LMD grows stronger in additive manufacturing for industrial applications

By Niraj M Wanikar, Chief Editor, CNCTimes.com, 2016-11-17 12:15:00

Repairing, coating, refining, joining, or creating from scratch - as a versatile manufacturing technology, laser metal deposition (LMD) has matured into a strong additive technique for industrial applications. At the formnext trade exhibition in Frankfurt, Germany, the laser system manufacturer TRUMPF is showcasing new solutions and applications for LMD technology.

With its laser metal deposition portfolio, TRUMPF is targeting a wide variety of sectors and applications. As well as additive manufacturing, this also includes joining technology and the manufacture of coating systems. In Frankfurt, the primary focus is on repair applications in the aviation industry and the combination of various laser-based technologies in a single machine.

Huge cost savings thanks to LMD technology
In aviation, the LMD method is already a mature, established technology: it is used, for example, to repair gas turbines or compressor blades. The process is stable and reproducible, and the quality of the deposited volumes meets the high requirements of the aviation industry. In this sector, maintenance tasks and the servicing of technical systems and machinery offer high growth potential for the LMD method.

To give a concrete example: so-called blisk (blade integrated disk) technology is becoming increasingly popular in the field of engine and turbine construction. A blisk is a component that consists of a disk and several blades. The advantage of blisk technology is that it allows manufacturers not only to bring down assembly costs, but also - and more importantly - to reduce the overall weight of the turbine or engine.

However, there is also a drawback: if a blisk becomes worn or damaged, it is awkward and expensive to replace. LMD makes it possible to repair and restore blisks by mending damaged sections or cracks using laser and powder. Through this expedient alone, turbine and engine manufacturers can reduce their repair costs by up to 92 percent.

High build-up rates in every spatial direction
In addition to repairing high-value components, the refining and coating of components continues to be one of the main fields of application for LMD. This involves applying a few layers of material to the component, the goal being to improve the surface characteristics and protect the component against problems such as wear and corrosion.

Regarding the technique itself: The laser creates a weld pool on the surface of a substrate and fuses the powder, which is added coaxially at the same time, into the required shape. The deposited volume can grow in any spatial direction one likes; build-up rates can reach as much as 500 cubic centimeters per hour. When geometric complexity allows, whole components can then be generated using the LMD technology.

Taking a broader view, this could also be relevant for numerous repair applications in the future - rather than repairing components, they could be completely remade from scratch. In certain cases, LMD can even provide an alternative to conventional joining technologies; the bridging of gaps is a good example of such an application. Because the powder is very fine-grained, it produces homogeneous welds with outstanding surface quality - and without the need for mechanical post-processing.

Mature all-purpose LMD package by TRUMPF
TRUMPF has long had the manufacturing equipment required for the LMD method in place: depending on the particular application, the company can equip five- or three-axis machines - or even robot-based machine concepts - with LMD technology. At formnext in Frankfurt, TRUMPF will also be showing how to combine LMD with various other manufacturing techniques in a single machine.

At the trade exhibition, for example, the compact TruLaser Cell 3000 is fitted with a laser head that combines additive manufacturing and cutting technologies working in harmony. In automated manufacturing, these kinds of combined techniques are a decisive factor as regards productivity.
Digital photographs in print-ready resolution are available to illustrate this press release. They may only be used for editorial purposes. Use is free of charge when credit is given as "Photo: TRUMPF". Graphic editing - except for dropping out the main motive - is prohibited.

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