Advances in Multi-Principal Element Alloys II: Alloy Design and Manufacturing
Sponsored by: TMS Structural Materials Division, TMS Functional Materials Division, TMS: Mechanical Behavior of Materials Committee, TMS: Alloy Phases Committee
Program Organizers: Peter Liaw, University of Tennessee; Michael Gao, National Energy Technology Laboratory; E-Wen Huang, National Yang Ming Chiao Tung University; Jennifer Carter, Case Western Reserve University; Srivatsan Tirumalai; Xie Xie, FCA US LLC; James Brechtl, Oak Ridge National Laboratory; Gongyao Wang, Globus Medical
Tuesday 2:30 PM
March 21, 2023
Room: Aqua D
Location: Hilton
Session Chair: Peter Liaw, The University of Tennesee; Xinghang Zhang, Purdue University
2:30 PM Keynote
2023 Institute of Metals Lecture/Robert Franklin Mehl Award: Metallurgical Engineering to Materials Science and Engineering: Evolution of a Profession and TMS: Carl Koch1; 1North Carolina State University
I joined TMS in1957 as an undergraduate student in Metallurgical Engineering at Case Institute of Technology. Since then, our profession and TMS have evolved. My own evolution through my career will be given as an example of the changes in our profession and the need for lifelong learning. When I was an undergraduate “steel was king”. Most of the research projects when I was in graduate school were on steel. However, as the “age of silicon” started in the 1960’s, this changed. Industrial laboratories such as General Electric and DuPont had a history of using multidisciplinary research to solve materials problems. The first university department of materials science and engineering began at Northwestern University in 1959. This talk will discuss the nature of a profession, the history of the metallurgical/materials professions, the associated professional societies, and the history of engineering and materials engineering education.
3:00 PM Keynote
Challenges in the Synthesis and Processing of Complex Concentrated Alloys: Calvin Belcher1; Sakshi Bajpai1; Benjamin MacDonald1; Diran Apelian1; Enrique Lavernia1; 1University of California Irvine
In the past two decades, a wide variety of CCAs have been developed as evidenced by the doubling of CCA publications each year since discovery. In some systems, constituents not typically mixed in conventional alloys can pose new challenges to fabrication of these CCAs. To date, few processing techniques have been developed for the industrial fabrication of CCAs. Rather, conventional laboratory scale processing techniques have enabled exploration of CCA compositions. In this study, the grand challenges to industrial production of CCAs, such as impurity element reactions, miscibility of dissimilar elements, sustainable constituent element sources, and properties of CCAs in the molten state are outlined. Possible solutions to these grand challenges are discussed in context of the University of California, Irvine Center for Complex and Active Materials (CCAM) where efforts are focused on leveraging collaborations across metallurgy, computational modeling, and high-resolution microscopy to study interfaces and atomistic phenomena in CCAs.
3:30 PM Invited
Computational Studies of Interfaces in High Entropy Ceramics.: Sam Daigle1; Jon Hagelstein1; Donald Brenner1; 1North Carolina State University
In conventional alloys, stresses at grain boundaries, free surfaces, dislocations and related defects can attract solute atoms and in some cases induce ordering. Using first principles calculations and analytic modeling, we have been exploring whether interfaces and defects in high-entropy carbides induce similar chemical ordering, and if this ordering changes the interfacial stability and mechanical properties. Of particular interest are energies to form twins, whether ordering around dislocations increases (or decreases) the barrier for motion, and the effects of ordering on grain boundary energy, de-cohesion, and inter- versus trans-granular fracture.
3:50 PM Invited
Additive Manufacturing of Multi-principal Element Ni Alloys with Nanoprecipitates: Bo Yang1; Benjamin Stegman1; Zhongxia Shang1; Jack Lopez1; William Jarosinski2; Xinghang Zhang1; 1Purdue University; 2Praxair Surface Technologies Inc.
Multi-principal element (MPE) alloys have widespread industrial applications due to their high strength and radiation tolerance. Here we show that additive manufacturing can be employed to produce fully dense NiCrFe and NiCrW MPE alloys with nanoprecipitates. Scanning electron microscopy studies identified well aligned arrays of carbide nanoprecipitates along dislocation cell walls in NiCrW alloys. Transmission electron microscopy studies revealed that carbide nanoprecipitates formed several aligned orientation relationships with the matrix. In comparison, oxide nanoprecipitates formed in the NiCrFe MPE alloys. In situ tension studies showed the oxide nanoprecipitates improved the high temperature performance of the MPE alloys. These nanoprecipitates also changed the deformation mechanisms of MPE Ni alloys. This study suggests that additive manufacturing may open a new avenue to produce advanced MPE alloys for applications in extreme evironments.
