Joining technologies: where to go from here not to be left behind?

Citation

Messler, R.W. (2000), "Joining technologies: where to go from here not to be left behind?", Assembly Automation, Vol. 20 No. 2. https://doi.org/10.1108/aa.2000.03320baa.002

Joining technologies: where to go from here not to be left behind?

Joining technologies: where to go from here not to be left behind?

Robert W. Messler

Keywords: Joining, Adhesives, Welding, Fastners

As we enter the new millennium, three things are certain:

1. 1.

   death;

2. 2.

   taxes; and

3. 3.

   that technology will continue to change and advance at an ever-increasing rate.

While much of that technology surely will relate to our ability to find, create, communicate, and process information, not all of it will. There will also be new technologies in transportation, energy generation and transformation, medicine, recreation, construction, and virtually every other aspect of our lives. Since all of these either rely on physical entities composed of materials directly (e.g. lighter, stronger materials for automobiles and aircraft; super-conducting materials for energy generation or transformation; more biocompatible materials for medical prosthetics; stiffer, more energy-absorbing materials for golf clubs and tennis rackets; stronger, lighter, more insulating materials for home and building construction) or indirectly (e.g. super-magnetic materials and optical materials for information storage and transport), the ability to join materials of increasing diversity, increasing specific functionality, and of smaller and smaller (for information processing) as well as larger and larger (for construction) dimensions, will not abate, but will accelerate. For these reasons, we need to think now - and be ever mindful - of what it will take and where we need to go so that joining technologies are not left behind.

Just to set the record straight, there is some cause for concern. A strong case can be made that despite dramatic and impressive advances over the course of the just-completed millennium, there are examples where the ability to join materials and structures has either not kept pace with advances in materials, or less-than-optimal, stop-gap solutions have been employed (Messler, 1996). While resourcefulness for remediation of problems is an admirable quality in engineers, as opposed to careful forethought and thorough understanding to allow the best answer to be obtained, it can ultimately impede progress, limit performance, and/or add cost. Let's look at the record for a moment.

First and foremost, in reality, virtually every fundamental method for joining materials and structures existed before we entered the just-passed millennium! Think about it. Mechanical attachment and fastening, welding, brazing, soldering, and adhesive bonding; they all existed! Ancient civilizations, pre-dating the First Millennium A.D., either invented or inherited solid-state (or nonfusion) forge welding, brazing and soldering of metals, fusion welding (or, simply, fusion) of glasses, sinter bonding and reaction bonding of ceramics, and mechanical joining using fasteners (e.g. at least pegs and nails and rivets) or integral attachment features (e.g. dove tails, mortise-and-tenon joints and even snap-fits in wood). Even adhesive bonding, using natural adhesives, existed. So, in the Second Millennium, we saw the invention of the thermal bonding of plastics (in the 1960s and 1970s), because we invented plastics in that same millennium (in the 1940s and 1950s). Also, we made remarkable advances in fusion welding with the discovery of oxygen (by LeChatelier, 1895) to allow oxy-fuel torches to be developed, and with the ability to produce and control electricity in the form of resistance (Joule, 1856), arcs (in 1881), plasmas (in 1909) and beams of electrons (in the late 1950s) or photons (as lasers, in 1960) as the basis for more intense energy sources for welding. (In fact, our ancient ancestors knew how to focus light with pieces of glass to use the concentrated energy of the sun to all sorts of ends, including joining!)

Understand, it's not that we stood still for a millennium. Undeniably, we made lots of progress. But, nearly all of it - if not all of it - was evolutionary. Lots and lots of refinements, and some spin-offs. Higher energy capacity and intensity (or density) electrical energy for welding; a host of synthetic polymer adhesives for bonding almost anything; analogs of wooden snap-fits in plastic and (more recently) metal; miniaturization of hook-and-loop fasteners found in plant burrs in plastics as Velcro™ or Dual-Locks™. All clever. All useful. But nothing revolutionary!

I'm not suggesting that evolution is bad. After all, it's natural. And, progress can be made. But, it's slow and it's predictable and it can be stiffling. Let me remind you that major advances come about from revolutions - in technology, just as in society. Let me suggest - or let me hope - that the next, Third Millennium will be one of revolutions. Revolutions in medicine to eradicate the ravages of disease and aging. Revolutions in social structures; to eradicate war and poverty. Revolutions in communication and transportation; to make the world truly one community. Revolutions in energy generation and transformation; to fuel the world while freeing it from pollution. Last, but not least, revolutions in materials to enable all the other aforementioned revolutions - and more! And, enabling new materials to achieve new levels of performance, new joining processes. Perhaps, revolutionary joining technologies. What ones? If I knew, I'd either win a Nobel Prize for the idea, or win at the race track because of the crystal ball I'd have to have. But, I don't have a crystal ball; just dreams.

We need to enter the Third Millennium ready to create revolutions in materials and in joining technologies. Recombinant DNA. Gene splicing. Genetic engineering. Optical computing. Molecular computing. Biocomputing. Energy from fusion of the inexhaustible supply of hydrogen and deuterium from the seas. Travel by hypersonic aircraft or by high speed levitated trains. Travel to the planets - nay, to the stars. Perhaps even travel in time. Who knows? Let's just dream - and prepare for the revolution; not to be left behind.

This special issue looks at joining technology; reflecting on how far we have come, and suggesting how far we have to go and how we might be starting to go there.

Reference

Messler, R.W. Jr (1996), "The challenges for joining to keep pace with advancing materials and designs", Materials & Design, Vol. 16 No. 5, October, pp. 261-9.