Feb 24, 2015

Laser metal deposition five axis 3d printing for aerospace appliances by Merlin Project

Laser metal deposition (LMD) is DMLS process that is the future of aerospace industry. Since European Union is a manufacturing powerhouse it is investing in many R&D projects like Merlin.
Ever major technological power is in the race to rule the industry and advance in digital manufacturing age.

From project description:
A 5 axis laser metal deposition manufacturing method is being developed by TWI for an EU-funded project which is demonstrating drastic time reduction in the manufacture of aero engine casings. 
In LMD, a weld track is formed using metal powder as a filler material which is fed through a coaxial nozzle, to a melt pool created by a focused high-power laser beam.
By traversing both the nozzle and laser, a new material layer develops with precise accuracy and user-defined properties. The application of multi-layering techniques allows 3D structures to be created.
To find out more please visit the project website: http://www.merlin-project.eu/ or go to TWI's website:http://www.twi-global.com/news-events...

Here is a video of the process. It took seven and half hours to print this thin walled casing prototype for jet engine test beds.

Here is a list of LMD technical advantages and disadvantages:

Advantages of LMD:
  • Metallurgical bond (not mechanical, thermal spray)
  • Wide variety of available powders 
  • Very low dilution is possible 
  • Relatively high deposition rates 
  • Process is highly repeatable 
  • Low impact on base material compared to similar processes (HAZ) 
  • Superior metallurgy compared to similar processes 
  • Virtually unlimited build height 
  • Very flexible tool path compared to wire applications 
Disadvantages of LMD:
  • High capital equipment costs
  • Powder cost is typically higher than wire
  • Capture ratio of additive material < 100% (based on process parameters)
  • Cannot control the process manually – CNC is required 
  • Experienced, specialized staff required (e.g. laser safety engineer, skilled operators)
LMD laser toolhead schematics: