1. Additive Manufacturing Using Laser Applied Powder® Processes
AWS New Welding Technologies
June , 2010
Salay Stannard
A brief overview and lessons learned from the LAP® processes including hard facing, corrosion-resistant coatings, worn surface restoration to laser applied manufacturing  (LAM) of components. Discussion will also include focus on equipment capabilities as related to various industries such as aerospace, medical, oil and gas exploration, mining, power generation and industrial equipment repair.
Cladding and
Additive Manufacturing Using
Laser Applied Powder® Processes

2. Who Is Joining Technologies?
About 60 employees
25,000 SF, With Room to Expand At Current Location
2,000 SF Dedicated to Laser Cladding
Laser Applied Wire (LAW®) Additive Processing
Laser Applied Powder (LAP®) Additive Processing
Laser Welding
EB Welding
GTAW
Lasers Systems Design & Integration
Supply Chain Management
ISO 9001:2000
AS9100
NADCAP Certified for Welding
Who Is Joining Technologies?

3. The Necessity for Component Repair and Surfacing Technologies
Why repair technologies are needed:
Wear and Damage
Sealing Surfaces
Mounting / Fretting Surfaces
Bearing and Loaded Surfaces
Tools and Dies
Manufacturing Nonconformities
Under filled castings
Incorrect Machining
Design Changes
High Value Parts
Long Lead Times
Simple truth: component wear out and either need replacement or repair.
Cladding and additive manufacturing offer repair solutions for worn surfaces
Mounting / fretting surfaces
Bearing and loaded surfaces
Servicing tools and dies need in turn need restoration
Often there are manufacturing nonconformities that require attention
These come in the form of under filled castings
Incorrect machining and design changes
Each of the components we are talking of are high value parts that have extraordinarily long lead times for replacement, the solution is to perform a cladding operation to place the component back into service sooner.

4. Laser Based Repair Technologies
Pulsed Wire Cladding
CW Laser Wire Cladding
Laser Blown Powder Cladding
The three methods of additive that I will be addressing are
Pulsed Wire Cladding
CW Laser Wire Cladding
And Laser Blown Powder Cladding
So, a brief introduction as to what each are for those in the audience that are not familiar with cladding:

5. Pulsed Laser Wire Cladding
Wire is positioned on top of substrate
Wire is stationary relative to part
Laser fuses wire to substrate by a series of spot welds
Manual or automated processing
Manual process is well suited to limited production or highly irregular repairs
Not well suited to crack sensitive materials due to rapid heating and cooling rates
Low deposition rates due to low average laser power, limited pulse rate and need to synchronize wire and part feed
Pulsed Laser Wire Cladding is an operation by which wire is position on top of the substrate while a series of laser spots welds are used to fuse base material and wire together.
The process is completed in either an automated or manual method, the manual method being more suited for the limited production or high irregular repairs
Wire cladding is not well suited to crack sensitive materials due to the rapid heating and cooling rates
And low deposition rates due to low average laser power, limited pulse rate and the need to synchronize the wire and part feeds

6. Continuous Wave (CW) Laser Wire Cladding
Laser beam creates molten pool on part
Filler wire is fed into pool by precision wire feed
Wire is melted and incorporated into the pool to create a bead
Process is nearly always automated
Better for crack sensitive materials
~10x higher deposition rates than pulsed wire
CW Laser Wire Cladding like pulsed utilizes the laser beam to create a molten pool on the substrate into which filler wire is precision fed into the pool. The wire is thus melted and metallurgically fused to the part.
The process is nearly always automated and better for crack sensitive materials
In turn CW Laser Wire Cladding produces approximately 10X higher deposition rated than pulsed operations

7. Laser Powder Cladding Laser beam creates molten pool on part
Metal powder is blown into pool
by precision powder feed system
Powder is melted and
incorporated into the pool to
create a bead
Process is always automated
Largest selection of available clad materials
~10x higher deposition rates than
CW wire feeding
Finally Laser Powder Cladding uses the laser source to create a molten pool on the component into which metal powder is blown by a precision powder feed. The powder is melted and incorporated into the pool to create a bead.
This method of cladding is always automated and benefits from the largest selection of clad materials
Additionally, Laser Powder Cladding has approximately 10X higher deposition rates than CW wire feeding

8. Blown Powder Nozzle Schematic
Laser Powder Cladding
Blown Powder Nozzle Schematic
Multijet Nozzle
Coaxial Nozzle
Here we can see how metal powder is incorporated into the laser puddle and fused to the component.
This is accomplished using either a multijet or coaxial nozzle.
The multijet has three discret streams of powder while the coaxial nozzle employs a full cone of blown powder. Generally speaking the coaxial nozzle is better suited for detail and fine depositions.