4:10 PM Break
4:30 PM Invited
Unique Magnetism, Hydriding and Irradiation Behaviors of Some Multi-Principal Element Alloys: Tongde Shen1; 1Yanshan University
We have found that multi-principal CoFeNiAlSi alloys have such exceptional properties as a high yielding strength of 1,636 MPa, a high electrical resistivity of 68.0 μΩ cm, a high saturation induction of 1.24 Tesla, and a low coercivity of only 59.7 A/ m. In particularly, their total power loss can be lower than that of conventional Fe-Si alloys. In addition, we have found micron-/nano-scale hierarchical structures in a cast multi-principal VCrTiNi alloy, which has been often considered as a coarse-grained hydrogen storage alloy. The TiNi nanoprecipitates plays an essential role in the hydrogen storage behavior. Finally, we have found the enhanced phase stability of TiNi intermetallic compound nanoprecipitates in an irradiated multi-principal VCrTiNiPd alloy. The underlying mechanisms for these unique magnetism, hydriding, and irradiation behaviors are analyzed. Our work may give a guidance for designing new multi-principal element alloys with improved magnetism, hydriding, and irradiation performances.
4:50 PM
Recent Developments of Body-centered-cubic (BCC) High-entropy Alloys: Lia Amalia1; Xuesong Fan1; Hugh Shortt1; Baldur Steingrimsson1; Fangfei Liu2; Yong Zhang2; Yanfei Gao1; Peter Liaw1; 1University of Tennessee; 2University of Science and Technology Beijing
High-entropy alloys (HEAs) are alloys with five or more principal elements in equimolar or near-equimolar ratios. Compared to HEAs with other structures, BCC HEAs have stronger lattice-distortion effects, which leads to more significant solid-solution strengthening. The BCC structures in HEAs are more common to be found in refractory HEAs (RHEAs). Atypical as compared to conventional BCC metals, some BCC HEAs are found to have edge dislocations after deformation. BCC RHEAs are known to have low ductility. Recently, by conducting a series of heat treatments, the microstructure of the precipitates could be manipulated, and the plasticity of Al0.5NbTa0.8Ti1.5V0.2Zr could be enhanced. High-throughput design coupled with laser additive manufacturing has made faster design, fabrication, and characterization processes possible. Machine learning has also been utilized to predict high-temperature strengths in HEAs. BCC RHEAs have been investigated to have the potential to be used in nuclear, high-temperature, and biomedical applications.
5:10 PM
Unraveling Hydrogen Embrittlement of Model High Entropy Alloys: Michela Geri1; Menglei Jiang1; Cemal Tasan1; 1MIT
Hydrogen Embrittlement (HE) has been extensively studied in different metallic materials including high entropy alloys (HEAs); however, many fundamental questions remain open and need to be addressed to guide the design of alloys with improved resistance. Our group has recently developed a class of model FeMnCoCr systems that show double transformation (fcc to hcp to bct) and can be designed with variable stacking fault energy by carefully adjusting the Mn content. In this talk we investigate the possibility of using these metastable model HEAs that enable switching among dislocation-dominant, twinning-induced plasticity (TWIP) or transformation-induced plasticity (TRIP) modes, to systematically study the consequences on HE resistance. We do so by combining in-situ SEM characterization with hydrogen charging, imaging and mechanical testing at different length scales (from nanoindentation to tensile testing). Exploring these effects in a model system will help provide guidelines for HE-resistance in other TRIP- or TWIP-assisted alloys.
5:30 PM Invited
Interplay of Lattice Distortion and Ordering in Refractory High-entropy Alloys: Wei Chen1; Geroge Kim1; Chenyang Li1; Peter Liaw; Peter Liaw2; 1Illinois Institute of Technology; 2University of Tennessee
The material-design strategy of combining multiple elements in near-equimolar ratios has spearheaded the emergence of high-entropy alloys (HEAs), an exciting class of materials with exceptional engineering properties. While random mixing has been widely assumed in multi-principal element solid solutions, both experimental and computational evidence suggests short-range ordering (SRO) exists in many solid-solution HEAs. We employed an integrated first-principles and experimental approach to understanding the interplay of lattice distortion and SRO in the refractory NbTaTiV and NbTaTiVZr HEA systems. The existence of SRO produces distinct lattice distortion features in these HEAs and affects their mechanical properties. The fundamental understanding of SRO and lattice distortion is coupled with high-throughput first-principles calculations and machine learning to design refractory high-entropy alloys.
5:50 PM Invited
Structural and Compositional Inheritances of Intermetallic Phases in High-entropy Alloys: Ruei-Chi Tsai1; Keng-Che Chang1; An-Chen Fan1; Daniel Miracle2; Ming-Hung Tsai1; 1National Chung Hsing University; 2AF Research Laboratory
High entropy alloys (HEAs) strengthened by intermetallic (IM) phases can have attractive mechanical performances. However, the design of IM phases in HEAs is challenged by the lack of systematic knowledge on these phases. Here, statistical analyses were used to investigate relationships between IM phases in HEAs and their binary/ternary counterparts. Both structural and compositional considerations of this analysis aimed to determine how the IM phases in an HEA were affected by their counterparts in the binary/ternary subsystems of that alloy, and if other factors dominate in the formation of these IM phases. Our findings suggest that IMs in HEAs were closely related to binary/ternary IMs that could be formed in the subsystems of the alloys. Such similarities were called structural and compositional inheritances and their importance will be discussed.