Bulk Metallic Glasses XVIII: Alloy Design and Development
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Peter Liaw, University of Tennessee; Yanfei Gao, University of Tennessee-Knoxville; Hahn Choo, University of Tennessee; Yunfeng Shi, Rensselaer Polytechnic Institute; Robert Maass, Federal Institute of Materials Research and Testing (BAM); Xie Xie, FCA US LLC; Gongyao Wang, Globus Medical
Thursday 2:00 PM
March 18, 2021
Room: RM 7
Location: TMS2021 Virtual
Session Chair: Kefu Yao, Tsinghua University; Qiaoshi Zeng, Center for High Pressure Science and Technology Advanced Research
2:00 PM
Atomistic Characterization and Modeling of Corrosion in Al-based Amorphous Metals: Jia Chen1; Wenjun Cai1; 1Virginia Polytechnic Institute and State University
Amorphous metals and alloys have attracted increasing interest in various industries due to their high hardness, fracture strengths, elasticity limit, and corrosion resistance. While traditional precipitation-strengthened alloys typically suffer from the strength-corrosion resistance tradeoff, amorphous metals often exhibit excellent corrosion resistance, largely owing to the lack of secondary phases, the absence of grain boundary, and the retention of high alloying content in homogenous solid solution. In this study, the effects of manganese (Mn) on the corrosion resistance of amorphous Al-Mn was studied using experiments and atomistic simulation. It was found that Mn addition enhanced the corrosion resistance of Al without participating in the surface oxidation. The selective dissolution of Mn was believed to increase the free volume at the metal/oxide interface to facilitate the formation of a denser, thinner oxide layer with closer to stoichiometry composition and enhanced barrier characteristics against corrosion.
2:20 PM
Synthesis of Bulk Metallic Glass-alumina Composites with Intertwined Dendritic Structure: Je In Lee1; Amy Wat2; Chae Woo Ryu3; Jinyeon Kim3; Eun Soo Park3; Robert Ritchie2; 1Pusan National University; 2University of California, Berkeley; 3Seoul National University
Bulk metallic glasses (BMGs) have been of significant interest as potential structural materials due to their high strength and large elastic strains. Zr-based BMGs exhibit excellent wettability with conventional ceramics, which indicates that BMGs are suited for filler materials to produce metal-ceramic hybrid materials with hierarchical architecture. In this study, we utilize the dendritic growth of ice crystals in a thermal gradient to assemble an alumina with dendritic pore architecture, which is then infiltrated with glass-forming alloy melt to make a bioinspired, micrometer-scale, intertwined BMG-alumina composite. The microstructures of the composites, prepared at various infiltration temperatures, are examined to show how the chemical reaction between the BMG-forming melt and alumina affects the interfacial bonding between the constituents. The BMG composite exhibits ultra-high strength with exceptional relative compressive strength, far better than ceramic particulate BMG composites.