Characterization of Minerals, Metals and Materials 2021: Advanced Characterization Methods II
Sponsored by: TMS Extraction and Processing Division, TMS: Materials Characterization Committee
Program Organizers: Jian Li, CanmetMATERIALS; Mingming Zhang, Baowu Ouyeel Co. Ltd; Bowen Li, Michigan Technological University; Sergio Monteiro, Instituto Militar de Engenharia; Shadia Ikhmayies, The University of Jordan; Yunus Kalay, Middle East Technical University; Jiann-Yang Hwang, Michigan Technological University; Juan Escobedo-Diaz, University of New South Wales; John Carpenter, Los Alamos National Laboratory; Andrew Brown, Devcom Arl Army Research Office; Rajiv Soman, Eurofins EAG Materials Science LLC; Alex Moser, Naval Research Laboratory
Tuesday 8:30 AM
March 16, 2021
Room: RM 15
Location: TMS2021 Virtual
Session Chair: Andrew Brown, Army Research Laboratory; Yunus Kalay, Middle East Technical University
8:30 AM
On the Origins of the Discrepancies between Optical, SEM, and EBSD-based Grain Size Measurements: Eric Payton1; Kayla Evans1; 1Air Force Research Laboratory
Accurate characterization of grain size is notably important for the development of structure-property relationships, as grain size affects nearly all engineering properties of structural alloys, from strength and fatigue life to corrosion resistance and thermal conductivity. However, a persistent discrepancy is often observed between electron backscatter diffraction (EBSD) based grain size measurements and those made using optical or electron microscopy. We investigate the origins of this discrepancy through simulating ASTM E112 and E2627 grain size measurements on synthetic microstructures. The relative magnitudes of the effects of resolution, measurement technique, and artifacts (such as image drift and low magnification distortions) will be discussed. Finally, recommendations for best practices for minimizing and reconciling differences between measurements made by the different techniques will be presented.
8:50 AM
A Correlative Approach for Distinguishing Multiple BCC Phases in Thick-Section High Strength Steels: Virginia Bertolo1; Quanxin Jiang1; Carey Walters2; Jilt Sietsma1; Vera Popovich1; 1Delft University of Technology; 2TNO
An in-depth microstructural characterisation is usually required to establish the process-microstructure-properties relationship and optimize the material. However, it remains a challenge to differentiate and accurately quantify bcc phases characteristic of high strength steels (HSS): ferrite, bainite, martensite. To address this problem, we propose a correlative approach by using a combination of dilatometry, CCT diagrams, SEM, EBSD and in-depth chemical composition analysis. A multi-phase thick-section S690QT HSS, containing a mixture of ferrite, tempered bainite and tempered martensite was investigated. The phase fractions were found to vary significantly through the thickness due to cooling rate gradients and elemental segregation in the plate’s mid-thickness. The slower cooling in the mid-thickness led to a higher ferritic content compared to the outer plate areas. Furthermore, in mid-thickness, segregation of elements such as Mo, Mn and Cr strongly influence the phase transformations, resulting in higher martensitic and lower ferritic content in enriched than in depleted zones.
9:10 AM
Ultrasonic Scattering in Two-phase Polycrystalline Materials: Showmic Islam1; Musa Norouzian1; Joseph Turner1; 1University of Nebraska-Lincoln
Typically, many of the polycrystalline materials found in nature and those created using different manufacturing processes consist of multiple phases. Careful nondestructive characterization of these materials is of fundamental importance. The work presented here aims to provide a better understanding of the propagation and scattering of elastic waves in two-phase solids. Traditional ultrasonic theories are modified such that they can be applied to synthetic three-dimensional microstructures to determine the scattering responses numerically. Different volume fractions of the two-phase polycrystalline material of copper and iron (Cu-Fe) are considered for this study. DREAM.3D is used to simulate 30 realizations of synthetic microstructures representative of each volume fraction. Ultrasonic phase velocity and attenuation values are calculated for all the synthetic microstructures. The synthetic results are then compared with the microstructures of samples made from binary mixtures of pure copper and pure iron. (Research supported by AFRL under prime contract FA8650-15-D-5231.)
9:30 AM
Effects of Microstructural Features on the Crack Initiation Mechanism in AA6451 during Three-point Bending: Yung Suk Yoo1; Sazol Das2; Richard Hamerton2; Josh Kacher1; 1Georgia Institute of Technology; 2Novelis Inc.
Aluminum alloys’ low density and high strength-to-weight ratio makes them an ideal candidate for automotive industries. The variety of alloying elements and processing produces complex microstructures that deform heterogeneously under different loading conditions. To better understand the failure mechanism of aluminum alloys, this work explores the effects of secondary phase particles and grain boundaries on crack initiation mechanism during bending.In this study, AA6451, used as outer door panels in cars, was subjected to three-point bending to simulate hemming with inner door panels. Post-mortem scanning electron microscopy, focused ion beam (FIB) cross-section, and electron backscatter diffraction were combined to identify defects that exhibit localized deformation leading to cracking and determine the chronology of the crack initiation process. FIB lift-out specimens were extracted from regions of interest, and transmission Kikuchi diffraction and scanning transmission electron microscopy were used to study the evolution of defect structures that accompany localized deformation.
