Possibilities Of Possibilities Of Aluminium Extrusion Aluminium Extrusion By The ECAP MethodBy The ECAP Method
Miroslav Greger - VŠB – Miroslav Greger - VŠB – Technical University Technical University oof Ostravaf Ostrava
Stanislav Rusz - VŠB – Stanislav Rusz - VŠB – Technical University Technical University oof f OstravaOstrava
IntroductionIntroduction
The technology ECAP allows to The technology ECAP allows to obtain an ultra-fine grain in larger obtain an ultra-fine grain in larger volumes,volumes, moreover without change moreover without change of original cross-section of the input of original cross-section of the input
semi-product.semi-product. It is possible to use It is possible to use the obtained materials in automotive the obtained materials in automotive industry, in military and aerospace industry, in military and aerospace
industries.industries.
Principles Principles oof ECAPf ECAP
Fig. 1. Schematic illustration of equal channel Fig. 1. Schematic illustration of equal channel angular pressing angular pressing process process (ECAP)(ECAP)
Principles Principles oof Shearing f Shearing oon n Passage Passage TThrough hrough tthe ECAP Diehe ECAP Die
Route A
Route BA
Route C
Route BC
90°
180°
90°
Fig. 2. The four processing routes in ECAPFig. 2. The four processing routes in ECAP
Shearing Patterns Associated Shearing Patterns Associated wwith ith tthe Different Processing he Different Processing
RoutesRoutes
Fig. 3. Shearing associated Fig. 3. Shearing associated byby a single passage a single passage through the diethrough the die
X
Y
Z
Y
Z
X
Z plane
Y plane
X plane
Influences of the Forming Influences of the Forming Parameters on Plastic Parameters on Plastic
DeformationDeformation
Influence of inner energyInfluence of inner energy Non-homogeneity of deformationNon-homogeneity of deformation Density of dislocationDensity of dislocation Concentration of vacanciesConcentration of vacancies
Change Change oof Dislocation f Dislocation SubstructureSubstructure
Fig. 4. Scheme of change of dislocation sub-Fig. 4. Scheme of change of dislocation sub-structure after cold deformationstructure after cold deformation
DependenciesDependencies
0K
0 dislocation density
constant
size of deformation
K
Linear dependence of Linear dependence of dislocation density:dislocation density:
Flow stress necessary for continuing of Flow stress necessary for continuing of deformation:deformation:
1
20 k G b
0 value of init. flow stress
k constant
, modulus of elasticity in shear,
Burger's vector
G b
Experimental Experimental VVerificationerification
Fig. 5. Overall view on Fig. 5. Overall view on the forming equipment the forming equipment
and dieand die
Fig. 6. Detailed view oFig. 6. Detailed view onn the extruding punch for the extruding punch for
the ECAP technologythe ECAP technology
Samples Samples ffor Extrusionor Extrusion
Fig. 7. Initial sample Fig. 7. Initial sample and samples after and samples after
extrusionextrusion
Fig. 8. Structure in the Fig. 8. Structure in the central areacentral area
50 m
Deformation ResistanceDeformation Resistance
Fig. 9. Deformation Fig. 9. Deformation resistance of the resistance of the
aluminiumaluminium
Fig. 10. Deformation Fig. 10. Deformation resistance of the alloy resistance of the alloy
AlCuMgAlCuMg
Micro-structure Micro-structure oof Sample f Sample After ExtrusionAfter Extrusion
Fig. 11. The first Fig. 11. The first passagepassage
Fig. 14. The fourth Fig. 14. The fourth passagepassage
50 m
50 m
Fig. 13. The third Fig. 13. The third passagepassage
Fig. 12. The second Fig. 12. The second passagepassage
ConclusionConclusion
Refining of grain in poly-crystalline metals.Refining of grain in poly-crystalline metals. Micro-structure obtained by ECAP method Micro-structure obtained by ECAP method
depends on:depends on: Using of more passes and turning of the sample.Using of more passes and turning of the sample. Extruding the sample by 4 or more passes.Extruding the sample by 4 or more passes.
Optimal angle between horizontal and vertical Optimal angle between horizontal and vertical channel of the part is ≈ 90 degrees. Radius of fillet channel of the part is ≈ 90 degrees. Radius of fillet of the extrusion channel must correspond to of the extrusion channel must correspond to conditions for steady flow of metal.conditions for steady flow of metal.
Strain rate has only partial influence on Strain rate has only partial influence on deformation resistance and small influence on deformation resistance and small influence on micro-structure.micro-structure.
Practical Illustration Practical Illustration oof f tthe he ECAP MethodECAP Method by by
Mathematic Modeling Mathematic Modeling
Fig. 15. The example of stress intensity by Fig. 15. The example of stress intensity by the the simulation process of the AlCuMg extrusion simulation process of the AlCuMg extrusion (1st and 2nd sample)(1st and 2nd sample)
Practical Illustration Practical Illustration oof f tthe he ECAP MethodECAP Method by by Mathematic Mathematic
ModelingModeling
Fig. 16. The example Fig. 16. The example of of shear stresses shear stresses ppartition artition byby the the ECAP method (1st a 2nd sample)ECAP method (1st a 2nd sample)
Practical Illustration Practical Illustration oof f tthe he ECAP MethodECAP Method by by Mathematic Mathematic
ModelingModeling
Fig. 17. Contact pressure between sample and Fig. 17. Contact pressure between sample and tools tools for for AlCuMg alloy by the ECAP methodAlCuMg alloy by the ECAP method (1st a (1st a 2nd sample)2nd sample)
Practical Illustration Practical Illustration oof f tthe he ECAP MethodECAP Method by by
Mathematic ModelingMathematic Modeling
Fig. 18. Fig. 18. The example of the dThe example of the deformation intensity eformation intensity ofof AlCuMg AlCuMg alloyalloy by the ECAP method (1st a 2nd by the ECAP method (1st a 2nd sample)sample)
Practical Illustration Practical Illustration oof f tthe he ECAP MethodECAP Method by by Mathematic Mathematic
ModelingModeling
Fig. 19. The Fig. 19. The exexample of the lay-out of ample of the lay-out of temperature of AlCuMg alloy by the ECAP temperature of AlCuMg alloy by the ECAP method (1st a 2nd sample)method (1st a 2nd sample)
Thank you for your attentionThank you for your attention
Top Related