9. Need for Cladding and Additive Manufacture
Aerospace
Power Generation
Oil/Gas
Now that we’ve discussed the foundation of cladding and additive who has the need?
From the experience of Joining Technologies we’ve found a lot of the repair and restoration needs come from Aerospace, Power Generation and the Oil and Gas Industries.

10. Special Challenges in Aerospace Processing
Need: Overhaul and Repair
Process: Limited industry specifications
FAA & OEM barriers
Limited to repair and design work
Document/Control
Stringent metallurgical requirements
Minimal heat input required
Poor capture rate: 30-40% detail, 12-20% knife edges
Machine cannot be modified after source approval
Test pieces are rare due to high cost of part
Aerospace components are primarily in need of overhaul and repair.
In our experience there are a lot of challenges associated with aerospace processing. These are largely due to the limited industry specifications and barriers from the FAA & OEMs. Each want to know what spec you are welding to? Is it D17.1? Does it fall under any AWS qualification? They are very concerned with DERs. The one exception will be blade tip repairs that have been accepted under Huffman.
Because of this any work for cladding will be restricted to design and repair work. Be aware that like all that surrounds the aerospace industry your cladding repairs must be well documented and controlled. There will be stringent metallurgical requirements in which distortion and the amount of heat input must be minimal. Typically the powder efficiency or powder rate will be low, 30-40% for detail work and what we’ve found as 12-20% for knife edge repairs.
You’re work cell cannot be modified after source approval
And test pieces will be rare due to their high associated costs – coupon work will be necessary

11. Special Challenges in Power Generation
Need: Hard facing,
corrosion resistance
Longer processing times
for large part surface areas
JT: 9.6lb/hr approx 90% capture
Part geometry varies job to job
Less stringent on powder quality
Open metallurgy requirements
Accepting of ↑HAZ, dilution, etc.
Power generation components need hard facing and corrosion resistance.
Biggest associated hurdle will be the long processing times for the surface area that must be covered. Best way to overcome this is to develop your processing parameters. Joining Tech has been able to obtain a 9.6lb/hr cladding at 90% capture, again largely dependent on feeds, speeds, parameter settings.
You will find that that part geometry varies greatly from job to job- one job will be valve work and the next could be a flat surface.
What is nice about cladding for power generation components is they are more open on metallurgy, accepting of increased HAZ, dilution, porosity, etc.

12. Special Challenges in Oil/Gas
Need: Hard facing,
corrosion resistance,
wear resistance
Longer processing times
for large part surface areas
Less stringent on powder quality
Accepting of ↑HAZ, dilution, etc.
Like Power Generation, the Oil and Gas components need hard facing, corrosion resistance and also wear resistance
The same challenges will be encountered here for longer processing times while there are benefits of open powder and metallurgy quality.

13. Work Cell for Aerospace Processing
Platform:
Cartesian CNC preferred
Beam quality is important
Solid-state systems -Disk or fibre lasers
JT: 2kW → 4kW Trumpf disk laser
Clad Requirements:
Powder- Rotary vs. Atomized
Quality is critical!
Accepting of additive with wire
Typical repair thickness < 0.060”
Materials deposited include:
Stellite 6, 21
SS410, 410L
IN 100
If you aren’t deterred by these hurdles then lets discuss what type of work cell is preferred for each.
Aerospace processing will benefit the most from a Cartesian CNC platform. May ask why not use robotics? You will need real time calculation and distribution of moments or loading between each axis for the high precision work of aerospace repair. The tool path accuracy CNC surpasses that of a robotic system.
Beam quality is very important for that detail repair and so you can venture into using disk or fiber lasers, each provide better focusability! , 2kW of power will be sufficient
In terms of the clad powder itself the quality is very important. Each can be manufactured as rotary or atomized powder. Better quality comes from atomized, but you will pay the price per pound. If you can stick to repair processes using wire as the aerospace industry is more accepting of this method. The typical repair thickness will be above 0.060”
Materials deposited can include:
Inconel 625, 718
4047

