Anomalies in precipitation hardening process of 7075 aluminum alloy extruded by KOBO method

Korbel, A.; Bochniak, W.; Borowski, Jacek; Błaż, L.; Ostachowski, Paweł; Łagoda, М.

doi:10.1016/j.jmatprotec.2014.09.008

Cited by 25 publications

(20 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The tests conducted so far have shown that there is a possibility to shape magnesium alloy with very big deformations without the need of prior heating of the charge. What is more, the achieved products are characterised with high resistance properties and good plastic properties [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

The Influence of Extrusion Process on the Microstructure and Mechanical Properties of Magnesium Alloys

Bednarczyk¹,

Kuc²,

Tomaszewska³

et al. 2017

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

The article presents the results of plastic shaping tests of AZ61 and WE43 alloys. There were both classic extrusion tests as well as extrusion tests of KOBO method. An assessment was made of the influence of extrusion process parameters on the mechanical properties and the structure of the alloys. On the basis of achieved results of mechanical properties for alloys AZ31 and WE43 the susceptibility of those alloys to plastic shaping was determined. Quantitative tests of structure assessment in case of alloys AZ61 and WE43 after extrusion with the use of KOBO method were conducted with the use of METILO program. It has been shown that extrusion AZ61,WE43 alloys method KOBO leads to considerable fragmentation of grains.

show abstract

Section: Introductionmentioning

confidence: 99%

The Influence of Extrusion Process on the Microstructure and Mechanical Properties of Magnesium Alloys

Bednarczyk¹,

Kuc²,

Tomaszewska³

et al. 2017

Archives of Metallurgy and Materials

View full text Add to dashboard Cite

show abstract

“…Their level depends on process parameters, particularly on the extrusion force, which reacts strongly to the frequency of die oscillation [39]. In turn, the process of KOBO extrusion of heat-treatable aluminum alloys eliminates their initial precipitation hardening of AA6013 [42], or as in the case of AA7075 alloy [71], "removes the effects of previous treatments." Meanwhile, the high hardness of Cu1Cr0.1Zr alloy, in commercial state, is preserved at a similar level in rods extruded by the KOBO method at low temperatures, and this parameter reacts weakly to annealing (aging).…”

Section: Commentarymentioning

confidence: 99%

Strength properties and structure of CuCrZr alloy subjected to low-temperature KOBO extrusion and heat treatment

Ostachowski

Bochniak

Łagoda

et al. 2019

Int J Adv Manuf Technol

View full text Add to dashboard Cite

KOBO extrusion of metals and alloys strongly activates the point defect generation processes, as a result of which they reach a concentration exceeding the equilibrium level by many orders of magnitude. This leads to significant acceleration of diffusion phenomena which in heat-treatable alloys may cause disturbance of the thermodynamic equilibrium between the solid solution decomposition and dissolution of precipitates. In this work, measurements of mechanical and electrical properties and structural observations Cu1Cr0.1Zr alloy subjected to low-temperature KOBO extrusion at different stages of multi-variant heat treatment were conducted. In addition, the geometry of the extruded alloy's flow zone was analyzed and the obtained results made it possible to assess the effectiveness of experimental procedures, including product formation with high extrusion ratio λ, aimed at achieving of high and thermally stable functional properties of the material.

show abstract

“…For the last few years, different methods of severe plastic deformation (SPD) have been successfully applied to light metal alloys without preheating, and a spectacular increase in the mechanical properties due to refining the grain size to a submicroscale, and even nanoscale has been obtained [8][9][10][11][12]. One of them is the KoBo method (i.e., cold extrusion with a forward-backward rotating die), which is used for different metallic material processes.…”

Section: Introductionmentioning

confidence: 99%

Effect of Magnesium Matrix Grain Refinement Induced by Plastic Deformation in a Composite with Short Carbon Fibers

Olszówka-Myalska

Kuc

Myalski

et al. 2019

Metals

View full text Add to dashboard Cite

The magnesium matrix composite reinforced with 3 vol. % of short carbon fibers (Csf), fabricated, under industrial conditions, by the stir casting method, was applied to obtain composite bars by two extrusion methods: the novel method of cold severe plastic deformation with a forward-backward rotating die (KoBo) and conventional extrusion at 400 °C. The effect of Mg(α) grain refining, as well as fibers behavior and phenomenon at the fiber-matrix interface, was examined by optical microscopy, scanning electron microscopy with energy dispersive spectroscopy and scanning-transmission electron microscopy methods. The Mg(α) grain quantitative characteristics revealed a decrease of the equivalent diameter from 219 ± 76 μm (as-cast) to 24 ± 10 μm and 0.89 ± 0.35 μm (the hot-extruded and KoBo-processed, respectively). In addition, due to the KoBo application, except for the Csf orientation that was parallel to the extrusion direction, an effect of fibers fragmentation on the length of few Csf diameters was detected. No significant changes in the Csf-matrix interface (besides those between new carbon surfaces) formed by fibers fragmentation, and the matrix created by extrusion were detected. A comparison of the mechanical properties of the Mg-Csf composite showed that the KoBo method ensured a spectacular increase in strength and plasticity.

show abstract

Anomalies in precipitation hardening process of 7075 aluminum alloy extruded by KOBO method

Cited by 25 publications

References 16 publications

The Influence of Extrusion Process on the Microstructure and Mechanical Properties of Magnesium Alloys

The Influence of Extrusion Process on the Microstructure and Mechanical Properties of Magnesium Alloys

Strength properties and structure of CuCrZr alloy subjected to low-temperature KOBO extrusion and heat treatment

Effect of Magnesium Matrix Grain Refinement Induced by Plastic Deformation in a Composite with Short Carbon Fibers

Contact Info

Product

Resources

About