Overview of Laser Additive Manufacturing

By Professor Bill Steen

From the early beginnings of LAM has come a process which is developing in many directions. Through the variety of ways in which the laser can construct three dimensional objects it has been established that designers can now shape both the outside and the inside of a casting in detail not previously possible. It has also been found that LAM can be used as a hybrid technique by building on preforms to speed up production. It is a subject bristling with opportunities. The current ideas under development include new techniques for forming clad layers by supersonic forge bonding for cold weld build of heat sensitive structures or structures on heat sensitive substrates; new materials can be deposited by blown powder laser cladding to form unusual clad layers such as graded layers, or forming alloys in-situ by blowing a powder mix of the alloy ingredients; a new scale of build is now possible from large to submicron, particularly using 2 photon polymerisation instead of the usual 1 photon process in stereolithography; new structures with crafted internal design to give strength and light weight are being actively researched, some to simulate the structure of bones others for lightweight aircraft parts. New applications might include the development of hand held cladding systems for the artist craftsperson or adaptive controlled cladding for the in-situ repair of large turbines; personalised prosthesis of teeth or bones can be made for the medical community. The subject has so much promise there should be something for everyone! But do we have the engineers fluent enough in the application of optical energy to take advantage of what is on offer when there are so very few university departments of optical engineering?