Utilization of Ring Compression Test to Investigate the Mushroom Effect and Adhesive Nature of AA2014 Billets

2018 ◽  
Vol 1148 ◽  
pp. 96-102
Author(s):  
Ch. Harikrishna ◽  
M.J. Davidson ◽  
P. Srinivasa Raju ◽  
G. Srinivasa Rao
Keyword(s):  
Finite Element ◽  
Compression Test ◽  
Cold Forging ◽  
Outer Diameter ◽  
Ring Compression Test ◽  
Molybdenum Disulphide ◽  
H13 Steel ◽  
White Grease ◽  
Ring Compression ◽  
Different Levels

In the cold forging of AA2014, friction at the die/billet interface plays a significant role. AA2014 metallic rings of height 8 mm with an outer diameter of 24 mm and inner diameter of 12 mm was upset between H13 steel dies to different levels of deformation. Different types of lubricants namely, grease, molybdenum disulphide, white grease, palm oil were employed at the die/ring interface and ring compression test was also conducted for un lubricated condition. The values based on the changes in the geometry after different levels of deformation were fit into Male and Cockroft calibration curves to estimate the friction factor (m). The values of friction factors determined from the experiments were given as input to the finite element package, Deform 2D. The results obtained from the finite element studies were compared with the experimental results. After validation, the research was extended by considering ring geometries of different sizes. The effect of the friction between the die/billet interface and geometry were studied on the flow of metal. The zone of minimum velocity of particles, defined as neutral plane was analyzed for different friction conditions and different geometries of the ring.

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

An Investigation of Thin Film Coating for Evaluation Friction Coefficient Using Ring Compression Test

2012 ◽  
Vol 152-154 ◽  
pp. 1281-1286 ◽  
Author(s):  
Komgrit Lawanwong
Keyword(s):  
Thin Film ◽  
Coefficient Of Friction ◽  
Compression Test ◽  
Film Coating ◽  
Outer Diameter ◽  
Ring Compression Test ◽  
Thin Film Coating ◽  
Ring Compression ◽  
Reduced Height ◽  
Die Surface

This research aims to investigate the types of thin film coating for the evaluation of coefficient of friction using ring compression test. Ring compression test was used to evaluate the coefficient of friction of contact between die coating surface and workpiece material, brass grade C3771. Specimen was machined by CNC to the standard size with ratio of the outer diameter [25.4mm] to inner diameter [12.7mm] and thickness [8.5 mm] is 6:3:2. The dies were made from tool steel grade JIS SKD11 hardened to 60±2HRC then polished die surface at Ra= 0:07 to0:09 microns. Tool surface conditions selected for this research were non-coated, PVD coated DLC, AlCrN, TiCN and TiAlN.The Experiments were carried without lubricant. Experiments were reduced height of the specimen at 50 percent. It was found that Non coated condition had shown lower coefficient of friction than DLC, AlCrN, TiAlN and TiCN due to influence of surface roughness. Furthermore, thin film coated die had shown durable and high resistance scratch of die surface more than non coated die.

scholarly journals Thermo-mechanical forging of 708M40 steel ring samples: experiments and modelling

2021 ◽  
Author(s):  
Steven Hill ◽  
Richard P.Turner
Keyword(s):  
Finite Element ◽  
Experimental Parameter ◽  
Compression Tests ◽  
Molybdenum Disulphide ◽  
Heating Unit ◽  
Modelling Framework ◽  
Process Understanding ◽  
Ring Compression ◽  
Water Based ◽  
Temperature Variable

AbstractA series of ring compression tests using BS970:708M40 alloy steel samples were studied. These tests were conducted using a 2-factor soak-temperature variable, namely 1030 °C and 1300 °C, and a 4-factor lubricant variable consisting of unlubricated samples, synthetic water-based, graphite water-based, and graphite and molybdenum disulphide viscous grease. The lubricant agents were all applied to the tool/billet interface. Process variables such as blow force and heating were controlled with the use of a gravitationally operated drop hammer and an automated programmable induction-heating unit. This matrix of the experimental parameters offered a sound base for exploring dominant factors impacting upon bulk deformation. This deformation was measured using fully calibrated equipment and then systematically recorded. A finite element modelling framework was developed to further improve the thermo-mechanical deformation process understanding, with finite element (FE) predictions validated through experimental measurement. Through the combined experimental and FE work, it was shown that temperature variation in the experimental parameter matrix played a larger role in determining deformation than the lubrication agent. Additionally, the use of synthetic and graphite water-based lubricants does not necessarily produce greater deformation when used in high-temperature forgings due to the lubricants breaking down, evaporating, or inducing rapid billet cooling as a result of the carrier used (water). Graphite-molybdenum disulphate grease far outperforms the other lubricants used in this trial in reducing friction and allowing deformation to occur across a die-face.

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.

Influence of the Preforming Material State in Common Tribological Tests

2016 ◽  
Vol 1140 ◽  
pp. 75-82
Author(s):  
Bastian Zimmermann ◽  
Marion Merklein
Keyword(s):  
Compression Test ◽  
Work Hardening ◽  
Test Sample ◽  
Wire Drawing ◽  
Cold Forging ◽  
The Real ◽  
Friction Factors ◽  
Ring Compression ◽  
Material State ◽  
Rolled Wire

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.

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.

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