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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 1 3 PROCESS TECHNOLOGY LASER WELDING RESEARCH PROGRESS Computer modelers are beginning to use data on the most fundamen- tal aspects of laser welding to improve simulations of these welding processes, a necessary step to prepare the work for industry. Scientists at the Nation- al Institute of Standards and Technolo- gy (NIST), Gaithersburg, Md., have been collecting this comprehensive data for the past three years. Essential to many industrial pro- cesses, achieving more efficiency in welding is a huge advantage in produc- tion. Laser welding is not only more ac- curate, but also faster and more ener- gy-efficient than conventional welding. A better understanding of the process could make it easier for industries to consider investing in laser welding in- frastructure, say researchers. Comput- er models can help manufacturers save time and better understand which com- bination of laser settings will produce the best weld for their appli- cation. To make the models, though, researchers need data from past experiments, which is currently spread across hun- dreds of studies representing decades of work from numer- ous laboratories. As such, the NIST team is attempting to build a much firmer foundation for a mod- el. The scientists are measur- ing everything that a simulator would need—the amount of power that is hitting the met- al, the amount of energy the metal is absorbing, and the amount of material that is evaporating from the metal as it is heated—all in real time. To sense these minuscule signals, researchers are adapting a technique called laser-induced fluorescence (LIF) spectroscopy. The method involves hit- ting the plume with a second laser that targets just one kind of element at a time. So far, the team has demonstrat- ed that LIF can sense trace elements in the weld plume with 40,000 times more sensitivity than traditional methods. Another important aspect of the work is that researchers are conducting all of their experiments with a type of stain- less steel that is a NIST standard refer- encematerial (SRM). Using the stainless steel SRM ensures that experiments conducted anywhere in the world can have access to metal samples with an identical composition, so that everyone is effectively contributing to one big project. nist.gov. MUSSELS INSPIRE UNDERWATER ADHESIVES Scientists from Washington Uni- versity, St. Louis, are replicating the glue-like protein of mussels to improve it for everyday use. The strong, micro- bially produced underwater adhesive could have many applications—it could even help to fix the very boats now plagued by the mollusks. While most synthetic glues do not work on wet surfaces, mussel foot proteins (Mfp) function in such conditions, even un- derwater. This property makes Mfp suit- able for many applications, from under- water repair to biomedical glues. The power of synthetic biology is that researchers can fine-tune the prop- erty of protein materials by manipulat- ing their genetic codes. When the re- searchers made the Mfp protein chain longer, its underwater adhesion was stronger than that with natural chain length. This biosynthetic approach could allow the team to explore many unknown mechanisms that control un- derwater adhesion, parameter by pa- rameter. wustl.edu. Inside NIST’s laser welding booth, a high-power laser melts a piece of metal. Courtesy of Paul Williams/NIST. BRIEF Emerson, St. Louis, will invest $49 million to build a new global headquarters in Brookfield, Conn., for its Branson assembly technologies product line. The new facility will include state-of-the-art laboratories, offices, manufacturing space, and a customer experience center. Branson products are used for plastic joining, ultrasonic metal joining, and precision processing. emerson.com . The adhesive protein of mussels are the model for a new, synthetic adhesive that also works under water. Courtesy of Zhang lab.