Wire plus laser AM Hybrid wire plus arc

Wire plus laser AM & Hybrid wire plus arc AM Gonçalo Pardal 31 -05 -2018 www. cranfield. ac. uk

Outline: Wire plus laser AM Hybrid wire plus arc AM • • Goal and objectives Introduction Experimental setup Results • WLAAM multi layer sample • Conclusions Goal and objectives Introduction Experimental setup Results Hybrid laser-CMT bead on plate deposition Hybrid laser-CMT WAAM deposition • Conclusions 2

Wire plus laser AM Goal and objectives: Goal: • Investigate if WLAM (Wire plus Laser Additive Manufacturing) can produce final shape components. Objectives: • Develop a deposition setup. • Study single and multi layer deposition. • Build AM walls to test the conditions. 3

Introduction WAAM - Wire and Arc Additive Manufacturing AM technique being researched at Cranfield University for the past 10 years. It uses common welding techniques (MIG, plasma welding) and wire as feedstock. Plasma welding torch Welding arc Wire feeder Welding wire Deposited layers Substrate 4

Introduction WAAM - Wire and Arc Additive manufacturing The parts are built layer by layer and net shape is achieved. This need to be machined to achieve the final component (between 0. 5 mm to 2 mm). Deposition rate in Ti between 400 g/h to 1. 2 Kg/h WAAM can be used to build complex metallic parts. 5

Introduction WLAM: Wire and Laser Additive Manufacturing As a complementary AM technique WLAM was investigated. LASER: Flexibility in beam manipulation Small and controlable beam diameter Higher processing speeds Laser beam Wire WLAAM Wall Weld pool Substrate 6

Experimental set-up q SPI Fibre laser of 3 k. W q Ar inert atmosphere q Wire diamter 0. 6 mm Laser head Flexible Argon enclosure Linear stages 7

WLAM multi layer sample • Deposition rates are complimentary to WAAM (200 g/h to 400 g/h). • Layer heights are up 10 times smaller than WAAM. • Low surface waviness no finishing machining needed (final shape obtained). Final shape deposition 8

Conclusions • WLAM is a viable process to build AM components. • It can build very small components in final shape condition, avoiding extra steps to finish the part. • The high focus ability of laser generates small weld pools making the wire feeding a very important factor. 9

Hybrid wire plus arc AM Goal: • Investigate how laser in conduction mode can be used to stabilize MIG WAAM deposition and increase the deposition rate of Ti-6 Al-4 V parts. Objectives: • Use a defocused high power laser to stabilize and/or modify the weld bead shape of MIG Ti-6 Al 4 V deposition. • Increase the deposition rate of Ti-6 Al-4 V when compared PTA (Plasma Transferred Arc) WAAM deposition. 10

Introduction Ti WAAM: MIG AM wall: Plasma AM wall 11

Experimental setup – Hybrid laser-CMT bead on plate deposition Laser head Ti-6 Al-4 V Welding wire MIG welding torch Trailing shield Laser beam Bead on plate weld The wire feed speed was fixed at 9 m/min and the laser power was varied 12

Results – Hybrid laser-CMT bead on plate deposition CMT Hybrid laser-CMT roots the cathode spot, stopping the arc wandering. This translates to better control in the deposition and better 3 D printed parts. 13

Results – Hybrid laser-CMT bead on plate deposition CMT Hybrid laser-CMT Hybrid laser reduces the wandering of the arc and the weld bead waviness. Laser increases the deposition rate of the process form 1. 5 kg/h to 2. 0 kg/h (33% increase). Hybrid laser-CMT increases the deposition rate of Ti by 66. 6% when compared to plasma deposition process. 14

Results – Hybrid laser-CMT WAAM deposition Effective wall width of 2. 98 mm (CMT) vs 5. 93 mm (Hybrid laser-CMT), increasing the effective deposition. Average layer height decreases, introducing better resolution to the hybrid laser-CMT WAAM process. CMT microstructure more equiaxed when compared to the hybrid process (Higher heat input). Sample 25 CMT WFS/TS = 18 Sample 26 Hybrid laser-CMT WFS/TS = 18 Laser Power = 2500 W 15

Conclusions • Hybrid laser-CMT can stabilize the arc wandering phenomenon and change the typical weld bead shape of with Ti CMT deposition. • It can generate straight single bead and wall depositions. • Hybrid laser CMT can increase the Ti deposition rate to 2 kg/h, increasing also the WAAM process efficiency without sacrificing its resolution. 16

NEWAM • Building in the research presented here Cranfield won a new Wire based AM programme grant. • EPSRC Programme grant ~£ 6 M + £ 3 M industry support = £ 9 M • Programme duration 5 years • Programme start date June 25 th 2018 • Main goal: To develop new innovative high build rate metal wire AM processes and systems for net shape deposition at low cost over large volumes with homogeneous microstructure and properties – target 8 kg/hr net shape for Ti. 17

Thank you for listening Any questions? 18