AA6013 aluminium alloy deformed by forward-backward rotating die (KoBo): Microstructure and mechanical properties control by changing the die oscillation frequency

Koprowski, P.; Bieda, M.; Boczkal, Sonia; Jarzębska, Anna; Ostachowski, Paweł; Kawałko, Jakub; Czeppe, T.; Maziarz, W.; Łagoda, М.; Sztwiertnia, K.

doi:10.1016/j.jmatprotec.2017.10.043

Cited by 12 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The application of additional reversible torsion of die by a given angle, at specific frequency ( Fig. 1) results in some strain caused by die torsion leading to the existence of viscoplasticity effect of the material [27][28][29][30][31]. The essence of KoBo method is the change of strain path, which leads to the change of stress and results in lower extrusion force.…”

Section: Introductionmentioning

confidence: 99%

“…[36] Superplastic type of metal flow makes it possible to obtain a high quality product, even with complex shapes. As a result, a product is obtained with high plastic properties, suitable for further, direct forming operations [23,30,32]. The great advantage of the process compared to classical SPD and extrusion methods is to obtain the product in a single step [30][31][32][33][34], at room temperature and with properly reduced cross sections, even for hardly deformable materials [e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The great advantage of the process compared to classical SPD and extrusion methods is to obtain the product in a single step [30][31][32][33][34], at room temperature and with properly reduced cross sections, even for hardly deformable materials [e.g. 30,32]. In case of extrusion of chips there are two issues: the necessity of their compaction up to solid state and recreation of joints between individual chips in order to form bulk material/product, which requires inducing a cyclic change of strain path in each of them.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mechanical Properties of Product From 7075 Aluminum Chips After Consolidation by Kobo Method

Pawłowska¹

2020

Acta Metall Slovaca

View full text Add to dashboard Cite

This paper presents the possibility of consolidating side products of turning of aluminum alloys into the form and properties of solids metals using low-temperature KoBo extrusion method has been assessed.The proposed method is based on cold compaction of chips into briquettes, and then extrusion by KoBo method at room temperature. The extruded wires were tested for mechanical properties (uniaxial tensile test and Vickers hardness test), and compared with specific mechanical properties of solid material. A very good effect of chips compaction has been proved by KoBo method, which has been confirmed by relatively slightly different mechanical properties of the material after consolidation compared with the solid one.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanical Properties of Product From 7075 Aluminum Chips After Consolidation by Kobo Method

Pawłowska¹

2020

Acta Metall Slovaca

View full text Add to dashboard Cite

show abstract

“…This oscillating rotary motion of a die is the only difference comparing to traditional direct extrusion. KOBO extrusion method results in a significant reduction of extrusion force and obtained product is characterized by much greater fine-grained structure and ductility than in case of the conventional process [3,4]. During KOBO extrusion, a large number of point defects occur, which remain in the extruded material as nano-sized clusters.…”

Section: Introductionmentioning

confidence: 99%

Experimental Analysis of Mechanical Characteristics of KOBO Extrusion Method

Balawender

Zwolak²,

Bąk³

2020

View full text Add to dashboard Cite

The paper presents selected results of KOBO extrusion process of circular profile ϕ10 mm from aluminum alloy 2099. The main aim of the performed research was to determine the influence of the oscillation frequency of a die on the magnitude of extrusion force. During the process such parameters, as extrusion force, rate of stem and frequency of die oscillation were recorded; oscillating angle of a die was constant and equal ±8°. The die oscillation frequency was changeable in performed tests in the range of 2 ÷ 7 Hz. The obtained results allowed to determine the relation between the maximum extrusion force and the die oscillation frequency during extrusion of aluminum 2099 alloy.The paper focuses on the experimental analysis of mechanical characteristics of the KOBO process. Basing on the recorded force versus stem position, three stages of KOBO extrusion process were determined, i.e. initialization, stabilization and uniform extrusion. Points separating these stages are two inflection points of recorded diagram. The analysis of each stage was made basing on the results of force diagrams and literature data.

show abstract

“…The great advantage of the process compared to classical SPD and extrusion methods is to obtain the product in a single step [30][31][32], at room temperature and with properly reduced cross sections, even for hardly deformable materials. It is believed that, during process a new mechanism of deformation called visco-plastic flow occurs [33].…”

Section: Introductionmentioning

confidence: 99%

Archives of Metallurgy and Materials

Pawłowska¹,

Śliwa²,

Zwolak³

2019

View full text Add to dashboard Cite

Basing on experimental data, the possibility of consolidating side products of turning, milling and drilling of aluminum alloys into the form and properties of solids metals using low-temperature KoBo extrusion method has been assessed. Research regarding mechanical and structural properties of the final products revealed their total consolidation and proved their compatibility with requirements for products made of bulk billets. Importantly, the chips consolidation process does not require high or even raised temperature, which significantly reduces the unfavorable phenomenon of chips oxidation and its negative influence on the structure and mechanical properties of products. A very good effect of chips compaction has been proved by KoBo method, which has been confirmed by relatively slightly different mechanical properties of the material after recycling compared with the bulk one. Among currently applied techniques of consolidation of dispersed fractions in a solid state (leaving the melting stage out), the KoBo method seems an innovative way of utilizing metallic chips, as it enables a cold deformation process.The paper presents investigations using 2024 and 7075 aluminum alloys chips from manufacturing process, formed into briquettes and deformed under conditions of KoBo extrusion process, which enables to obtain long product by cold forming. The final product characterized by good microstructures, mechanical features and low cost of production.

show abstract

AA6013 aluminium alloy deformed by forward-backward rotating die (KoBo): Microstructure and mechanical properties control by changing the die oscillation frequency

Cited by 12 publications

References 19 publications

Mechanical Properties of Product From 7075 Aluminum Chips After Consolidation by Kobo Method

Mechanical Properties of Product From 7075 Aluminum Chips After Consolidation by Kobo Method

Experimental Analysis of Mechanical Characteristics of KOBO Extrusion Method

Archives of Metallurgy and Materials

Contact Info

Product

Resources

About