 2006.
Standard for single point incremental formation and formation of AA3003, CIRP Annals 55: 214-244. [17. ]Hagan, E. ; Jeswiet, J. 2004.
Surface roughness analysis of computer numerical control progressive forming parts. Proc. IMechE.
Journal of Engineering Manufacturing 218: 1307-1312. M.
Rimasauskas *, K. Juzenas **, R.
Rimasauskiene *, E.
Kaunas University of Technology, Lithuania stucio 27,44312 Kaunas, Lithuania, E-mail: marius. Ktu rimasauskas @.
Kaunas University of Technology, Lithuania stucio 27,44312 Kaunas, Lithuania, E-
Postage: kazimieras. juzenas@ktu.
Kaunas University of Technology, Lithuania stucio 27,44312 Kaunas, Lithuania, E-mail: ruta.
Ktu rimasauskiene @.
Kaunas University of Technology, Lithuania stucio 27,44312 Kaunas, Lithuania, E-mail: edmundas. pupelis@ktu.