NANO Ostrava 2008NANO Ostrava 2008(1 – 4. 9. 2008)(1 – 4. 9. 2008)

Refining of structure of the alloy AlMn1Cu with Refining of structure of the alloy AlMn1Cu with

use of multiple severe plastic deformationuse of multiple severe plastic deformation

S. Rusz, K. Malanik, J. Kedroň

VSB – Technical university of Ostrava, Faculty of Mechanical Engineering, Czech Republic

VUHZ Dobra a. s. , Czech Republic

Principle of the Equal Channel Angular PressingPrinciple of the Equal Channel Angular Pressing (ECAP)(ECAP)

p - load - angle of transition of 2 channels - angle of outside rounding of the channel

R1 – outer radiusR2 – inner radiusb – channel widthb1 – channel width between roundings

Fig. 2 Channel parametersFig. 1 Channel angles

p

Mathematical simulation of the SPD processMathematical simulation of the SPD process

●● Existing state of development of Existing state of development of simulationsimulation

3D simulation of extrusion by the ECMAP process 3D simulation of extrusion by the ECMAP process

Fig. 3 Obtained amount of deformation for 3 types of passes

11

22

33

44

55

66

11 Pressure roller Pressure roller 22 Supporting insertSupporting insert Feed rollerFeed roller33 44 Formed materialFormed material

Insert of forming toolInsert of forming tool55 66 Fastening casingFastening casing

Fig. 4 CONFORM processFig. 4 CONFORM process

Principle of the ECAP technologyPrinciple of the ECAP technology

●● Channel parameters:Channel parameters:

R1 – outer radiusR1 – outer radiusR2 – inner radiusR2 – inner radiusØØ – inside angle of 2 channels – inside angle of 2 channelsΨΨ – angle of rounding of the outer channel – angle of rounding of the outer channelb – channel width b – channel width p - load p - load

Fig. 6 Channel geometryFig. 6 Channel geometryFig. 5 Pass - Fig. 5 Pass - type „Bc“

●● Types of passes :Types of passes :

- A, B- A, Baa, B, Bcc, C, C

Parameters required for mathematical simulationParameters required for mathematical simulation

●● Boundary conditions:Boundary conditions:

- Tool temperature :- Tool temperature : TTnn = 20 and 350°C = 20 and 350°C

- Temperature of blank:- Temperature of blank: TTpp = 20 and 350°C = 20 and 350°C

- Ambient temperature:- Ambient temperature: TToo = 20°C = 20°C

- Tool material:- Tool material: SKD 61SKD 61

- Material of sample:- Material of sample: AlMn1CuAlMn1Cu

- Friction coefficient:- Friction coefficient: f = 0.1f = 0.1

- Rate of extrusion: - Rate of extrusion: v = 0.5 mm/s v = 0.5 mm/s

Fig. 7 ECAP tool arrangementFig. 7 ECAP tool arrangement

Simulation of the ECAP process Simulation of the ECAP process – alloy AlMn1Cu– alloy AlMn1Cu

R1 = 4 mm

R2 = 0.5 mm

b = 10 mm

Ø = 90°

Ψ = 90°

Fig. 8 Design of suitable forming tool geometryFig. 8 Design of suitable forming tool geometry

Effective Plastic StrainEffective Plastic Strain after the 1after the 1stst pass of the type B pass of the type Bcc

Full section 50% of the section

Effective Plastic Strain of the alloy AlMn1Cu at Effective Plastic Strain of the alloy AlMn1Cu at 20°C and 4 passes20°C and 4 passes

11stst pass pass 22ndnd pass pass

33rdrd pass pass 4th pass

Effective Plastic Strain

Effective Plastic Strain

Effective Plastic Strain

Effective Plastic Strain

Effective Plastic Strain of the alloy AlMn1CuEffective Plastic Strain of the alloy AlMn1Cu at at 350°C and 4 passes 350°C and 4 passes

11stst pass pass 22ndnd pass pass

33rdrd pass pass 44thth pass pass

Effective Plastic Strain

Effective Plastic Strain

Effective Plastic Strain

Effective Plastic Strain

Obtained values of Effective Plastic Strain Obtained values of Effective Plastic Strain

inin dependence on temperature, classical geometry dependence on temperature, classical geometry of channelof channel

TemperaturePass „Bc“

1. 2. 3. 4.

