Advances in Surface Engineering III: Session II
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Surface Engineering Committee
Program Organizers: Tushar Borkar, Cleveland State University; Arif Mubarok, PPG; Rajeev Gupta, North Carolina State University; Sandip Harimkar, Oklahoma State University; Bharat Jasthi, South Dakota School of Mines & Technology
Wednesday 2:00 PM
March 17, 2021
Room: RM 37
Location: TMS2021 Virtual
Session Chair: Praful Bari, ZF Group; Tushar Borkar, Cleveland State University
2:00 PM
Electropolishing of Bronze in Concentrated H3PO4: Geng Ni1; Choong-un Kim1; 1University of Texas at Arlington
Electropolishing is one of the most important way of surface engineering. It is used in the surface preparation of the Cu-Sn bronze for producing of Nb3Sn superconductor by interdiffusion. Bronze is used as a source of Sn and Nb-Sn reaction is induced by depositing Nb on the bronze. Therefore, bronze surface needs to be atomically clean and mechanically flat, which may be easily achieved by electropolishing. Spurred by such need, we have explored the electropolishing of Bronze (10%Sn) with various conditions. Our characterization indicates that electropolished bronze surface may form a double layer structure of the Sn containing compounds with cations from the electrolyte, and Sn4 exists as outside and Sn2 exists as inside layer. Further, surface profiling shows that the surface roughness is sensitively affected by specifics of electropolishing condition, both temperature and current density, probably because those factors affect etching rates of Cu-rich and Sn-rich phases differently.
2:20 PM
Enhancement of Liquid Metal Wetting by Patterning Particles on Oxide Surfaces: Jiyun Park1; Jason Nicholas2; Yue Qi1; 1Brown University; 2Michigan State University
Improvement of wettability of oxides by liquid metals is important to have a well-bonded interface in many fields, but many researchers have focused on changing either chemical additives or surface roughness. This work shows how both topographically and chemically patterned surfaces (i.e., nickel particle patterned oxide surface) affect the wetting and spreading of liquid silver (Ag) on oxide surfaces. Molecular dynamics (MD) simulations, using a force field fitted to density functional theory calculations, showed that the hexagonally patterned Ni particles on yttria-stabilized-zirconia surface enhanced the wetting area of Ag by 224% compared to the bare surface. For generalization, an analytical model was derived for describing the maximum enhancement in wetting area and was verified with MD simulations. Both the analytical model and MD results suggested the role of Ni patterns in wetting enhancement becomes more significant as the intrinsic wettability of a substrate gets worse.
2:40 PM
Magnetron Sputtered Micro-lattice Structures: Expanding the Materials Working Space of Lattice Materials: Alina Garcia Taormina1; Chantal Kurpiers2; Andrea Hodge1; Ruth Schwaiger3; 1University of Southern California; 2Karlsruhe Institute of Technology; 3Karlsruhe Institute of Technology, Forschungszentrum Juelich GmbH
Lattice materials have garnered great interest due to their ability to achieve unique combinations of properties linked to their carefully controlled and optimized topologies. Recent advances in multiphoton lithography has enabled fabrication of novel 3-D polymer nano- and micro-lattice structures that have the potential of populating previously unattainable mechanical property regimes. Further functionalization has been achieved through subsequent deposition of ceramic and metallic coatings via atomic layer deposition and plating techniques; however, such methods are limited to materials that undergo specific chemical reactions. Thus, magnetron sputtering, a technique that allows for the deposition of a nearly unlimited selection of metals, alloys, and ceramics can be utilized to further expand the synthesis space of these materials. Our work leverages inverted cylindrical magnetron sputtering, a novel coating approach that allows for an unprecedented 360° line-of-sight to develop a deeper understanding of the parameters that influence thin-film growth on complex 3-D topologies.
3:00 PM
Modifying Corrosion Performance of Plasma Electrolytic Oxidation (PEO) Coatings using Potassium Hydroxide (KOH) and Potassium Fluoride (KF) Additives: Navid Attarzadeh1; Maryam Molaei2; Arash Fattah-alhosseini2; 1University of Texas at El Paso; 2Bu-Ali Sina University
We investigated the effects of two additives on microstructures and corrosion performance of coatings produced using the PEO method on commercially pure titanium substrates. The surface morphology of coatings was examined using scanning electron microscopy (SEM). We found coatings prepared with KOH additives had a uniform and more compact structure. Although the number of surface pores was larger for PEO coatings with KOH additives, the average size of pores was shorter, and no crack was found on the surface. Using KF additives led to the formation of thicker coatings, however, these coatings showed a weaker affinity to the substrate. Both coatings were composed of TiO2 (rutile and anatase) and TiAl2O5 phases, while the anatase content was lower for coatings with KOH additives. We understood that KOH additives could result in formation of coatings with greater corrosion resistance, which was attributed to the formation of PEO coatings with modified surface characteristics.
