Advances in Multi-Principal Elements Alloys X: Alloy Development and Properties: Thermal and Other Properties
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Alloy Phases Committee, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Peter Liaw, University of Tennessee; Michael Gao, National Energy Technology Laboratory; E-Wen Huang, National Chiao Tung University; Jennifer Carter, Case Western Reserve University; Srivatsan Tirumalai; Xie Xie, FCA US LLC; Gongyao Wang, Globus Medical

Thursday 8:30 AM
March 3, 2022
Room: 251A
Location: Anaheim Convention Center

Session Chair: Baldur Steingrimsson, Imagars LLC; Yong-Jie Hu, Drexel University; Benjamin Adam, Oregon State University

8:30 AM  Invited
A Comparison of the Sliding Wear of Carbon-doped Fe40.4Ni11.3Mn34.8Al7.5Cr6 and CoCrFeMnNi High Entropy Alloys with 316 Stainless Steel at 293 K and Cryogenic Temperatures: Ian Baker1; F.E. Kennedy1; Y. Ye1; J. D. Bonilla Toledo1; R.R. White1; R.L. Barry1; X. Guo2; S.P. Ringer3; H. Chen3; W. Zhang4; Y. Liu4; M. Song4; 1Dartmouth College; 2School of Materials Science and Engineering, Central South University; 3The University of Sydney; 4Central South University
    We have recently designed and built a cryogenic pin-on-disk wear tester for performing sliding wear tests either dry at ~110 K or under liquid nitrogen at ~77 K. This presentation will compare the results of wear tests of the f.c.c. high entropy alloys carbon-doped Fe40.4Ni11.3Mn34.8Al7.5Cr6 and equiatomic CoCrFeMnNi with those for 316 stainless steel. Tests were performed against zirconia in both ambient air and argon, and dry and in liquid nitrogen at cryogenic temperatures. The effect of different sliding velocities will also be described. After wear testing, the zirconia disk was examined using optical profilometry, whereas the worn pins and wear debris were characterized using profilometry, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectrometry, electron backscattered diffraction, X-ray photoelectron spectroscopy, and atom probe tomography. The results are explained in terms of the oxidation behavior and the contact temperature. Work supported by National Science Foundation grant 1758924.

8:50 AM  Invited
Thermodynamics and Phase Transformations in Refractory Complex Concentrated Superalloys: Eric Lass1; 1University of Tennessee-Knoxville
    Refractory-based complex concentrated superalloys (CCSs) have received significant research attention in recent years because they show great promise as next-generation high temperature materials, supplanting conventional Ni-based superalloys which have reached their fundamental limits due to precipitate solvus and alloy melting temperatures. Such alloys are typically BCC, and may be strengthened by ordered B2 precipitates, leading to a two-phase microstructure that looks remarkably similar to their Ni-based cousins. However, the thermodynamic higher-order nature of the BCC-B2 transformation, compared to first-order for FCC-L12, leading to fundamental differences between the two systems. This presentation will explore how these differences affect microstructural development, such as the observed “inverted” B2-BCC structure. Design strategies to overcome such barriers to practical application are discussed from a thermodynamic perspective. Critical gaps in fundamental scientific understanding hindering future development CCSs are also discussed.

9:10 AM  
Antimicrobial Properties of a Multicomponent Alloy: Anne Murray1; Daniel Bryan1; David Garfinkle1; Cameron Jorgensen1; Eric Lass1; Easo George2; Ying Yang2; Philip Rack1; Tom Denes1; Dustin Gilbert1; 1University of Tennessee; 2Oak Ridge National Lab
    High-traffic touch surfaces are a vector for disease propagation, motivating the need to develop materials that are rapidly self-sanitizing and active against a range of pathogens. A variety of metals have been shown to be highly bioactive; developing an alloy of several bioactive metals may result in a broad-spectrum sanitizing surface which functions by a range of mechanisms. However, many bioactive metals are immiscible, including our targets CuCoAg. Using an entropy stabilization paradigm, alloys of CuCoAgNi were prepared as a metastable alloy, then annealed. Structural and bioactivity testing was performed on several compositions, both as-prepared and annealed. Testing included surrogate microorganisms for human pathogens in several major classes, including enveloped and non-enveloped viruses and gram-positive and negative bacteria. The results emphasize the critical role of the microstructure and copper composition on achieving a sanitizing effect.