9:50 AM
Applying Stereological Characterisation to the Solidification Structure of Single Crystal Alloys to Deduce the 3D Macroscopic Solid/Liquid Interface Shape: Joel Strickland1; Bogdan Nenchev1; Karl Tassenberg1; Samuel Perry1; Gareth Sheppard1; Hongbiao Dong1; 1University of Leicester
Single crystals are a continuous unbroken solid crystal lattice with no grain boundaries. They find a wide range of applications, from semi-conductors, optoelectronics, to applications in aerospace engines. Primary spacing is a key phenomenon during single crystal solidification as it determines microsegregation, defect formation, and final material performance. In this work, an automatic, standardised, and comprehensive stereological single crystal characterisation methodology is applied to two sections of a CMSX-10® Ni-base superalloy bar. The Shape-Limited Primary Spacing methodology rapidly and accurately determines dendritic centres, packing pattern, and local primary spacing distribution within these bulk microstructures. Using the relationship between the radial variation of local primary spacing and isotherm curvature, the SLPS methodology has enabled the post-mortem reconstruction of the 3D macroscopic solid/liquid interface shape.
10:10 AM
Development of Onboard Temperature Monitoring System for Axlebox in Railway Bogie: Jeongguk Kim1; 1Korea Railroad Research Institute
The axlebox temperature monitoring system in real time of railway vehicle bogie was developed. The bogie of a railway vehicle is a device responsible for driving the vehicle. For stable operation of wheels and axles, bearings are mounted on the axlebox. In order to detect the wear or abnormal conditions of the bearings, the temperature of the bearing area is measured at the wayside, and the condition diagnosis of the bearing is performed by monitoring the occurrence of abnormal heat generation. In this study, for temperature measurement of the bearings, a device was built to monitor temperature distribution in axlebox area in real time using a small infrared camera. In addition, a thermocouple was mounted on the same site to perform a comparative analysis of the results obtained from the thermal image. It was found that it was in good agreement with the temperature values obtained through the thermocouple.
10:30 AM
Influence of Morphology on Ultrasonic Scattering: A Theoretical Study: Showmic Islam1; Musa Norouzian1; Joseph Turner1; 1University of Nebraska-Lincoln
Nondestructive quantification of the microstructural organization with ultrasonic scattering techniques can help predict the mechanical performance of a component. Three-dimensional digital microstructures are used to investigate the scattering of mechanical waves within a numerical framework. These synthetic microstructures can either be voxel or tessellation based. In this study, the variation of ultrasonic scattering is predicted for microstructures of different morphologies for a nickel (Ni) polycrystalline material. The difference in ultrasonic properties due to various morphologies such as the Voronoi, and Laguerre tessellations and the synthetic microstructure created by DREAM.3D is calculated using 30 realizations. The results show that the differences in the two-point statistics and ultrasonic responses for different morphologies becomes more significant for a wider distribution of grain sizes. Finally, the importance of such differences with respect to grain-size estimation from ultrasonic measurements will be discussed. (Research supported by AFRL under prime contract FA8650-15-D-5231).
10:50 AM
In Situ Study of High Temperature Oxidation of Alloys Using Ambient Pressure X-ray Photoelectron Spectroscopy: Richard Oleksak1; John Baltrus1; Tao Liu1; Rafik Addou2; J Trey Diulus2; Gregory Herman2; Bharat Gwalani3; Arun Devaraj3; Ömer Doğan1; 1National Energy Technology Laboratory; 2Oregon State University; 3Pacific Northwest National Laboratory
Ambient pressure X-ray photoelectron spectroscopy (AP-XPS) is a relatively new technique that enables analysis of the composition and chemical environment of a material surface under relatively high gas pressures (>1 mbar). When combined with a heating stage, this allows for study of high-temperature surface reactions in situ. While AP-XPS has been applied extensively to study many types of functional materials, it has received little attention for what appears to be an obvious application in the realm of structural materials: high-temperature oxidation of alloys. Herein we present AP-XPS results of chromia-forming model alloys exposed to O2, low-purity CO2, and high-purity CO2 at 1 mbar and temperatures up to 530 °C. Post-exposure TEM and APT were also used to provide complementary analysis of the oxidized surfaces at the near-atomic scale. The results are discussed with emphasis on the oxidation mechanisms revealed by AP-XPS that were inaccessible by other existing characterization techniques.
11:10 AM
Characterization of Reactive Metallic Nanolayers through High-speed Imaging: Ali Bagheri Behboud1; Feyza Kazanc1; Sezer Ozerinc1; 1Middle East Technical University
Reactive metallic nanolayers are nanolaminated structures composed of alternating layers of two metals. Thermally or mechanically-induced mixing of these pure metal layers results in the formation of an intermetallic alloy through an exothermic reaction. The associated high heat released causes a self-propagating combustion behavior. The high energy density and self-propagating nature of the metallic nanolayers make them suitable for challenging joining applications. In this work, we characterized the combustion behavior of free-standing Ni/Al nanolayers as well as nanolayers attached to a substrate through high-speed imaging and differential scanning calorimetry. Our findings indicate that the presence of a substrate and its thermal properties affect the combustion behavior considerably. The results show that the thermal properties of the parts to be joined are critical for the quality of the nanolayer-assisted joining process.