The Effect of Ultrasonic-Vibration on Upsetting

2006 ◽  
Author(s):  
Jung-Chung Hung ◽  
Yu-Chung Tsai ◽  
Chinghua Hung
Keyword(s):  
Aluminum Alloy ◽  
Ultrasonic Vibration ◽  
Compression Test ◽  
Cylindrical Specimen ◽  
Compressive Force ◽  
Specimen Size ◽  
Experimental Results ◽  
Ring Compression Test ◽  
Interface Friction ◽  
Ring Compression

Ultrasonic-vibration upsetting is a process in which a cylindrical specimen is compressed by an axial force while the ultrasonic vibration is simultaneously applied to the die. Homogenous deformation is difficult to achieve during this process because of the friction at the interface between the specimen and the die. An extrapolated compression test was performed in this study on aluminum alloy specimens to explore the effect of superimposing ultrasonic-vibration during upsetting. Experimental results indicate that ultrasonic-vibration reduced the compressive force when the friction was eliminated by the extrapolated compression test. The specimen size also influences the force-reducing effects of ultrasonic-vibration. The decrease in the compressive force is smaller for a larger specimen. The barreling profile of the specimen after test indicates that the interface friction will increase during ultrasonic-vibration compression. Additionally, the raised material temperatures are caused by ultrasonic-vibration. Experimental results of the hot extrapolated compression test and the hot ring compression test indicate that the drop in the flow stress and the increase in the interface friction are caused by the increase in the temperature of the material under ultrasonic vibration.

FEM Simulation Analysis of Ring Compression Test Using Stationary and Rotating Die under Constant Shear Friction

2020 ◽  
Vol 830 ◽  
pp. 15-28
Author(s):  
Wayne Stalls ◽  
Un Chin Chai ◽  
Tim Pasang ◽  
Gow Yi Tzou
Keyword(s):  
Friction Factor ◽  
Compression Test ◽  
Simulation Analysis ◽  
Metal Flow ◽  
Fem Simulation ◽  
Compressive Force ◽  
Reduction Ratio ◽  
Ring Compression Test ◽  
Ring Compression ◽  
Friction Calibration

The main objective of this research was to investigate the effect of friction on the behaviour of the metal flow and ring geometry, using comparisons from a stationary and rotating bottom die. This was carried out using friction calibration curves, compressive force analysis, stress and strain relationships and the reduction ratio of the ring specimen. The ring compression test (RCT) is considered one of the most reliable ways to obtain the friction factor existing in a plastic deformation process. This technique utilizes the dimensional changes of a test specimen to determine the magnitude of the friction factor. The variation of the calibration curve for the stationary die, with a range of m=0.0 to 0.9, and for the rotating die a range of m=0.1, 0.5 and 0.9. The frictional factor is calculated using FEM analysis, friction calibration and reduction ratio curves were generated from the compressive force using the DEFORM software package. The results indicated that the change in the inner diameter is related to the friction conditions and angular velocities at the die-workpiece interface.

Friction and Flow Behavior of Ceramics in Ring-Compression Test

2010 ◽  
Vol 154-155 ◽  
pp. 1752-1756
Author(s):  
Hui Gai Wang ◽  
Fei Wang ◽  
Yan Pei Song ◽  
Kai Feng Zhang
Keyword(s):  
Compression Test ◽  
Smooth Surface ◽  
Flow Behavior ◽  
Reference Value ◽  
Experimental Results ◽  
Ring Compression Test ◽  
Surface Polishing ◽  
Ring Compression ◽  
Ultra Precision ◽  
Application Scope

Float polishing is one of the advanced ultra-smooth surface polishing techniques. Mechanical structure and polishing principle of float polishing are introduced. Polishing experiment about polishing ultra-smooth surface of GCr15 rectangular workpiece is performed by the CJY500 ultra-precision polishing machine, experimental results show that float polishing should be achieved metal nanometer level surface without degenerating layer. The application scope of float polishing is extended, the application has significant reference value for polishing ultra-smooth surface of metal workpiece.

Evaluation of Friction Properties of Magnesium Alloy during Hot Forging by Ring Compression Test

2017 ◽  
Vol 889 ◽  
pp. 119-126
Author(s):  
Sueji Hirawatari ◽  
Hisaki Watari ◽  
Shinichi Nishida ◽  
Yuki Sato ◽  
Mayumi Suzuki
Keyword(s):  
Magnesium Alloys ◽  
Compression Test ◽  
Hot Forging ◽  
Hot Forming ◽  
Compression Tests ◽  
Ring Compression Test ◽  
Stress Strain ◽  
Friction Coefficients ◽  
Ring Compression ◽  
Velocity Motion

