Experimental Facilities and Activities in the VI IPSUS

Transcription

1 Experimental Facilities and Activities in the VI IPSUS W. Reimers, S. Müller Technical University Berlin Institute of Materials Science and Technology - Metallic Materials - - Extrusion Research and Development Center -

2 Fields of Competence Extrusion R & D Center Extrusion of profiles, samples, semi-finishes products Optimization of extrusion parameters Simulation of the extrusion process Microstructure Charaterization (dislocations, grain size, texture, residual stress) Microscopy (SEM, TEM, EBSD) Diffractometry (X-ray, synchrotron, neutrons) Mechanical Testing Static and dynamic testing High speed and high temperature testing Corrosion tests Wear tests

3 Equipment Extrusion R & D Center 3 extrusion presses Billet heating 0.5 MN direct/ indirect Chamber furnace 8 MN direct/ indirect Induction furnace 7.2 MN hydrostatic

4 Equipment Mechanical Testing Tension and compression testing up to max 100 kn, servo-hydraulic up to 1400 C, 2 zones up to 2000 C, induction heating Creep testing up to max 50 kn servo-electrical up to 1100 C, continous mode High speed and high temperature testing Gleeble 3800 system maximum force: 200 kn up to +100 kn maximum stroke rate: 2000 mm/sec maximum temperature of specimen: C maximum heating rate: C/sec

5 Equipment Microstructure Charaterization Different X-ray diffractometers Texture analysis Residual stress analysis Phase analysis SEM SEM equipped with EDX SEM equipped with EBSD TEM TEM equipped with EDS

6 Influence of the extrusion method on the deformation resistance Direct / Indirect T B = 370 C, v Prod = 5 m min -1, AZ31 Indirect / Hydrostatic T B = 250 C, v Prod = 5 m min -1, AZ31 Deformation Umformwiderstand resistance k w k [MPa] w [MPa] k (Gesamt) w (total) k w (die) k w (Matrize) indirect indirekt direct direkt Deformation Umformwiderstand resistance k w [MPa] k w [MPa] indirect indirekt hydrostatic hydrostatisch 80 k w, max k w, stat 130 k w, max k w, stat Direct larger k w, max (total) because of additional friction lower k w, stat because of higher T Indirect larger k w, max because of upsetting k w, stat equal because of higher T

7 Influence of the cooling on the microstructure Average mittlere Korngröße grain size [ m] [ m] Cross Querschliff sec. Longitudinal Längsschliffsec. Air 10 Air Luft Wasser Water Increase in cooling speed Water Decrease of the grain size Decrease of grain size difference between longitudinal and cross section Single fiber texture

8 Influence of the Al content on the microstructure AZ31 AZ61 Increase in Al content Decrease of the grain size Slight decrease of texture intensity AZ80

9 Influence of the Al content on the mechanical properties Stress [MPa] Zug Ten. (AZ31) -0,40 Zug Ten. (AZ61) Zug Ten. (AZ80) Druck Comp. (AZ31) Druck Comp. (AZ61) -0,35 Druck Comp. (AZ80) -0,30-0,25-0,20-0, Strain [%] SDE SDE Al Gehalt [Gew. %] Al Content [%] Increase in Al content Increase of CYS, TYS, UCS, UTS Decrease of fracture strain Linear decrease of SDE

10 Grain refinement by ECAE Twinning dependent on the grain size Reduction of the grain size Stem Kneading die Sample Die Container 1. Predeformation Upsetting 2. Predeformation Upsetting Extrusion Rod N 1 0,89 2 1,87 3 2,68 4 3,57 5 4,46 6 5,35 7 6,25 8 7,14 9 8, ,93

11 Extrusion into a counter pressure Twinning dependent on the texture Variation of the texture during the extrusion I 8 I II Sealing Filling & bulding up of the pressure II III Total extrusion force [MN] 7 III Extrusion into a constant counter pressure with a counter pressure 1 without a counter pressure Ram displacement [mm] Registered for patent (AZ ) 70

12 Texture and mechanical properties Max = 4, w/o counter pressure Max = 10, with counter pressure Stress [MPa] % w/o ohne counter Gegendruck/ pressure Druck /comp. w/o ohne counter Gegendruck/ pressure Zug/ten. with mit Gegendruck/ counter pressure Druck/comp. with mit Gegendruck/ counter pressure Zug /ten Strain [%] Occurance of a {0001} texture pole Increase of the CYS by 50 %

13 In-situ Tomographie (AA6061, 22% Al 2 O 3, extruded) Creep strain [%] Kriechdehnung? cr [%] mm t=8280s t=0s Kriechzeit cr t [s] Creep time [s] t=20520s T cr =360 C? cr =30MPa X Bruch t=23900s

14 WP 1 - Activities Coextrusion of hybrid (Mg/ Al) profiles Interlayer selection Compression tests with various interlayers at high temperatures Microstructure analysis of the interlayer and base material (Ex-situ) Extrusion Variation of the extrusion parameters Mechanical Testing Disengaging tests

15 WP 2 - Activities Implementation of FlexStir System at HARWI 2 Beamline at Desy slit collimator beam 2D-detector (diffraction) sample 2D-detector (tomography) Synchrotron beam at HARWI-II energy range: 20 bis 200 kev beam breadth: 50 mm beam highth: 10 m 2D-detector (diffraction)

16 WP 3 - Activities In-situ diffraction and tomography Analysis of the influence of extrusion parameters on recrystallization Analysis of the influence of extrusion parameters on precipitates In-situ SAXS analysis Al Mg Interlayer T > 200 C