Despite the ancient origins of welding, it was only twenty years ago that laser welding began to emerge on the scene. It was principally used for highly specialized applications which were unsuitable for other, more traditional, welding processes. Nowadays laser welding has been fully integrated into metal working and is used for the most commonplace of applications, both the commercial and the highly technical, e.g., hermetic seals, cigarette lighters, hybrid circuit packages and pacemaker components, to great success. Curiously, manufacturing engineers remain reluctant to factor laser welding into their own operations.
Inhibitors, such as the foreignness of the capabilities and operation of laser welding systems, high start-up costs, and concerns about employing lasers in a manufacturing environment, are believed to be the culprits behind this. However, there is a strong case for using laser welding in standard processes, such as submerged arc, RF induction, high-frequency resistance, resistance (spot or seam), and ultrasonic and electron-beam. These niche manufacturing processes would be extremely well served by replacing traditional welding with laser welding, which could yield improvements in the efficacy of multiple applications.
Laser welding’s versatility means that it can readily replace traditional welding processes, such as those mentioned above, efficiently and economically, and it can serve other purposes, such as cutting, drilling, sealing, scribing, and serializing. In fact, welding industry insiders say the number of laser machine tools in use could grow from the current 2,000 to almost 30,000 over the next 15 years. Let’s look at how laser welding works and the benefits that manufacturing engineers can expect to derive from its use.
To start, the ability of lasers to reach difficult spots, provide a range of energy output, and be guided by robots or computers, thus allowing for greater control of the heat in a given part, makes them highly attractive for many manufacturing operations. It is the precision control of lasers, both directionally and dimensionally, that makes them highly functional for hardening specific areas as opposed to heating an entire part.
Unique Characteristics of Laser Heat Treating
In much the same way that a piece of glass can focus and harness light and generate heat on a highly discrete spot, lasers can concentrate light on extremely small spots and produce high degrees of stable heat, making them extremely beneficial for welding compact focal points. Some of the advantages of this include:
- Minimal Heat Input – due to the high source temperatures, transference is rapid, dramatically reducing the amount of heat input required. Another benefit is decreased distortion to the applicable surface area.
- Precise Control – the concentration of light means greater precision throughout treatment and the advanced flexibility lasers supports projecting the heat treat area in small diameter bore via directing mirrors.
Non-Contact, Open Air Processing – because the energy source is light, nothing physical touches the part.
As laser tools become more familiar and awareness of the benefits they offer increases, the realm of applications for laser welding, will likewise expand, all of which translates into greater precision, efficiency, and productivity.
Mark Williams is the author of this article about laser welding. He has gathered sources from http://www.coherent.com/Applications/index.cfm?fuseaction=Forms.page&PageID=250 to write this article. Feel free to connect with him via Google+.