This paper deals with friction properties and deformation resistance during hot forming of Mg-Al-Ca-Mn series magnesium alloys. Friction coefficients between dies and magnesium alloys were obtained by ring compression tests that used graphite, PTFE, and an oil lubricant in a hot-forging process. Hot forging was performed under various conditions to clarify the effects of types of lubricants and slide motion of the press machines on friction properties. Two types of slide motion, a constant velocity motion and a pulse motion were selected in the ring-compression test. It was found that graphite with an oil lubricant effectively eliminated die sticking in hot forming of magnesium alloys. The isothermal deformation resistances were derived using friction coefficients obtained by ring-compression tests as well as finite-element simulations. The predicted stress strain curves with temperature were examined with the stress-strain relationship obtained in experiments using a servo press and demonstrated the effectiveness of the proposed method.

scholarly journals Studies on friction behaviour of aluminium AA4032 alloy during forging using ring compression test

2021 ◽  
Vol 13 (3) ◽  
pp. 23-36
Author(s):  
Desalegn Wogaso ◽  
Mohammed Hamda
Keyword(s):  
Friction Factor ◽  
Metal Surface ◽  
Palm Oil ◽  
Compression Test ◽  
Metal Flow ◽  
Work Piece ◽  
Ring Compression Test ◽  
Ring Compression ◽  
Friction Behaviour ◽  
Selection Of

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.

scholarly journals Evaluation of Cold Forging Lubricants for Steel by Ring Compression Test with Rotating Die

2018 ◽  
Vol 59 (687) ◽  
pp. 53-58
Author(s):  
Masatoshi SAWAMURA ◽  
Yasuhiro YOGO ◽  
Michiaki KAMIYAMA ◽  
Noritoshi IWATA
Keyword(s):  
Compression Test ◽  
Cold Forging ◽  
Ring Compression Test ◽  
Ring Compression

Effect of lubrication on hardness in the ring compression test

2015 ◽  
Vol 230 (12) ◽  
pp. 1939-1950 ◽  
Author(s):  
CH HariKrishna ◽  
MJ Davidson ◽  
CH Nagaraju ◽  
B Anil Kumar
Keyword(s):  
Boric Acid ◽  
Strain Hardening ◽  
Compression Test ◽  
Hardness Distribution ◽  
Simulation Studies ◽  
Ring Compression Test ◽  
Ring Specimen ◽  
Ring Compression ◽  
Different Types ◽  
Metallic Ring

This paper focuses on the hardness distribution in the AA2014-T6 ring specimens upset under rigid dies. Three different types of lubricants namely soap, boric acid and vaseline were employed as lubricants and the friction factor corresponding to the lubricant employed was evaluated using standard ‘Ring compression test’. The strain distributions obtained from the simulation studies were used to predict the hardness inside the ring specimen. The hardness measured experimentally was validated with the predicted hardness and it was found that the errors in the predicted results were less than 10%. The hardness variations inside the upset metallic ring specimens were compared with the deformed solid cylinders to understand the behavior of differential strain hardening. It can be reported from the experimental and predicted results that the hardness is not uniform inside the deformed ring specimen and it varies at the bulge head; on the surface and along the neutral plane.

Development of a Testing Method for the Identification of Friction Coefficients for Numerical Modeling of the Shear-Clinching Process

2015 ◽  
Vol 639 ◽  
pp. 469-476 ◽  
Author(s):  
Martin Müller ◽  
Ulrich Vierzigmann ◽  
Réjane Hörhold ◽  
Gerson Meschut ◽  
Marion Merklein
Keyword(s):  
Compression Test ◽  
Manufacturing Industry ◽  
Dissimilar Materials ◽  
High Strength Steels ◽  
High Strength ◽  
Ring Compression Test ◽  
Friction Coefficients ◽  
Testing Method ◽  
Ring Compression ◽  
Joining Process

Global competition as well as social and scientific megatrends strongly influence the modern car manufacturing industry. One of the most important approaches is the implementation of lightweight constructions. Therefore, the usage of high performance materials with tailored properties gains importance. For safety-relevant components such as automotive passenger cells it is necessary to minimize deformation to reduce the risk of injury for the vehicle occupants during a car accident. Thus, hot stamped high-strength steels have been established. High-strength and low formability of this kind of materials represent new challenges for joining technologies. One possibility to join high-strength steels is the newly developed shear-clinching technology. Due to the use of a combined cutting and joining process, the connection of dissimilar materials with high difference in strength and formability can be achieved. Further research to ensure process reliability and to improve the strength of the joint is required. One possible approach for this is the numerical investigation of the material flow during the joining process. Therefore, the definition of process parameters for the finite element model is necessary. A big impact on the quality of the results has the accuracy of the used friction values. As established testing methods are not suitable for modeling the rather complex tribological system between the joining partners of the shear-clinching process, an innovative testing method is needed. Studies in the field of sheet-bulk metal forming already demonstrated the applicability of the ring compression test for sheet metals. This paper presents a concept for the adaption of the ring compression test to the specific needs of the investigated shear-clinching process. The numerical identification of the friction coefficients is validated by experimental data and first results are qualified by experimental and simulative shear-clinching joints.

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