July_August_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 U L Y / A U G U S T 2 0 1 9 6 8 3D PRINTSHOP HOW TO MAKE PORES DISAPPEAR Researchers at Lawrence Liver- more National Laboratory (LLNL) and scientists at the SLAC National Accel- erator Laboratory combined the use of x-ray imaging and simulations to miti- gate defects in metal 3D-printed parts. Their strategy negates the formation of pores, thus preventing the initiation of cracking under stress. The process in- volves reducing the power of the laser as it slows down to make its turn along the serpentine path it takes to scan and build a metal layer. By varying the laser power throughout the build, the team found they could keep the laser’s de- pression depth shallow and constant. They discovered that during the printing process, as the laser melts the metal powder and makes the turn, the laser’s power density intensifies, penetrating deep under the surface. This forms a “keyhole depression” and leaves tiny bubbles of gas trailing be- hind it in the solidifying metal. These bubbles then cause pores to develop under the surface of the printed object. The mitigation technique the team developed is part of a suite of tools tied to the lab’s intelligent feed-forward strategy, which relies on simulations and model validation prior to printing. Researchers say the strategy could be deployed on virtually any commercial machine by constructing power maps with 3D slicer software that converts the parameters defined by a CAD file into machine instructions. Because laser powder bed fusion is the pre- ferred method of metal 3D printing for many larger automotive and aerospace companies, the team anticipates the mitigation strategy will be adopted for use by industry. llnl.gov. post-processing machines, wet-booths, and multiple furnaces. The new facility is capable of producing tens of thou- sands of parts representing in excess of $100 million of additive manufacturing revenue annually. The expansion is an- ticipated to bring more than 130 new jobs to the area. sintavia.com. LARGE-SCALE PARTNERSHIP The advancement of large-scale robotic additive manufacturing tech- nology just got a boost via the contin- ued collaboration between Oak Ridge National Laboratory (ORNL) and Lin- coln Electric. From left, TomMatthews of Lincoln Elec- tric and Thomas Zacharia, ORNL director, signed their additive manufacturing agreement during the DOE’s Advanced Manufacturing InnovationXLab Summit. Ribbon cutting ceremony at Sintavia’s grand opening on May 9. HOLLYWOOD WELCOMES NEW AM FACILITY In May, Sintavia LLC opened a new 55,000-sq-ft advanced manufacturing facility in Hollywood, Fla. A Tier One metal additive manufacturer for the aerospace and defense industry, Sin- tavia plans to use the new plant as its headquarters. The grand opening was attended by over 150 customers and in- dustry partners. Sintavia’s new facility houses over $25 million of advanced manufacturing equipment including metal printers, X-ray imaging along with the laser powder bed fusion process allows researchers to negate pore formation in 3D-printedmetal parts. Their new agreement, signed during the DOE’s Advanced Manufac- turing InnovationXLab Summit, builds on ORNL and Lincoln Electric’s previ- ous developments by extending addi- tive technology to new materials, us- ing data analytics, and enabling rapid manufacture of metal components in excess of 100 pounds per hour. The goal is to focus on increasing throughput while lowering costs and improving the quality of large-scale additively man- ufactured metal structures essential for industrial applications. ornl.gov, lincolnelectric.com.