14. Work Cell for Power Generation Processing
Platform:
Flexible beam quality,
direct diode systems possible
3 -7mm spot size
Coaxial system, He powder delivery
Clad requirements:
Typical thickness 0.040” – 0.200”
JT: deposited 0.040” – 3+”
30-60 HRc, > 45 HRc cracking possible with carbide powders
Materials deposited include:
Inconel 622, 625, 718
Carbides
Since the power generation industry is less stringent on quality of the clad you can be more flexible in terms of beam quality, this means direct diode systems are possibilities. Typically deposition will be between 3-7mm spot size and you will want to use a coaxial system with helium powder delivery
Clad requirements:
Materials deposited:
Stellite 6, 21
Ni-Cr
Tool Steels

15. Work Cell for Oil/Gas Processing
Platform:
Flexible beam quality, direct diode
systems possible
3 -7mm spot size
Coaxial system, He powder delivery
Clad requirements:
Typical thicknesses 0.040” – 2”
> 0.080” cracking possible
Materials deposited include:
Carbides
Ni-Cr
Inconel 622, 625, 718
Stellite 6, 21
Like power generation, oil and gas processing is not restricted by quality and neither will your beam.
Clad requirements:
Materials deposited can include:
WC-Cr
WC-Co-Cr

16. Advantages of Powder vs. Wire
Laser Wire Cladding
Welding with wire is a well established aerospace process
Typically lower capital investment than for powder
Crack and pore free deposition is attainable for many common aerospace materials using commercially available wire
100% utilization of filler material
So you may now be wondering what do I choose, wire or powder?
Laser wire cladding is a well established aerospace process….
Conversely, laser powder cladding has higher maximums for deposition rates….
Laser Powder Cladding:
Higher maximum deposition rates
Larger variety of possible clad materials
Processing head is compact, omnidirectional and completely non contact
Minimum feature size and heat input are limited only by minimum laser focus size and economics
Lower dilution

17. Joining Technologies Laser Additive Systems
LAW ® Work Cell Equipment
Designed and built by Joining Technologies
Trumpf TruDisk 1000 Laser supply
3- Axis CNC control with rotary
Wire 0.010” – 0.025” diameter
Closed loop servo controlled wire feed
Real time power density control while welding
Non contact profile scanning with data storage
Highly efficient wire placement algorithms
Vision based wire tracking within 0.003”
Real time work piece temperature control
At Joining Technologies we started additive processing with a completely home built system coined the LAW, or Laser Applied Wire. It is a Trumpf TruDisk 1000 (1kW) system with….

18. Joining Technologies Laser Additive Systems
LAP ® Work Cell Equipment
Trumpf TruDisk 4002 (4kW) Laser Supply
KUKA KR 30/HA (High Accuracy) Robot
Approx. 6ft radius hemisphere range
66lbs. payload
KUKA DKP Rotary/Tilt Table
Approx. 880lbs. load
Programmable Dual Powder Feeders
On the Fly Focus spot size control
Multi-jet or Coaxial powder delivery
We like additive and cladding so much we then expanding to powder with the LAP or Laser Applied Powder platform. Started with a 2kW laser supply and recently upgrade to a Trumpf TruDisk 4002 (4kW) supply. Utilizing a KUKA KR 30 high accuracy robot with approximately….

19. Joining Technologies Laser Additive Systems
Equipment Acquisition
August installation of Trumpf 505 Powder Cladding system
6kW CO2 Laser
6.5ft X 3.2ft X 2.5ft envelope
5 Axis motion platform
High capacity rotary
Programmable spot size
High absolute and relative accuracy
Two hopper powder feed
Joining Technologies is happy to announce that we are expanding our cladding capabilities with the acquisition of ….

20. Joining Technologies Laser Additive Systems
Lab Expansion and LAP ® Upgrade
Additional 10,000 sq ft cladding workspace
Accommodations for parts up to
3ft dia x 40ft long x 5 tons
30ft linear rail for robot positioning
Multi-ton capacity precision head stock,
tail stock and steady rests
To complement our new acquisition we are upgrading our lab for an additional 10,000 sq ft of workspace….

21. Conclusions
Both laser additive technologies, wire and powder, have many overhaul and repair applications for the aerospace, power generation, and oil/gas industries.
When compared to traditional repair processes additive manufacturing maintains base metallurgy with low heat inputs and a high degree of control.
Industry acceptance remains a challenge, but is sure to improve with continued research, development and testing.
In conclusion we have found that both laser additive technologies, ….

22. Thank You!
Salay Stannard Process Development Engineer
Scott Poeppel Manager of Additive Processes
Dave Hudson President
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Thank you again for inviting us and I’ll now take some time to try and answer any questions you may have about cladding or Joining Technologies….