January_2021_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 2 1 1 1 loss fine structure spectra pixel by pixel, the abundance of various aluminum structures was determined with nano- meter precision. The data was then interpreted with computer simulations. “Aluminosilicate glasses can be manufactured to resist high tempera- tures and compressive stresses. This makes them useful for a wide range of industrial and consumer applications, such as touch displays, safety glass, and photovoltaics,” says Teruyasu Mizo- guchi. www.iis.u-tokyo.ac.jp/en. IDENTIFYING STRESS IN 3D PRINTING As part of an international collab- oration led by Linköping University, Sweden, along with ANTSO, Australia, researchers have discovered the origins of key adverse stress formation in the additive manufacturing (AM) process. They found that a careful selection of the printing orientation is important and has a significant impact on the magnitude of residual stresses and, therefore, the potential distortion of the AM part. Researchers chose to focus on an L-shape to study the effects of a built-up orientation. Three experimental ap- proaches were used to characterize the residual stresses in L-shaped parts. X-ray diffraction measurements were used to characterize surface stresses and laser scanning techniques mea- sured overall distortions associated with separating the samples from the base plate. Neutron diffraction was nec- essary tomeasure residual stress in the interior of the samples due to the high penetration of neutrons. The part printed in a horizontal orientation showed the least amounts of stress in all three direc- tions, showing the way for the optimization of the build-up of generic L-shapes. However, in all orientations, there was a general tendency for compressive stress at the center of the part. Tensile residual stress was observed near the surface in all samples, which appears to be potentially problematic. The research included the development of a simplified simulation technique using finite element analysis for predicting residual stresses based on part geom- etry, which, when verified with neutron experimental results, was in a good practical agreement. www.ansto.gov . au, www.strategiska.se/en. L-shaped samples before and after 3D printing.

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