3D Printing Technology: Manufacturing technologies present new opportunities for R&D prototypes and high-end manufacturing facilities

R&D Magazine
April 26, 2012


Flight Testing 3D Printing

For years, aerospace engineers have been inspired by the natural world, and many have built and flown biologically inspired vehicles. Engineers at Lockheed Martin Advanced Technology Laboratories (ATL), Cherry Hill, N.J., are designing, flying, and 3D printing Samarai, a family of unmanned aerial vehicles (UAVs) that mimic the shape of winged maple seeds—samaras—that float to the ground each spring. The vehicles are structurally simple, and inherently stable in flight.

Shahrukh Tarapore, senior research scientist at Lockheed Martin Advanced Technology Laboratories, examines the 3D-printed Samarai as he pulls it from the Stratasys Dimension 3D printer. Image: Lockheed Martin Advanced Technology Laboratories

Since 2009, Lockheed Martin ATL engineers have been producing and flying Samarai using traditional materials and manual manufacturing. However, the team is now investigating 3D printing to produce the vehicles.

The research project has two goals. The team will explore whether or not 3D printing can drastically reduce the time and costs required to design and manufacture the small UAV. Also, the team plans to develop a tool that takes specific mission objectives—such as flight duration—as input and automatically produce a customized vehicle design that meets these objectives. This research could go far beyond the Samarai platform, as the technology could be extended to support other complex systems.

3D printing also helps gain insight into how the Samarai wing design affects flight characteristics. Single wing, or monowing, flight is not well understood, and the rapid manufacturing of different designs through 3D printing, combined with testing the different variants and measuring resulting performance, enables rapid exploration of the flight design space.  To read more click here...

New Life for 3D Printing

The additive manufacturing industry is populated by a broad family of technologies and some high-end systems can achieve impressive results with metals and polymers. Developments in ceramics may soon make a big impact. The low end of the market has recently been shaken up by the entry of some very low-cost systems that are causing a lot of excitement in the hobbyist market. 

The first 3D-printed full jaw replacement was made in laser-sintered titanium by the Belgian company LayerWise. Image: LayerWise

Metal parts made by laser sintering of powders top the list in performance. A wide range of stainless and tool steels, titanium and nickel alloys, and cobalt-chrome, as well as copper, aluminum, and precious metals can all be formed in machines built by companies such as EOS (Munich), Concept Laser (Lichtenfels, Germany), Renishaw Inc. (Wotton-under-Edge, U.K.), and Phenix Systems (Riom, France). Metal parts are fully dense, with a uniform microstructure due to the localized melting of a static powder bed. Titanium parts meet American Society for Testing and Materials (ASTM) standards for wrought titanium and exceed the strength and toughness of cast materials.

Laser cladding systems, such as those built by Optomec (Albuquerque, N.M.) and POM Group Inc. (Auburn Hills, Mich.), operate by jetting metal powders through a nozzle directed at a focused laser spot. These systems are able to build up parts from different metals in different locations, and are also able to effect repairs on damaged parts.

Medical implants are a very lively market for additive manufacturing metal parts. Recently, a complete lower jaw was fabricated in titanium by the Belgian company LayerWise on an EOS machine, and subsequently coated with a bioceramic by plasma spraying. Smaller custom-fit cranial implants, as well as dental implants and copings, are becoming more and more common.

More than 30 different systems make plastic parts of some type. Unlike laser-sintered metals, polymeric parts generally don't meet the same standards as conventionally processed materials. This shortcoming has relegated most processes to design prototyping and display models.

The additive manufacturing industry was founded in the mid-1980s by 3D Systems, Rock Hill, S.C., with a technology called stereolithography, which is still one of the most widely used and profitable methods. It is moderately fast, accurate, and very reliable. It is also laser-based, but rather than directing the laser onto a bed of powder, the laser is focused on the surface of a bath of photopolymer that is selectively cured in layers. The resulting parts—mostly epoxies and acrylics—are transparent and relatively tough. Stereolithography parts are useful for displaying the internal components of assemblies.  To read more click here...

Source: R&D Magazine