Discover Top Posts Tagged with #selective laser melting

After the events of last week I figured I'd paint up a beherit print I had.

It's been a while since I printed anything in steel, so I was quite surprised at the level of detail you can achieve with SLM printing.

#beherit #Selective Laser Melting

Technology for producing aluminum matrix composites from new raw materials

Materials scientists from NUST MISIS have presented a new technology for producing the aluminum matrix composites from new raw materials—promising composite powders for 3-D printing of light, durable cases for aircraft and automotive engineering. The new method increases the uniformity of properties and hardness of the obtained 3-D printed composites by 40% in comparison with analogs. The results have been published in the Journal of Alloys and Compounds.

Aluminum matrix composites are a group of advanced materials with a number of unique advantages: They are lightweight, have high strength, low thermal expansion coefficient and excellent wear resistance. These materials can be used in the automotive, aerospace and defense industries.

The material has such properties due to its chemical composition and a special method of production—3-D printing using selective laser melting (SLM) technology. As a result, the composite consists of spherical aluminum particles hardened with ceramic additives or coated with a layer of aluminum oxide.

Eliminating cracks in 3-D-printed metal components

Researchers at EPFL have developed a new laser 3-D-printing technique to manufacture metal components with unprecedented resistance to high temperature, damage and corrosion. The method has applications in fields ranging from aerospace to power-generating turbines.

3-D printing, also known as additive manufacturing, has revolutionized the way components are made, setting new standards in terms of production speed when geometric complexity is high.

Manufacturers use a technique known as selective laser melting (SLM) to 3-D-print metal components. With SLM, a powerful laser melts and fuses metallic powders together, gradually building a 3-D component layer by layer. Any remaining powder is removed at the end of the process. But some metals and alloys cannot withstand the high temperature variations that SLM involves, causing them to crack.

Researchers at EPFL's Laboratory of Thermomechanical Metallurgy (LMTM), led by Roland Logé at the School of Engineering, have developed a new method that involves applying a second laser treatment every few layers during the building phase. This dramatically reduces cracking and produces metal components with unprecedented resistance to high temperature, damage and corrosion.

Nature-inspired materials can be used in applications ranging from tunneling to space

Optimal materials for cutting tools of tunnel boring machines (TBM) were developed in the recently finished three-year long project "Innovative polycrystalline diamond (PDC) drag bit for soft ground tunnel boring machines" by TalTech materials scientists from the tribology and recycling group.

The history of tunnel boring machines can be traced back to 200 years ago when the first tunnels were built. In general, the materialsof a TBM that are in contact with abrasive particles can be divided into metals, ceramics and materials that combine them, i.e. composites. The composites usually have the highest wear resistance in aggressive environments. "We were trying to improve the wear resistance of materials of moving elements of a TBM and the composites were the right choice for further development," the head of tribology and recycling research group, senior researcher of TalTech School of Engineering, Maksim Antonov explains.

The tests done during the research period were following the main goal—to prolong the lifetime of TBM cutting tools in order to minimize the need for their replacement. The tools made of materials with higher wear resistance can be replaced less frequently.

Aluminum on the way to titanium strength

NUST MISIS scientists have proposed a technology that can double the strength of composites obtained by 3-D printing from aluminum powder, and advance the characteristics of these products to the quality of titanium alloys: titanium's strength is about six times higher than that of aluminum, but the density of titanium is 1.7 times higher.

The developed modifiers for 3-D printing can be used in products for the aerospace industry.

The developed modifying-precursors, based on nitrides and aluminum oxides and obtained through combustion, have become the basis of the new composite. The research results have been published in the highly rated scientific journal Sustainable Materials and Technologies.

Two decades ago, molding was considered the only cost-effective way to manufacture bulk products. Today, 3-D printers for metal are a worthy competitor to metallurgical methods. 3-D printers have a chance to replace traditional methods of metallurgical production in the future. Using additive technologies with 3-D printing creates a whole array of advantages, from creating more difficult forms and designs to the technology's cheaper cost and theoretical edge.

3D printed impeller allows unmanned aircraft to operate for thousands of hours

Southwest Research Institute engineers are developing a cooled, radial gas turbine for a small generator that provides thousands of hours of electricity to an unmanned aerial vehicle (UAV), a significant improvement to current UAV turbines that only operate a few hundred hours before wearing out.

Turbines are rotary mechanical devices that, when combined with a generator, produce electrical power.

"This turbine is part of a generator that's similar to what the average person might use to generate electricity in their home when the power goes out," said David Ransom of SwRI's Mechanical Engineering Division. "The version we're creating is more compact and efficient, tailored to the needs of a small, unmanned aircraft."

The problem with current small turbine models is that during the generator's combustion process, the turbine is constantly bathed in high temperature gas that ultimately damages or destroys it.

Breakthrough with 3D printed stainless steel

"Marine grade" stainless steel is valued for its performance under corrosive environments and for its high ductility -- the ability to bend without breaking under stress -- making it a preferred choice for oil pipelines, welding, kitchen utensils, chemical equipment, medical implants, engine parts and nuclear waste storage. However, conventional techniques for strengthening this class of stainless steels typically comes at the expense of ductility.

Lawrence Livermore National Lab researchers, along with collaborators at Ames National Laboratory, Georgia Tech University and Oregon State University, have achieved a breakthrough in 3D printing one of the most common forms of marine grade stainless steel -- a low-carbon type called 316L -- that promises an unparalleled combination of high-strength and high-ductility properties for the ubiquitous alloy. The research was published online in the journal Nature Materials on Oct. 30.

"In order to make all the components you're trying to print useful, you need to have this material property at least the same as those made by traditional metallurgy," said LLNL materials scientist and lead author Morris Wang. "We were able to 3D print real components in the lab with 316L stainless steel, and the material's performance was actually better than those made with the traditional approach. That's really a big jump. It makes additive manufacturing very attractive, and fills a major gap."

Alloys from the laser printer

In the future, new designer alloys for aerospace applications can be manufactured using the 3-D laser melting process (Additive Manufacturing). Pioneering work in this field was provided by Empa researcher Christoph Kenel, who works today at Northwestern University (Chicago). Empa grants him the Research Award 2017.

Titan-Aluminum alloys are combining low density, high strength and oxidation resistance at elevated temperatures and are therefore of high technical relevance e.g. in aerospace engineering. The aim of the awarded PhD thesis of Christoph Kenel was to develop a novel titanium aluminide (TiAl) alloy, particularly for use in beam-based additive manufacturing technologies, and to include nano-sized oxide dispersoids to improve their high temperature mechanical properties. Christoph Kenels research was supervised by Christian Leinenbach at Empa's Advanced Materials Processing laboratory.

The topic is very challenging, since TiAl alloys are inherently brittle at room temperature, and the rapid solidification conditions during AM can lead to complex phase transformation sequences, pronounced element segregation and cracking. Oxide dispersion strengthened (ODS) alloys are a class of materials that offer an unmatched combination of deformation-, creep-, coarsening- oxidation- and corrosion resistance at temperatures up to 1,000 °C.

#selective laser melting

Trending Tags

Recently Viewed Tags

#selective laser melting