January_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 1 8 1 2 PROCESS TECHNOLOGY NEUTRONS GONE WELD Researchers from the Technical University of Denmark and Colorado School of Mines, Golden, are turning to neutron analysis to validate a high-pow- er laser welding technique for use on supersized monopiles—enormous steel cylinders that support offshore struc- tures such as wind turbines and oil rigs. Using the Neutron Residual Stress Map- ping Facility at the DOE’s Oak Ridge National Laboratory, the team is com- paring the residual stresses produced by traditional submerged arc welding to those pro- duced by the newer hybrid laser-arc welding process. They are also examining the relationship between residual stress and differ- ent thicknesses of steel plates, analyzing samples that are 10, 20, 40, and 60mmthick. Neutronmap- ping is the only imaging technique that can pene- trate the steel to reveal changes in residual stress on the atom- ic scale. Submerged arc welding uses elec- tric arcs and a granular flux, in which the molten seam is submerged. While the technique produces fewer impuri- ties, sparks, and toxic fumes than sim- ilar methods, it requires material to be removed and filler material to be add- ed, a costly process that introduces considerable residual stresses, which thereby increase corrosion rates. Hy- brid laser-arc welding, on the other hand, uses a more focused heat source that mitigates residual stress and corro- sion. The team’s findings could lead to more efficient and afford- able production methods, as well as stronger, longer lasting welds. ornl.gov. SPOTLIGHT ON MULTI-MATERIAL PRINTING Scientists at the Uni- versity of Nottingham, UK, developed a new printing method that combines 2D printed electronics with 3D additive manufacturing to produce a fully functional electronic circuit in a single process. The breakthrough tech- nique uses compact, low cost, LED- based UV light to quickly solidify both the circuit’s electrically conductive me- tallic inks and its insulating polymer- ic inks instead of relying on separate methods for each ink. Silver nanopar- ticles in the conductive inks efficient- ly absorb UV light and convert the en- ergy to heat, which evaporates the ink’s solvents and fuses the nanoparticles— without damaging adjacent polymer ink. The conductive ink is solidified in less than a minute per layer, a process that previously required heat sources like ovens or hot plates and took con- siderably longer. The new approach will enable fabrication of fully customized electronic components, such as 3D an- tennae and sensors. “You don’t have to select standard values for capacitors when you design a circuit,” explains Chris Tuck, professor of materials engi- neering. “You just set the value and the printer will produce the component for you.” www.nottingham.ac.uk . Schematic diagram shows how UV irradiation heats and solidifies conductive and dielectric inks to form the letter N with silver tracks that connect a green LED to a power source. Courtesy of University of Nottingham. Submerged arc welding features a significantly wide groove with high inherent residual stresses. Courtesy of DTU/Daniel Sommerlund Pedersen. Chassix Inc., Southfield, Mich., signed a definitive agreement to acquire the lightweight aluminum, low-pressure automotive casting business of Benteler Automotive Farsund AS, Norway. The division, which boasts a highly automated foundry, designs and produces lightweight aluminum structural castings, including safety critical components such as sub frames, swing arms, steering knuckles, and rear hubs for the luxury auto- motive industry. chassix.com . BRIEFS TimkenSteel, Canton, Ohio, is processing orders at its new ad- vanced quench-and-temper facili- ty. The addition of the $40 million facility, located at the company’s Gambrinus Steel Plant, increases its quench-and-temper capacity by 50,000 tons, or 45%, bringing the total annual thermal treat- ment capacity to 500,000 process tons. timkensteel.com .