Analysis of Friction Factor in Cold Forging by using Ring with Triangular Boss Compression Test

Author(s):  
Rashmi Dwivedi ◽  
Mohneesh Choudhary ◽  
Kuldeep Sahgal ◽  
Rajesh Purohit
2021 ◽  
Vol 13 (3) ◽  
pp. 23-36
Author(s):  
Desalegn Wogaso ◽  
Mohammed Hamda

In metal forming, friction has a negative effect on the deformation load & energy requirements, homogeneity of metal flow, quality of formed surfaces, etc.; however, its effect can be reduced through the use of proper lubricants. Mostly, in industrial applications, selection of proper lubricant for specific material is challenging and quantification of magnitude of friction at diework piece interface is essential. Hence, for metallic alloys, a realistic friction factor is needed to be known and used at the diework piece interface for better control of deformation process. Thus, this research, generally, aims at experimental investigation of the friction behavior of aluminum AA4032 alloy and selection of suitable lubricant for its effective processing using ring compression test and finite element (FE) simulations. Meanwhile, the effect of metal surface conditions and different lubricants namely palm oil, grease, emulsion oil and dry conditions on the friction behaviour has been evaluated. A commercial FEM software, DEFORM 3D, is used to analyze the flow of metal, determine the geometry changes of the specimen and generate friction calibration curves. The results revealed that the nature of metal surface and lubricating conditions have significantly affected the metal flow pattern, deformation load requirement, induced effective stress and strain, and geometry of the metal. The friction factor at die-work piece is determined for different lubricating conditions. Among lubricants employed, palm oil is found to be suitable and effective for industrial processing of aluminium AA4032 alloy, specifically for forging. The FE simulation results are in a good agreement with the experimental one.


2016 ◽  
Vol 1140 ◽  
pp. 75-82
Author(s):  
Bastian Zimmermann ◽  
Marion Merklein

Different tests to determine friction factors for cold forging processes are given in the literature. The double cup extrusion test, the ring compression test and the T-shape compression test are three of the common tests, which are compared in this investigation. From former investigations it is known that there is an influence of the work-hardening of the test sample on the friction factor, which is determined by the test. At this study, the influence of the work-hardening of the material on the three named tests is investigated by using a wire drawing process. In addition, the drawn wire from the originally thermo mechanical rolled wire is also annealed to have a second material state without any work-hardening. The used material and its numerical modelling as well as the analyzed tribological conditions of the real specimens are described. Afterwards the three test setups are explained for the numerical as well as for the real experiments. In the end, the influence of the drawing respectively the work-hardening for the three tests is presented and discussed.


2018 ◽  
Vol 59 (687) ◽  
pp. 53-58
Author(s):  
Masatoshi SAWAMURA ◽  
Yasuhiro YOGO ◽  
Michiaki KAMIYAMA ◽  
Noritoshi IWATA

2014 ◽  
Vol 939 ◽  
pp. 473-480
Author(s):  
Peter Groche ◽  
Christoph Müller ◽  
Mira Keller

Cold forging is a highly efficient process to produce components. However, the occurring tribological loads are tremendous. Therefore, complex tribological systems are necessary. They can be influenced by numerous factors. Most important are the tribological loads, which can usually be investigated independently. On the other hand, the contact normal stress and the surface enlargement are coupled in tribometer tests. In order to investigate them independently, a new concept for the Sliding Compression Test is presented and verified. This procedure reveals that both values have an influence on the friction coefficient. However, the influence of the surface enlargement is with about two-thirds higher.


2011 ◽  
Vol 704-705 ◽  
pp. 967-972
Author(s):  
Hui Gai Wang ◽  
Yan Pei Song ◽  
Fei Wang ◽  
Kai Feng Zhang

Using ring compression tests, the interfacial friction and flow stress of 3Y-TZP/Al2O3 composite at elevated temperatures were investigated. Theoretical calibration curves of the friction factor and the relative average pressure curves for the ring compression tests of 6:3:2 standard rings were drawn based on a velocity field capable of describing the bulge phenomena. The lubricant was the boron nitride (hexagonal). The tests were adopted at temperature range of 1400°C-1600°C. Results indicate that the interfacial friction factor has the value in the range of 0.34-0.49, so that boron nitride lubricant can be used effectively in present temperatures. As two extremely important parameters, the temperature and strain rate have no significant effect on the fraction factor. It is proved reliable that the ring-compression test at 1400°C and even higher is used to evaluate the performance of boron nitride lubricant.


2013 ◽  
Vol 135 (3) ◽  
Author(s):  
K. H. Jung ◽  
Y. T. Im

In cold bulk forming processes, a constant shear friction model is widely used to apply friction. However, it is not easy to predict the shear friction factor since frictional behavior is highly nonlinear and is dependent upon a number of processing variables, such as the hardness of the material, lubricity, sliding velocity, surface contact conditions, and the environment, etc. This paper presents a dimensionless equation that predicts the shear friction factor at the counter punch interface mfd that was empirically determined by dimensional analysis, using the tip test results available in the literature as a function of selected process variables, such as the yield strength and initial specimen's radius of the deforming material, hardness, and surface roughness of the deforming material and the counter punch, viscosity of the lubricant, and deformation speed. To verify the determined equation, a new set of experiments were carried out for specimens made of AL7075-O. The prediction of the shear friction factor at the punch interface was also achieved by simply dividing the dimensionless equation by the x ratio defined by x = mfd/mfp, which is dependent on the hardening exponent of the deforming material based on previous studies. The predicted mfd and mfp were found to be reasonable owing to comparisons with the experimental data obtained for AL7075–O in this study. These results will be beneficial in scientifically assessing the effect of the processing parameters on the friction, individually and economically selecting the lubrication condition for cold bulk forming for practical applications.


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