Speaker: Thomas Ales
Title: “Large-Scale 3D Orientation Microscopy Using Photon Based Method”
Abstract: Previous research has demonstrated that grain orientation and texture play a significant role in influencing the properties of a build. The length-scale of the texture that is seen in large-scale additively manufactured builds is correspondingly large, often reaching centimeters in length before repeating. Consequently, it would be troublesome to characterize using conventional techniques such as EBSD. To make the group’s physics-based model more accurate and complete, a source of large-scale texture data was required to properly incorporate the effects of the build itself on the final performance predictions. Spatially Resolved Acoustic Spectroscopy (SRAS) can give orientation data for cubic structures and hexagonal structures for large areas that would be impossible to study using EBSD.
We have been developing a new variant of SRAS, SRAS-3D (and establishing only the second location in the world capable of conducting basic SRAS measurements). Our objective is to collect volumetric data and use that to better inform our property-based models based on the textures observed and use the collected representations as starting points for mesoscale mechanical modeling compared to presently generating synthetic, or mimic structures in DREAM.3D or equivalent software. There are extensions into impacting modeling in conventional NDE methodologies.
This seminar will first focus on what happens when you must build a new tool that you require to even enable the research you would like to do. This talk will assess, honestly and openly, critical transition points, such as the many dead-ends, departed electronics and analyses that drove several major revisions either due to spiraling complexity or insufficient performance once realized. It will also go over some of the out-of-band engineering skills that were required create the system of systems that is the serial acoustic microscope. These skills have ranged from the development of custom mechatronics, electronics and optical systems, to writing software to plan scans, post-process and fuse the data into a workable representation of ‘ground-truth’ data.
The second half will present the first volumetric dataset of a Titanium Beta-21S sample captured through the serial acoustic microscope, which consists of the built SRAS microscope and a Robo-Met.3D with widened working cell.
Bio: Thomas Ales is a research scientist at Iowa State University. He received his master’s degree in Materials Science and Engineering from Iowa State in 2018 on the topic of developing an integrated modeling approach to predict properties and performance in electron beam additively manufactured Ti-6Al-4V. His research culminated in a co-authored patent with Drs. Collins & Thuo on the control of interstitial species during additive manufacturing, as well as catalyzed the significant efforts to develop a new type of laser-based acoustic microscope. Prior to Iowa State, he worked at Titanium Engineers and AlTiSSTechnologies in Sugar Land, Texas as a project engineer, contributing to the design and proof testing of high-pressure, high-temperature, sour-service autoclaves in addition to overseeing the manufacture of precision metering windows for use in the Oil & Gas industry. He brings a practical view of engineering to the research that he conducts.
Seminar Host: Pete Collins
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