SLM- New technology to construct Aircraft engine components

The most recent growth in technology had grown to a greater extend that aircraft components with a complex shape can have a quick manufacture with selective laser melting in a cost effective way. This is one of the latest discoveries known by the name FANTASIA project carried out by the researchers at the Fraunhofer Institute for Laser Technology ILT and is sponsored by the European Union. The introductory presentation of this new technology was being done on 5 to 7 May 2010 at International Laser Technology Congress AKL’10 in the German City of Aachen. The invention came like a gift for the Fraunhofer ILT, from the member researchers on the occasion of its 25^th anniversary.

Unlike in the case of engines of other vehicles both in land as well as water, the engineers who are engaged in the design and development of aircraft engines will have to face major challenges in each and every assignment they are into. The components of an aircraft engine must be very light in weight and should perform under extreme temperature as well as pressure conditions.  Sometimes they need to withstand temperatures such as 2000°C and also should perform a very fast rotation in each second such as 1000 times per second. These extreme conditions restrict the researchers to take enough freedom while they are in the process of design and development of aircraft engine components.

The new invention made by the researchers at the German based Fraunhofer Institute for Laser Technology ILT is on the basis of the method selective laser melting (SLM). This method keeps in line of the chassis of the aircraft engine components on a powder-based material platform that is constructed on a layer by layer structure. The technology used in this selective laser melting (SLM) is very similar to the technology we use in a computer printer. In it, the computer brings forth a design of the data for the planned part, and then metal powder is applied in those planned areas of the substrate. After applying the metal powder it is made to melt by using a high-power laser beam to constitute a permanent bond with the completed object components of the engine. This technology is proved to be grandeur as the quality of the aircrafts components manufactured with this method is greater than those made with conventional methods.

Apart from building new aircraft components, it also can be used to repair the damaged engine components .The newly invented technology can be utilized not only to construct a new set of components for an aircraft engine, but, it also can be employed to repair the damaged parts of the old aircraft engines. This three dimensional computer printing technology in aircraft engine manufacturing process is more easy when compare it to the conventional processes such as milling or casting. “This also permits the kinds of geometries and designs we once could only dream of.” commented Dr. Konrad Wissenbach of ILT. His words give a fairer picture of the potential of this latest technology. The time required to manufacture the engine components with this along with other laser technologies saved almost 40% lesser than the conventional methods. This will also bring through 50% material costs as well as 40% repair costs when compare it with the traditional ways of producing the aircraft engine components. 

Even though SLM seems to have a superior approach, it does not suit with all the materials of turbine construction. It gives a top performance with Inconel 718, a nickel-based super alloy, as well as titanium alloys. The researchers hope to make it compactable with other fissure-prone materials. They expect to find methods to reseal the cracks in the engine during use by using melting or molding. To make it done these researchers are making several experiments by using different parameters. They try it with varying laser output power, beam geometry and the structure strategy. The product quality is expected to be improved by the effects brought out through the preheating of construction-platform. Along with the product quality, the productivity of the method also needs to be taken care of so that larger components can be manufactured faster than they are now. The comment of Mr. Wissenbach shows the expectation of the team of researchers. He said, “This is an area where we can combine a larger beam diameter for large surfaces with a smaller diameter for the contours,” “By doing this, we want to increase our speeds by a factor of ten.”