20°C 1.1 2.1 2.9 3.7

350°C 1.05 2.1 2.9 3.6

Modification of tool geometry Modification of tool geometry for increased amount of deformationfor increased amount of deformation

Fig. 9Fig. 9 ECAP tool with deflection of 20°ECAP tool with deflection of 20°

Channel geometryChannel geometry

R1 = 4 mmR1 = 4 mm

R2 = 0.5 mmR2 = 0.5 mm

R3 = 5 mmR3 = 5 mm

b = 10 mmb = 10 mm

ØØ = 90° = 90°

ΨΨ = 90° = 90°

Effective Plastic Strain of the alloy AlMn1Cu Effective Plastic Strain of the alloy AlMn1Cu at 20°C and 4 passes, channel deflection 20°at 20°C and 4 passes, channel deflection 20°

11stst pass pass 22ndnd pass pass

33rdrd pass pass 44thth pass pass

Effective Plastic StrainEffective Plastic Strain

Effective Plastic StrainEffective Plastic Strain

Magnitude of deformation intensity of the alloy Magnitude of deformation intensity of the alloy AlMn1Cu at 350°C and 4 passes, AlMn1Cu at 350°C and 4 passes,

channel deflection 20°channel deflection 20°

1st pass 2nd pass

3rd pass 4th pass

Effective Plastic StrainEffective Plastic Strain

Effective Plastic StrainEffective Plastic Strain

Obtained Values of Effective Plastic Strain Obtained Values of Effective Plastic Strain in dependence on temperature, channel deflection 20°in dependence on temperature, channel deflection 20°

TemperaturePass „Bc“

1. 2. 3. 4.

20°C 1.25 2.3 3.3 4.3

350°C 1.25 2.3 3.4 4.3

Overall comparison of resultsOverall comparison of results

Temperature / channel deflection

Pass „Bc“

1. 2. 3. 4.

20°C 1.15 2.1 2.9 3.7

350°C 1.2 2.1 2.9 3.6

20°C / 20°- deflection 1.25 2.3 3.3 4.4

350°C / 20° - deflection 1.25 2.3 3.4 4.3

Obtained values of Effective Plastic Strain in dependence on Obtained values of Effective Plastic Strain in dependence on temperature, channel geometry and number of passestemperature, channel geometry and number of passes

Metallographic analysis on AFM microscopeMetallographic analysis on AFM microscope

Fig. 10 Microstructural analysis a) after the 3rd pass b) after the 4th pass through the ECAP tool

a) b)

ConclusionConclusion

●● Growth of deformation intensity was obtained at extrusion of sample alloys Growth of deformation intensity was obtained at extrusion of sample alloys through the ECAP tool after through the ECAP tool after multiple multiple passes. In conformity with theoretical passes. In conformity with theoretical assumptions greater number of passes results in substantial growthassumptions greater number of passes results in substantial growth..

●● No influence of temperature on obtained deformation intensity was detected No influence of temperature on obtained deformation intensity was detected after individual passesafter individual passes..

●● Modified tool geometry aimed at increase of the value of effective Modified tool geometry aimed at increase of the value of effective plastic strain (20° offset of horizontal part of the channel)plastic strain (20° offset of horizontal part of the channel) enabled enabled substantial increase of sample deformation already after the first pass and substantial increase of sample deformation already after the first pass and subsequent passes through the ECAP tool, which contributes significantly to subsequent passes through the ECAP tool, which contributes significantly to enhancement of the SPD process efficiency. This value achievesenhancement of the SPD process efficiency. This value achieves 16-18% of 16-18% of growth in individual passes.growth in individual passes.

●● According to the input analysis of microstructure of extruded samples the According to the input analysis of microstructure of extruded samples the process brought substantial refinement of grain to the final size process brought substantial refinement of grain to the final size ddaverageaverage= 250-300 nm, from the input grain size 20-30 mm.= 250-300 nm, from the input grain size 20-30 mm.

Thank you for your attentionThank you for your attention