3D laser printing of Hydroxyapatite by SLS/M L. Ferrage 1S , D. Grossin 1S , B. Ben-Nissan 2 , M. Healey 3 , M. Perez 3 2: 3: 1: S: Secondment - NEXT-3D Mid-term meeting, Brussels, Nov 24 th 2016 - 1 SLS/M HAP What phenomena are significant in SLS/M ? 1) Flowability of powder Mobility from “powder supply” to “build platform” using Recoater arm. (grain size, shape … ) 2) Laser-powder Interaction Powder need to be melted or sintered (thermal properties of material, grain size, laser-mater interaction … ) 2 1
SLS/M HAP Laser interaction 1) 2) Selected sintered area sintering 3) 4) 3 SLS/M HAP No interaction With hydroxyapatite and standard configuration Laser Material spherical Or decomposition Strong support interaction 4 2
SLS/M HAP How to increase absorption of Powder and decrease absorption of support ? absorption absorption absorption - Ø + - T + - Ø + Absorption VS wavelength Absorption VS Temperature Absorption VS grain size 5 SLS/M HAP How to increase absorption of powder ? Core Material Reactive shell Doping Core-shell Nanostructuration Process l abs P ower T (Préheating) Laser Support 6 3
SLS/M HAP • Using different machines/lasers in order to sinter ceramics Oxides 7 SLS/M HAP SLS of Ceramic EOS M250 XT – Laser CO 2 Laser wavelength (CO 2 ) : 10,6 µm Power max: 240 W Scanning speed: 50-5000 mm/s BresMedical Ltd. Support : Titanium or Stainless steel 8 4
SLS/M HAP Hydroxyapatite powder Ca 10 (PO 4 ) 6 (OH) 2 50 µm < d particules < 160 µm 9 SLS/M HAP Parameters: - Puissance laser - Scan speed - Layer Thickness - Hatch Distance - Lasing patterning - Support (Yes/No) - Multi-lasing (Yes/No) - Material (Powder/Support) 10 5
SLS/M HAP • Movie 11 SLS/M HAP Parameters : TA6V support [O 2 ] gaz < 1,5 % Support Temperature = 80ºC Strategy « external supports » Layer Thickness = 100 µm Power = 85, 90 or 95% (204 à 228 W) Scan speed = 80 or 100 mm/s 12 6
SLS/M HAP External supports ? Lattice structures supports Decrease support absorption IP protections action(s) 13 SLS/M HAP XRD powder: 20000 15000 Poudre Teknimed 10000 5000 0 10 20 30 40 50 60 70 80 90 2 Theta 14 7
SLS/M HAP XRD sintered pellets: [best match = Ca 4 (PO 4 ) 2 O] 15 SLS/M HAP Analyse Raman : (633nm) UTS 16 16 8
SLS/M HAP Analyse FTIR : (ATR) UTS 17 17 SLS/M HAP Top surface (Optical): 18 9
SLS/M HAP SEM, Top surface : 19 19 SLS/M HAP SEM, Fracture surfaces : 20 10
SLS/M HAP Conclusion : 1 st SLS samples of HAP without doping Wavelength (CO 2 )= 10.6 µm Strategy « external supports » IP protection action Optimization is required 1 Review article on 3DP of Ceramics 21 11
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