Special coatings protect components against corrosion and wear. However, standard processes such as hard chrome plating, thermal spraying, laser material deposition or other deposition welding techniques have drawbacks. For example, as of September 2017, chromium(VI) coatings will require authorization. Researchers from the Fraunhofer Institute for Laser Technology ILT in Aachen as well as the RWTH Aachen University have now developed an extreme high-speed laser material deposition process, known by its German acronym EHLA, to eliminate these drawbacks in an economical way.
Additive manufacturing (AM) methods of 3D printing are increasingly opening up new paths in medical technology. Alex Berry, founder of Sutrue (cf. Interview, p. 20), and Richard Trimlett, consultant at the Royal Brompton Hospital, are focusing strategically on AM for applications in cardiology. Is it possible to improve the “golden hands” of an experienced heart surgeon? Yes, it is. Using the example of a machine for performing sutures during operations and a cardiac stabilizer for endoscopic heart operations, Sutrue shows how operations on the heart can be performed more safely. Heart operations are soon to become faster and safer. And there is even more good news: patients are recovering faster.
The consumer electronics and automotive industry are the driving forces for an increased use of copper in industrial processes and products. With the development of new battery technologies and higher battery capacities, the demands to the joining technologies are increasing. While soldering is still the state of the art for low power applications in consumer electronics, it is necessary to apply welding technology whenever high currents have to be transmitted, or high and dynamic loads stress the joints. The e-mobility sector is especially driving this trend and the automotive industry and its suppliers are looking for robust and efficient processes for high volume production in electrical power storage and transmission line applications.
The master oscillator power amplifier (MOPA) fiber laser has been around for several years but the bulk of applications use Q-switched fiber lasers. Now, with the processing capabilities of the Q-switched fiber laser fully explored, the MOPA fiber laser is getting revived attention. Laser-diode seeded MOPAs hold promise of arbitrarily modulated high-power laser output. Pulse-pumping the amplifiers to handle ON/OFF gating and low repetition rate pulse trains without overshoot or undershoot is of special interest.
Laser ablation is gaining popularity for medical device applications that require stripping of coatings on cylindrical components like hypotubes and guide wires. It is also being widely used for advanced surface treatments, including discoloration or foaming of plastics and darkening or annealing of metal parts. Offering a repeatable non-contact process, laser ablation is a clean, low dust (or no-dust) way to selectively remove wire layers or areas. It is also a fully automated process, with a very high yield compared to other methods.
Industrial use of nanosecond lasers for applications such as marking, engraving, cutting, and even micromachining is well known – however, the use of these sources for welding and joining is relatively new. Most applications of high-peak-power, short-pulsed lasers tend to be related to material removal, so their use for joining is perhaps counterintuitive. However, the versatility afforded by master oscillator power amplifier (MOPA)-based nanosecond fiber sources give unparalleled flexibility in terms of control of the output characteristics. These lasers can be used, for example, with high-peak-power nanosecond pulsed output with tunable pulse duration and high frequency-modulated quasi-continuous-wave (QCW) modes, as well as operated as a more conventional continuous-wave (CW) laser.
A new generation of ultrafast lasers with high average powers and high repetition rates is coming to the market. Those systems in principle bring together high precision processing and high throughput. But with high average power thermal effects show up the demand for a careful process planning. A new simulation tool from Fraunhofer ILT incorporates such effects and allows for precise process optimization even at high average laser power.
What do have shoes, brake callipers, Coke and cow earmarks in common? The permanent laser marking. Whether batch or charge number, best bevor date, official registration or further data – the production of consumer or industry products cannot be imagined without laser marking. With its unique performance laser marking guarantees extremely reliable, very flexible and automated markings for “eternity”. Numerous industries, as for example automotive, fashion and food industry as well as medical engineering perch on laser marking for identification, labeling, branding, product security and backtracking purposes.
Lasers have been employed in a variety of welding applications for many years. And, as laser technology further develops and diversifies, its uses in welding continue to expand. This article provides an overview of high power lasers in keyhole welding. It then examines the characteristics and advantages of fiber laser sources for welding from Coherent-Rofin, in particular, and reviews a specific application that has benefitted from these lasers.
Boiler tubes in biomass and incineration plants are exposed to extreme operating conditions. To create vapor pressure within the pipes that makes an effective drive of the power-plant turbines possible, flue gas temperatures of up to 1000 °C must be realized within the combustion chamber of the boiler. No pipe-material will sustain the chemical processes induced in this way for very long. Already at temperatures of 350 °C, the chlorine in the flue gas increasingly reacts with the iron of the ferritic pipe materials. A rapid and progressive oxidation process begins and reduces the wall thickness of the pipes, which can lead – using unprotected pipes – to tube leakage in some cases within less than one year (Fig. 1). In order to improve the lifetime of pipes, many power plant operators count on metallic or ceramic corrosion-protection coatings. With their help, the material decomposition process can be delayed and the lifetime of the pipes can be tripled or even quadrupled. However, the investment in a coating in most cases is profitable already if lifetime of pipes is doubled because the exchange of corroded pipes requires new tubes plus a temporary shutdown of the whole boiler system.
Tucked away behind the glass facade of Trumpf headquarters is a brain-storming room used by an additive manufacturing team. This is where they craft strategies and opportunities to make this promising technology more productive and to extend its appeal to a broader user base. Although additive manufacturing is a hot topic and a popular choice for small-batch production and prototyping, a lot must happen before additive manufacturing can compete with more established metal-processing technologies in small and medium-sized enterprises. The process must become more robust, reproducible and economical.