Then and now

Several widely promoted applications, very high power (10 kW+) thick-section fiber laser cutting and laser cutting underwater, prompted me to recall that I have been involved in the field of high-energy density material processing for a long time, as these were ‘goes around comes around’ processes. Actually, I’ve been involved for a very long time, as I will celebrate 50 years in industrial laser material processing next year. And prior to this, I also had seven years in electron beam welding. My laser background was entwined with that of laser weapons, which were brought back to mind in a recently published, very readable book written by friend and associate Jeff Hecht—Lasers, Death Rays, and the Long Strange Quest for the Ultimate Weapon (Prometheus Books).

Back then, as a member of the Research Staff at Raytheon Company, I was part of a ceramic engineering group charged with growing ruby crystals to make the rods for high-output-power solid-state lasers, in a company bid for substantive government funding. Jeff covers this laser development period nicely in his book, although he passes on this early Raytheon effort. But he does mention how material processing lasers, those I eventually worked with, were at one point considered as an alternative to unproven new laser technology.

Jeff also discusses a then-secret, high-energy laser that was being tested in a lab adjacent to the industrial high-power CO₂ application lab when I was Director of Applications at Avco Everett Metalworking Lasers. Every time they fired off a pulse, it was followed by a giant blow-down of byproducts that prompted its then-secret name—Thumper. Industrial Laser Solutions Editorial Advisor Stan Ream, who was our applications engineer then, today still remembers that “It used to scare the c..p out of us and dust fell off the walls.” These gases were sucked up by our air conditioners and fed into our laser enclosures, where they caused the CO2 laser beam to ‘blossom’ and lose focus right in the middle of a process. This generated consternation among visiting manufacturing engineers and there was always a lot of excuses as the ambient air cleared. We alibied answers to questions about it from our potential customers, many of whom returned to their industrial companies with tales of the secret laser experiments they had overheard.

Well, that was then and this is now. It’s 2019, and the more-than $5 billion laser industry continues to deliver advanced laser solutions to today’s processing problems. A qualified group of authors has contributed feature articles on current hot topics: additive manufacturing, joining plastics to metals, controllable beam shaping, and black marking of medical devices.

Ahmed Maamoun (McMaster University) addresses concerns with expensive cost and the fabricated part’s quality in additive manufacturing aluminum parts by sharing his research on solutions to some related challenges by using recycled aluminum powder and how process maps can be generated for additive manufacturing and post-processing treatments to achieve desired quality (see page 14).

Companies in Eastern Europe may find this useful, as Evgeny Molchanov (Rena Solutions) reports that laser additive manufacturing is in a catchup mode because user companies there are slowly finding cost-effective solutions (see page 24).

Perhaps hotter in Europe than in the U.S. is laser joining plastics to metals. Annett Klotzbach and peers (Fraunhofer IWS) have achieved self-defined goals of developing productive solutions for direct and form-fit joining (see page 18).

And Europe also seems to be leading the charge with adaptive beam shaping to simultaneously improve laser drilling process results, writes Sami Laroui (CAILabs; see page 22).