Poster Vito ESA_draft
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Tensile static properties Experimental setup Laser metal deposition setup • Coaxial powder nozzle • 1kW fiber laser with 1,2 mm focal spot size • Glove box filled with argon Sample geometry and scan strategy • Horizontal and vertical orientation • 90 rotation of fill tracks Post LMD • Heat treatments: 2h @ 850-950-1020C followed by furnace cooling (850C) or air cooling (950-1020C) • Machining by electro-discharge machining or milling Material Properties after Laser Metal Deposition of Ti6Al4V M. Rombouts 1 , L. Thijs 2 , M. Strantza 3 , C. Li 2 , B. Vrancken 2 , J. Van Humbeeck 2 1 Department of Materials Technology, Vito, Mol (Belgium) 2 Department of Materials Engineering, Katholieke Universiteit Leuven, Leuven (Belgium) 3 Department of Mechanics of Materials and Constructions, Vrije Universiteit Brussel, Belgium Microstructure • No significant pick-up of oxygen, nitrogen or hydrogen during LMD (Instrumental Gas Analysis) • Only a few small, spherical pores • X-Ray Diffraction after LMD • Mainly a hexagonal phase (+ bcc b in vertical oriented part) • High crystallographic texture: <-12-10> preferentially along build direction and <0001> // scanning directions • Elongated prior b grains along build direction after LMD Build direction Z Scan direction X Scan direction Y Acknowledgement Research funded by SBO Project grant 110070: eSHM with AM of the Agency for Innovation by Science and Technology (IWT) 2h 950C, AC 2h 850C, FC Z Effect of machining & HT sequence Effect of loading orientation & HT Crack growth during four point bending Horizontal • Relatively strong & ductile material behavior for vertical oriented part • Heat treatments lower the strength & increase the elongation • 850C: fine Widmanstätten α+β with discontinuous β phase; grain boundary α • 950C: coarse Widmanstätten α+β structure with grain boundary α in columnar structure Milling is preferred above EDM EDM + HT: harder, more brittle surface layer (~ 440-470 HV ↔ 360 HV in centre) Corner notch Bottom Side • Crack initiation (@ 17.8 kN, 16 kN and 14.4 kN) ~ 4,5 times faster for LMD sample compared to conventional Ti6Al4V • Crack propagation (@ 13kN) ~ 3 times faster for LMD sample compared to conventional Ti6Al4V + EDM HT@950C Vertical - Top Z
Transcript of Poster Vito ESA_draft
Tensile static properties
Experimental setup Laser metal deposition setup
• Coaxial powder nozzle
• 1kW fiber laser with 1,2 mm focal spot size
• Glove box filled with argon
Sample geometry and scan strategy • Horizontal and vertical orientation
• 90 rotation of fill tracks
Post LMD • Heat treatments: 2h @ 850-950-1020C followed by furnace cooling (850C) or air cooling (950-1020C)
• Machining by electro-discharge machining or milling
Material Properties after Laser Metal Deposition of Ti6Al4V
M. Rombouts1, L. Thijs2, M. Strantza3, C. Li2, B. Vrancken2, J. Van Humbeeck2 1 Department of Materials Technology, Vito, Mol (Belgium) 2 Department of Materials Engineering, Katholieke Universiteit Leuven, Leuven (Belgium) 3 Department of Mechanics of Materials and Constructions, Vrije Universiteit Brussel, Belgium
Microstructure • No significant pick-up of oxygen, nitrogen or hydrogen during LMD (Instrumental Gas Analysis)
• Only a few small, spherical pores
• X-Ray Diffraction after LMD
• Mainly a hexagonal phase (+ bcc b in vertical oriented part)
• High crystallographic texture:
<-12-10> preferentially along build direction and <0001> // scanning directions
• Elongated prior b grains along build direction after LMD
Build direction Z Scan direction X Scan direction Y
Acknowledgement Research funded by SBO Project grant 110070: eSHM with AM of the Agency for Innovation by Science and Technology (IWT)
2h 950C, AC 2h 850C, FC
Z
Effect of machining & HT sequence Effect of loading orientation & HT
Crack growth during four point bending
Horizontal
• Relatively strong & ductile material behavior for vertical oriented part
• Heat treatments lower the strength & increase the elongation
• 850C: fine Widmanstätten α+β with discontinuous β phase; grain boundary α
• 950C: coarse Widmanstätten α+β structure with grain boundary α in columnar structure
Milling is preferred above EDM
EDM + HT: harder, more brittle surface layer (~ 440-470 HV ↔ 360 HV in centre)
Corner notch
Bottom
Side
• Crack initiation (@ 17.8 kN, 16 kN and 14.4 kN)
~ 4,5 times faster for LMD sample compared to conventional Ti6Al4V
• Crack propagation (@ 13kN)
~ 3 times faster for LMD sample compared to conventional Ti6Al4V
+ EDM HT@950C
Vertical - Top
Z
