sponsored by ALD Vacuum Technologies...

Laurenz Plöchl, Inert Gas Atomization for Metal Additive Manufacturing Powder Production May 19-21, 2014 • Hilton Sorrento Palace, Sorrento, Italy

Session I: “3D Ti – Additive Manufacturing” sponsored by ALD Vacuum Technologies GmbH

1


Session I: “3D Ti – Additive Manufacturing” sponsored by ALD Vacuum Technologies GmbH

14:00 - 14:15 Inert Gas Atomization for Metal-AM Powder Production

Laurenz Ploechl ALD Vacuum Technologies GmbH

14:15 - 14:30 Ti based Powders Supply Chain for Industrial Additive Manufacture

Paolo Gennaro GE-Avioaero

14:30 - 14:45 The Use of Metal Powders in Additive Manufacturing, a View into the Associated Machine Technology

Hendrik Schonefeld SLM-Solutions

14:45 - 15:00 Minimizing Contamination in Titanium Gas Atomization

Eric Bono Summit Materials, LLC

15:00 - 15:15 Q & A

2


Inert Gas Atomization for Metal Additive Manufacturing Powder

Production

3


Irregular vs. Spherical Metal Powder Inert gas atomized powder exhibits always spherical particle shape, whereas metal powder out of alternative production processes (e.g. chemical precipitation, HDH, crushed, ball-milled, etc.) exhibits irregular particle shape.

Powder flowability: good Compactability in uni-axial powder press: poor

Powder processing consequences of spherical powder:

• Consolidation into a PM-semifinished product is more costly with spherical powder, because compaction usually not by simple uni-axial press

• Multiaxial compaction processes (HIP, hot extrusion) are required. This is acceptable where no alternative powders are available (e.g. high-speed steel, Ni-base superalloys, titanium, specialty materials, precious metals)

For novel near-net shape processes (such as MIM, AM) as well as for thermal spray and for shaped-HIP-parts, the spherical powder particle shape is a desired feature due to the better powder flowability

Ti-powder, HDH (source: Ivasishin et.al.)

Ti-power, EIGA (inert gas atomized)

4


Inert Gas Atomization Vacuum Induction-melting with or without Ceramic Liner

VIGA EIGA

VIGA Vacuum Induction Melting Inert Gas Atomization EIGA Electrode Induction Melting Inert Gas Atomization

ALD has the capability to combine various vacuum melting technologies with inert gas atomization, which enables the production of superclean metal powders, such as superalloy, titanium, γ-TiAl, zirconium and precious metal powders for Metal Additive Manufacturing (and other consolidation techniques).

5


Applications: …where high-cleanliness, spherical metal powder is required, such as:

VIGA Metal Additive Manufacturing Applications/Alloys: PBF (Powder Bed Fusion) and DED (Directed Energy Deposition) Typical Alloys: high-alloy steels, In625, In718, In738, CoCr, precious metal alloys

EIGA Metal Additive Manufacturing Applications/Alloys:

PBF (Powder Bed Fusion) and DED (Directed Energy Deposition) Typical Alloys: TiAl6V4, γ-TiAl, Zr702, precious metal alloys

SLM In718 turbine blade (courtesy of SLM Solutions) EIGA TiAl6V4 powder (courtesy of HZG)

6


VIGA/EIGA Process Data

7


EIGA Process Fundamentals

EIGA atomization of CP-Ti 100mm Ingot (courtesy of HZG)

EIGA atomization of gamma-TiAl 60mm Ingot (courtesy of HZG)

An alloy barstick is fed at constant speed vertically from the top into a conical induction coil A high-frequency electromagnetic field induces Eddy-currents in the barstick which starts to form

a melt film at the conical surface The melt film flows to the cone tip and melt drops separate. A constant melt flow evolves after

start-up and flows vertically into the inert gas nozzle The process enables melting and inert gas atomizing of refractory and/or reactive alloys without

a ceramic liner or cold wall

8


EIGA Process Modelling

ALD has a 3D FEM-model of the standard EIGA coil and cylindrical barstick with conical tip. With this model, we can compute total power induced into barstick [kW], power density in barstick [W/m3],

inductivity [µH] and ohmic resistance [mΩ] of coil-barstick arrangement. Model parameters are feedstock metal, coil current, frequency, barstick cone diameter and cone angle,

barstick immersion into coil

9


EIGA for Large-Scale Ti Powder Production

Barstick diameter: max. ∅ 50mm max. ∅ 100mm

Barstick length: 500 - 1000 mm max. 1000 mm

Batch weight (Ti): 5 – 10 kg 35 kg

Atomization rate (Ti): max. 0.5 kg/min max. 1 – 1.5 kg/min

Batch cycle time: approx. 15 min approx. 45 min

Ar gas flow rate: 8 - 18 m3/min STP 8 – 18 m3/min STP

Nominal power: 60 kW 250 kW

Powder output p.a. max. 70 MT max. 250 MT

CAPEX 1.0 Mio. EUR 1.5 Mio. EUR

EIGA 50-500 (standard type)

EIGA 100-1000 („Large EIGA“ prototype)

10


EIGA Benchmark with other ceramic-free atomization processes PREP (Plasma Rotating Electrode Process)

CICAP (Cold-wall Induction Crucible Atomization Process)

ICPS (Inductively-coupled Plasma Spheroidization)

sour

ce: A

PC w

ebsit

e

sour

ce: I

.E-A

nder

son

et.a

l.

sour

ce: S

uper

allo

ys,

M.J.

Dona

chie

.

sour

ce: T

ekna

web

site

+ Flexible alloy and feedstock options including possibility to melt in revert material (scrap, chips)

+ Reasonable fine powder yield

− High energy consumption − Complex machine and process − Safety concerns about potential

water leakage − Ceramic orifice as potential

contamination source − Frequent orifice clogging − Possibility of Ar pores in coarse

particles − Relatively high Ar flow rate

(internal recycling possible)

+ Relatively low Ar flow rate (internal recycling possible)


− Relatively high energy consumption

− Less flexible alloy and feedstock options (subject to availabilty of alloy powder)

− Exclusive, proprietary process − Possibility of Ar pores in

coarse particles − Low throughput

+ Low CAPEX + Proven, robust, simple, safe

and economic process + Relatively low energy

consumption + Reasonable fine powder yield + Commercially available plant

and process (by ALD) + Flexible alloy and feedstock

options (cast barstick from CIC, EB or PH furnace or VAR ingot), including possibility to melt in revert material (scrap, chips)

− Possibility of Ar pores in coarse particles

− Relatively high Ar flow rate (internal recycling possible)


− Expensive feedstock (thin Ti wire)

− Less flexible alloy and feedstock options (subject to availabilty of thin wire)

− Exclusive, proprietary process − Possibility of Ar pores in

coarse particles − Possibility of tungsten spitting

off plasma torch electrodes − Today no commercial vendor

of PWAP plant

+ Narrow PSD + No or less Ar pores + Relatively low Ar flow

rate (internal recycling possible)


− Not 100% liquid (slushy) before atomization (anisotropic particles)

− Expensive feedstock (precision-machined ingot)

− Low fine powder yield − Possibility of tungsten

spitting off plasma torch electrodes

− Today no commercial vendor of PREP plant

+ Relatively low Ar flow rate (internal recycling possible)


PWAP (Plasma Wire Atomization Process)

EIGA (Electrode Induction-melt Inert Gas Atomization)

11


Thank you for your attention!

12

sponsored by ALD Vacuum Technologies...

Documents

Transcript of sponsored by ALD Vacuum Technologies...