KOBO Type Forming: forging of metals under complex conditions of the process

Bochniak, W.; Korbel, A.

doi:10.1016/s0924-0136(02)01033-6

Cited by 65 publications

(29 citation statements)

References 9 publications

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“…The parameters of the extrusion process were as follows: temperature 350 o C, ram speed 0.25 mm/s, frequency of the die oscillation was changed within the range of 5-8 Hz, oscillation angle of 4 deg, extrusion ratio 25 which corresponded to true strain of 3.2. More detailed information on the koBo method is given elsewhere [19][20][21][22].…”

Section: Methodsmentioning

confidence: 99%

Aging Behaviour Of AA6061/SiCP Composites Produced By Direct Extrusion With A Reversibly Rotating Die Method

Woźniak¹,

Kostecki²,

Broniszewski³

et al. 2015

Archives of Metallurgy and Materials

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This paper discusses the influence of thermal treatment parameters on mechanical properties of AA6061+x% vol. SiCp (x = 0, 2.5, 5, 7.5, 10) composites. The composites were consolidated via powder metallurgy processing using the unconventional method of extrusion (the koBo method). In order to establish the optimum parameters of the heat treatment two different temperatures of supersaturation (530 and 558 o C) were applied. The aging curves were determined at various aging temperatures such as 140, 160, 180 and 200 o C. The effects of applied parameters were studied using the microstructure observations and hardness measurements. Obtained results show that the solution treatment at 530 o C is sufficient to complete dissolution of the precipitates. Higher temperature of the process resulted in accelerating the aged-hardening. The suitable age treating parameters for the AA6061-5 vol. % SiCp composites were 160 -180 o C for 12 -16 hours.

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Section: Methodsmentioning

confidence: 99%

Aging Behaviour Of AA6061/SiCP Composites Produced By Direct Extrusion With A Reversibly Rotating Die Method

Woźniak¹,

Kostecki²,

Broniszewski³

et al. 2015

Archives of Metallurgy and Materials

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“…The materials were produced in the form of long rods with diameter equal to 8 mm using the KoBo method [8][9][10][11]. Two series of composites with slightly different technological parameters were taken into account.…”

Section: Tests Detailsmentioning

confidence: 99%

Fatigue Damage of Al/SiC Composites - Macroscopic and Microscopic Analysis

Rutecka

Kowalewski

Makowska

et al. 2015

Archives of Metallurgy and Materials

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The results of comparative examinations of mechanical behaviour during fatigue loads and microstructure assessment before and after fatigue tests were presented. Composites of aluminium matrix and SiC reinforcement manufactured using the KoBo method were investigated. The combinations of two kinds of fatigue damage mechanisms were observed. The first one governed by cyclic plasticity and related to inelastic strain amplitude changes and the second one expressed in a form of ratcheting based on changes in mean inelastic strain. The higher SiC content the less influence of the fatigue damage mechanisms on material behaviour was observed. Attempts have been made to evaluate an appropriate fatigue damage parameter. However, it still needs further improvements.Keywords: fatigue, damage, metal matrix composites, microstructure W artykule zaprezentowano wyniki mechanicznych badań w warunkach zmęczenia oraz badań mikrostrukturalnych przed i po testach zmęczeniowych. Badaniom poddano kompozyty o osnowie aluminiowej wzmocnionej węglikiem krzemu SiC wyprodukowane przy użyciu metody KoBo. Zaobserwowano kombinację dwóch mechanizmów uszkodzenia zmęczeniowego. Pierwszy związany z cykliczną plastycznością, a co za tym idzie ze zmianami amplitudy odkształcenia niesprężystego oraz drugi wyrażający się w formie ratchetingu oparty na zmianach średniego odkształcenia niesprężystego. Zaobserwowano również słabnący wpływ mechanizmów uszkodzenia zmęczeniowego na zachowanie badanego kompozytu wraz ze wzrostem zawartości SiC. Podjęto próbę oszacowania odpowiedniego parametru uszkodzenia zmęczeniowego, jednakże wymaga on dalszych udoskonaleń.

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“…In fact, in recent years, a growing interest is observed in metal forming processes assisted by cyclic loading. The so-called KOBO-type forming proposed by Korbel and Bochniak [9][10][11][12]47] and applied to extrusion of tubes and wires has demonstrated essential advantages with respect to classical forming processes. The significant reduction of required load, growth of ductility, fine grain structure are main beneficial factors, cf.…”

Section: Introductionmentioning

confidence: 99%

Constitutive modeling of cyclic deformation of metals under strain controlled axial extension and cyclic torsion

Mróz

Maciejewski

2017

Acta Mech

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The present work provides a formulation of a constitutive model for metals with the aim to simulate cyclic deformation under axial extension or compression assisted by cyclic torsional (or shearing) straining of specified amplitude and frequency. Such a mode of deformation was recently implemented in technological processes such as extrusion, forging and rolling, cf. Bochniak and Korbel (Eng Trans 47:351-367, 1999, J Mater Process Technol 134:120-134, 2003, Philos Mag 93:1883-1913, 2013, Mater Sci Technol 16:664-674, 2000. The constitutive model accounting for combined hardening (isotropic-kinematic) with both hardening and recovery effects is presented and calibrated for several materials: pure copper, aluminum alloy (2024), and austenitic steel. The experimental data are used to specify model parameters of materials tested, and next the cyclic response for different shear strain amplitudes is predicted and confronted with empirical data. The constitutive model is developed in order to simulate technological processes assisted by cyclic deformation.

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KOBO Type Forming: forging of metals under complex conditions of the process

Cited by 65 publications

References 9 publications

Aging Behaviour Of AA6061/SiCP Composites Produced By Direct Extrusion With A Reversibly Rotating Die Method

Aging Behaviour Of AA6061/SiCP Composites Produced By Direct Extrusion With A Reversibly Rotating Die Method

Fatigue Damage of Al/SiC Composites - Macroscopic and Microscopic Analysis

Constitutive modeling of cyclic deformation of metals under strain controlled axial extension and cyclic torsion

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