Direct Metal Laser Sintering (DMLS), known also as laser sintering, selective laser sintering or selective laser melting is an additive manufacturing process, already adopted by industries such as aerospace, automotive or defense for the production of high-quality components with specific mechanical characteristics. This is a process of powder bed fusion where thermal energy is applied on selective regions of a powder bed to melt the metal powder. The different steps can be described as follow:
- CAD Modeling
A CAD Model carries the most accurate information about the desired components and sends it to the 3D printer. The process begins with slicing of the 3D CAD file into many cross-sections. This can be done using existing design softwares (Solidworks, Rhino, ProE, SolidEdge, etc.) and combining a slicer program typically proprietary to the printer being used.
- Powder melting
A laser selectively melts or sinters the used material, mainly high-quality metal powders such as the superalloy Inconel 718 to build the first layer of the 3D component.
- Layer Building
After that the recoater applies a new layer of powder on the build platform, which is then again selectively melted by the laser to create the next cross-section of the component. The cycle is repeated layer by layer, sometimes adding material layers that are measured in nanometers of thickness.
- Finishing operations
After all layers have been sintered together to create the entire part, some additional finishing operations as shot-peening, heat treatment or electrical discharge machining can be performed.
Selective laser sintering offers good metallurgy which results in improved mechanical properties. Complex shapes and geometry that canít be done with subtractive manufacturing can be easily created when applying laser sintering. Another important advantage is less material consumption and little to no manufacturing waste, which results in energy efficiency and cost reduction. And last but not least, selective laser melting links directly the engineering process to the manufacturing process, and then reduces lead-time and entirely changes the time to market goals of the product development process.
Since direct metal laser sintering employs big state-of-the-art industrial printers, it is mainly adopted by leading industrial sectors as automotive, aerospace and defense with high demand for complex, robust and very strong components. Some of the key-players in the manufacturing of high-quality industrial 3d printers capable of metals are EOS, Stratasys, and ExOne. The consumer sector, which requires smaller, lower cost machines include 3d systems, and Makerbot.
The automotive industry has always been a critical component of economic growth, national and regional employment of every industrialized country. Today this market faces the challenges of the 21st century as emerging markets, financial pressure from higher raw material prices and the never ending environmental problem. The need to grow and change smartly through technological advancement and highly innovative solutions is more than obvious. Newer designs, shorter lead times and lower cost are only some of the advantages of direct metal laser sintering.
In todayís global world, connecting people and shipping freight through fast and cost-effective transportation has become essential for international trade and tourism. But besides endless opportunities, globalization also brings unprecedented challenges. Environmental performance commitments, increasingly complex and demanding government requirements and competitive market conditions are just some of them. Additive Manufacturing might not be able to solve global pressure in short-term, but will definitely contribute to the technical improvement of the aerospace industry in most quality and cost-effective manner, meeting industryís stringiest requirements.
Defense and national security sectors are involved in research, development, production, and service of military material, equipment and facilities. On the one side this is a huge export market, which should deliver support, training and regular upgrades in a long-term relationship. But also, this is the most important investment for a country and therefore governments seek for high-reliable partners. The sector faces constantly the need for innovations and cost reduction. This is where direct metal laser sintering contributes to the improvement of the production development process. Laser-sintered small quantities of lightweight components eliminate tooling investment and bring considerable cost benefits.
The tooling industry is fundamental to high-quality manufacturing. Actually all the industrial sectors would not be as productive as they are without the support of the tooling industry. Dies, molds, machine tools, cutting tools, wear parts, tongs, pliers and many others are used in stamping and forging operations or to shape ceramics and composite materials. Despite the recent progress, the tooling industry is still plagued by insufficient manufacturing speed, accuracy and efficiency. Selective laser sintering can optimize the manufacturing process of industrial tooling in a cost efficient way. Additive manufacturing can deliver complex lighter shapes with added functions and ergonomic design.
Comprising watches, jewellery, accessories, packaging and many more, luxury is the ultimate emerging market for 3d printing. Besides the development and industrialization process, there are not so many applications of additive manufacturing in the luxury sector so far. But due to time to market and customization advantages, additive manufacturing for luxury items unveils huge potential. Even though designers prefer the use of smaller printers; many applications require quantities for which a larger printer will be a better choice.