9:30 AM  Invited
NOW ON-DEMAND ONLY - Development of Multi-principal-element Alloys and the Applications in Dissimilar Metals Welding: Jianxun Hu1; Peiyong Chen2; Xuesong Fan2; John Bohling2; Chanho Lee3; Peter Liaw2; Carl Lundin2; A. M. M. Abdelmotagaly4; Zhenzhen Yu4; 1Honda Manufacturing & Development, Americas; 2University of Tennessee; 3Los Alamos National Laboratory; 4Colorado School of Mines
    Dissimilar metals joining has become increasingly important in developing multi-material vehicle body structure to achieve lightweight strategy. However, welding of dissimilar metals, i.e. aluminum and steel sheet metals in automotive industry, has been challenge due to the inherent discrepancies in the metallurgical and physical properties between the two metals. The formation of the intermetallic compounds prohibits attaining the satisfactory welds and promotes the corrosion. High entropy alloys (HEAs) have been developed and applied in reducing and even eliminating the formation of the intermetallics between the dissimilar metals when using resistance spot welding (RSW) and arc welding methods. High-entropy alloys (HEAs), with 5 or more principal elements in equiatomic ratio, were first found to successfully prohibit the formation of intermetallics between the aluminum and steel, and provide satisfactory welding strength. The microstructure and tensile property of the weld were investigated with the different thickness and composition of the HEAs.

9:50 AM Break

10:10 AM  
Spinodal Decomposition in Multi-component Alloys: Shalini Koneru1; Kamalnath Kadirvel1; Yunzhi Wang1; 1The Ohio State University
    Multi-principal element alloys (MPEAs) with multiple phase microstructures have a great potential for future engineering applications. Researchers attributed the multi-phase microstructures observed in well-known MPEA systems such as TiZrNbTa, AlMo0.5NbTa0.5TiZr, Al0.5NbTa0.8Ti1.5V0.2Zr, and Fe15Co15Ni20Mn20Cu30 to spinodal assisted phase transformation pathways. The critical features of spinodal decomposition such as spinodal temperature and initial concentration modulations direction in the compositional space could play a vital in the development of multi-phase MPEAs with desired microstructures. Therefore, the present study develops a formulation to utilize CALPHAD databases to explore spinodal decomposition in well-known MPEA systems. It is seen that many MPEA systems are conditionally unstable against concentration modulations along a specific direction in the compositional space. The predictions agree well with available experimental observations.

10:30 AM  Invited
Compositionally Complex Ceramics (CCCs): Jian Luo1; 1University of California, San Diego
    A series of equimolar five-component MB2 [Scientific Reports 2016], MB [Scripta 2020], M3B4 [JAC 2021], MB4 [JECS 2020] and MB6 [JECS 2021], borides, perovskite [Scripta 2018], fluorite [JECS 2018] and pyrochlore [Scripta 2020] oxides, silicides [JMat 2019] and aluminides [Science Bulletin 2019] have been fabricated in the single-phase, dense, bulk form in our lab, which demonstrated the diversity of high-entropy ceramics (HECs). Furthermore, we proposed to extend HECs to “compositionally complex ceramics (CCCs)” [JECS 2020; JMS 2020], where non-equimolar compositions can outperform their equimolar counterparts and other complexities (e.g., short- and long-range cation ordering) can be further introduced. Further expansion include the discoveries and investigation of dual-phase HECs/CCCs [JECS 2020] and order-disorder transitions in many-cation (>10 components) single-phase HECs/CCCs [Acta 2021 and unpublished results]. We have also observed the formation of single-phase HECS/CCCs in a crystal structure that none of the individual components is stable, thereby suggesting new possibilities.