Technical Site Visit to IRIS
New Laser for Direct Metal Deposition

Date : Tuesday, 17 July 2007
Venue : Industrial Research Institute Swinburne
Swinburne University of Technology
533-545 Burwood Road, Hawthorn, VIC 3122

This function was organised jointly with Materials Australia and hosted by Prof. Milan Brandt.  It took the form of a brief presentation, addressing the evolution of direct metal deposition (DMD), the current state of the art and various potential applications, followed by a demonstration of the process.

The opening presentation addressed the topic of Art to Part by DMD, or how to build a pyramid directly from metal powder.

Pyramid Fabricated by Direct Metal Deposition

Fabrication of three-dimensional shapes with engineering materials has been of considerable interest for the past few decades.  Early developments were in the area of rapid prototyping with photopolymer and laser sintering of polymer and metal powders.  During the past decade several laboratories throughout the world have made tremendous progress in producing functional metallic parts directly from Computer-Aided Drawings (CAD).  The technology is based on the laser cladding process.  In laser cladding, the beam from a high-power laser creates a melt pool on the surface of a solid substrate into which a metallic alloy powder is injected.  The laser melts the powder and fuses it to the substrate creating a fully dense, metallurgically sound bead.  The width of a single bead depends on the diameter of the laser spot on the surface and is normally in the range 0.6 5 mm.  By overlapping the beads, usually by 50%, a continuous layer is produced.  The properties of the fabricated part are very much dependent on the operating conditions, laser power, speed of processing, powder mass flow rate, powder particle size and size of the laser spot used.  By combining this technology with a 5-axis laser beam delivery system and a feedback control system it is possible to produce fully functional 3-dimensional components.  IRIS has recently acquired a POM direct metal deposition (DMD) system for fabrication, restoration and reconfiguration of components.