3:20 PM
Nitriding-assisted Surface Enhancement of Multi-
principal Element Alloys: Yu-Hsuan Lin1; David Poerschke1; 1University of Minnesota
Multi-principal element alloys (MPEAs) comprise a large, flexible compositional space that enables tuning of their chemistry, structure, and properties. This superior characteristic can also be harnessed in developing surface-enhancement strategies to further improve their wear and corrosion resistance. This work focuses on the design of transition- and refractory-MPEAs, and the formation of a nitride surface layer and a compositionally graded interstitial solid solution layer by nitriding. Preliminary experiments involve gas nitriding nitride-forming pure metals, including Hf, Mo, Nb, Ta, Ti, and Zr, to investigate the influence of temperature, time, and nitriding potential on the growth kinetics of the nitrided zone. The results serve as a reference to a computational thermodynamics screening process to identify promising MPEAs for further study. This approach aims to efficiently test a wide range of compositions, and narrow down feasible ones that provide high strength and good surface durability after nitriding.
3:40 PM
Phase-field Approach on Modeling Wetting of Rough Surfaces: Dong-Uk Kim1; Michael Tonks1; 1University of Florida
Wetting property which results in the wetting states such as Wenzel or Cassie-Baxter states is one of key factor of surface engineering. The contact state is determined by capillarity reaction between fluids and surfaces, induced by the balance of interfacial tensions of the coinciding interfaces, as well as roughness of the surfaces with morphology in capillarity length scale, which hinders theoretical analysis of wetting phenomena due to its complexity. In this study, we propose a computational model to analyze wetting phenomena on rough surfaces using phase-field approach which is an interfacial tracking method capable of dealing with capillarity reactions on virtually arbitrary shaped surfaces interacting with viscous fluids. It was revealed that the model is capable of rendering both Wenzel and Cassie-Baxter contact states.
4:00 PM Cancelled
The Role of Particle Passivation Layers in the Critical Adhesion Velocity of Cold Sprayed Powders: Cameron Crook1; Lorenzo Valdevit1; Daniel Mumm1; Diran Apelian1; 1University of California, Irvine
Cold spray is a promising solid-state thermal spray process capable of producing wrought-like, compressively stressed coatings with low oxidation. However, its process complexity, namely the properties of the powder feedstock, has required arduous material-specific empirical optimization. One particularly poorly understood factor is the passivation layers of powder particles which, though only nanometers thick, significantly increase the critical adhesion velocity of high purity aluminum powders when exposed to high humidity environments; although, it is unclear whether the thickening, appearance of partial crystallinity, hydration, or some combination therein are principally responsible. Here, pristine high purity aluminum powders are carefully atomized and treated to obtain powder particles with controlled passivation layer thicknesses and compositions to determine the individual contributions of the aforementioned features. Passivation layers were characterized by a suite of analytical techniques, including X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, high-resolution transmission electron microscopy and single-particle impact imaging.
4:20 PM
Trace Element Distributions in Al-Zn Based Coating Alloys on Steel Substrates: Dongdong Qu1; Matthew Gear1; Nega Setargew2; Wayne Renshaw2; Stuart McDonald1; David StJohn1; David Paterson3; Kazuhiro Nogita1; 1The University of Queensland; 2BlueScope Steel Ltd; 3Australian Synchrotron
The 55Al-Zn-1.6Si alloy is widely used in hot-dip galvanizing to coat steel and displays a multilayered microstructure (steel substrate/intermetallic compound (IMC) layer/coating overlay) that offers protection from corrosion. Trace level (less than a few tens of ppm) V and Cr are hypothesized to influence the corrosion performance of the coated steel via localized segregation. This paper investigates the distribution of trace V and Cr using synchrotron X-ray fluorescence microscopy (XFM) and scanning transmission electron microscopy (STEM) and discusses the role of those trace elements in corrosion protection.