Advances in Surface Engineering IV: Session III
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Surface Engineering Committee
Program Organizers: Arif Mubarok, PPG; Bharat Jasthi, South Dakota School of Mines & Technology; Tushar Borkar, Cleveland State University; Mary Lyn Lim, PPG Industries; Rajeev Gupta, North Carolina State University
Tuesday 2:30 PM
March 1, 2022
Room: 210C
Location: Anaheim Convention Center
Session Chair: Rajeev Gupta, North Carolina State University
2:30 PM
Corrosion Behavior of Shear Extruded Mg-3Si Magnesium Alloy: Role of Mg2Si Fragmentation and Grain Refinement: Vikrant Beura1; Vineet Joshi2; Kiran Solanki1; 1Arizona State University; 2Pacific Northwest National Laboratory
Alloying addition of silicon to magnesium alloys, such as Mg2Si phases, has been observed to improve the creep response. However, being electrochemically noble compared to magnesium matrix, these phases can induce micro galvanic corrosion in magnesium alloys. To achieve an overall improvement in these trade-off properties, a noble solid-phase processing technique namely the friction extrusion has been used to process Mg-3wt%Si (Mg-3Si) alloy from the feed cast ingot. The cast Mg-3Si alloy, which was found to composed of α-Mg + Mg2Si eutectics and Mg2Si phase was observed to undergo grain refinement and fragmentation of Mg2Si phases by the friction extrusion process. Further, an increase in the cathodic kinetics and a decrease in polarization resistance of friction extrusion alloys were observed. Lastly, to understand underlying mechanism by deconvoluting the effect of grain size and second phase fragmentation, pH-dependent electrochemical studies were performed on Pure Mg and Mg2Si along with Mg-3Si samples.
2:50 PM
Microstructural, Mechanical, and Corrosion Properties of Pulsed Laser Deposited Hexagonal Boron Nitride Nanofilms: Venkata A.S. Kandadai1; Venkata Gadhamshetty1; Bharat K. Jasthi1; 1South Dakota School of Mines & Technology
The main objective of this work is to investigate the microstructure, mechanical properties, and corrosion behavior of various substrates modified with nanolayers of hexagonal boron nitride (hBN) using pulsed laser deposition (PLD) process. Microstructural characterization and phase identification were performed using scanning electron microscopy and X-ray diffraction. Raman spectroscopy was employed to characterize the quality of hBN coatings. The surface roughness of the coatings was analyzed using Atomic force microscopy. The mechanical properties, such as the hardness and modulus of the hBN nanofilms, were characterized using the nanoindentation technique. The electrochemical properties of coated and uncoated substrates were carried out using tafel plots and electrochemical impedance spectroscopy measurements. The resultant microstructure and mechanical properties of the films were correlated to the PLD process variables.
3:10 PM
HVOF 316L and C276 Metal Cladding for Corrosion Protection: Juliane Ribeiro da Cruz1; Sanjay Sampath1; 1State University of New York at Stony Brook
Stainless steels and nickel alloys are often selected as structural materials for industrial machinery exposed to harsh corrosive environments due to their elevated corrosion resistance. To minimize material costs, this study assesses the viability of cladding mild steel with 316L stainless steel and C276 nickel alloys for corrosion protection. Coatings were processed by high velocity oxygen-fuel (HVOF) with oxygen rich, neutral and fuel rich flame stoichiometries. Microstructure characterization was performed by X-ray diffraction analysis, and optical and scanning electron microscopy. Electrochemical polarization scans were conducted in deionized water and 3.5 wt% NaCl salt solution. Result show that processing of these materials with fuel rich flame causes more oxidation, chromium removal from solid solution and inferior corrosion performance, even in fully dense coatings. Coatings processed with oxygen rich flame performed similarly to bulk material, suggesting that HVOF cladding of mild steel is a cost-effective alternative to improve corrosion resistance.
3:30 PM
Simultaneous Effects of MC Carbide Formers on Hardness of Wear Resistant Overlays by Design of Experiments and Machine Learning: Jing Li1; Bing Cao1; Haohan Chen1; Leijun Li1; 1University Of Alberta
Optimizing the composition and improving the wear-resistant properties of complex alloys have always been difficult by traditional, one-variable-at-a-time, methods. Here we propose a Design of Experiments and machine learning strategy to design alloys with a targeted hardness in the overlay system containing MC-type primary carbides and eutectic matrix (austenite and M7C3-type carbides) with various Nb, Ti, and V combinations. An interactive contour map has been built to correlate the chemical composition and microhardness of the overlay through a simple generalized linear model. Three chemical compositions with a predicted hardness of 600 to 610 HV have been used to verify and refine the model. The proposed strategy provides an efficient way to design overlays with targeted hardness without exhausting experiments.
3:50 PM Break
4:10 PM
Strong Covalent Bonding between PMMA/Zn-Mg Alloys Using Grafting-from Technique for Biomedical Applications: Oumaima Laghzali1; Alia Diaa2; Flavien Mouillard1; Nahed El Mahalawy2; Genevieve Pourroy1; Patrick Masson1; Heinz Palkowski3; Adele Carrado1; 1IPCMS - CNRS, Université de Strasbourg, France; 2German University of Cairo, Cairo, Egypt; 3IMET, Clausthal University of Technology, Clausthal-Zellerfeld, Germany
Zinc (Zn)- magnesium (Mg) alloys are suitable candidates as biodegradable materials for surgical implants. Their biocompatibility has been previously studied through cell compatibility, cytotoxicity, dynamic blood clotting and other genetic and bacterial test. However, they still face disadvantages due to their strength and degradation velocity in vivo. In literature you find information to enhance their corrosion resistance using coatings such as poly(methyl methacrylate) (PMMA) through spin-coating technique lacking of a thick covalent bond between the polymer film and the alloy. To overcome this issue, we developed an approach using grafting-from technique. PMMA was coated on Zn-Mg alloys and its effect on corrosion resistance and biocompatibility was evaluated. A dense, stable and biocompatible PMMA film with a thickness up to 5 µm that achieved complete surface coverage with a hydrophobic behavior, was made possible. Presented data will include ATR-FTIR, EDAX-SEM , AFM, and XRD results, while cross-sections were characterized using SEM.
4:30 PM
Towards the Tuning of the Degradation Behaviour of Pure Biodegradable Zn by Laser Texturing: Carlo Biffi1; Jacopo Fiocchi1; Sofia Gambaro1; Ausonio Tuissi1; 1CNR - National Research Council
The present work concerns the surface modification of biodegradable pure Zn for controlling the degradation rate in the prospective of its use for temporary implants. The material, produced by cold rolling, was laser textured using two different ranges of pulse durations, nanosecond and femtosecond, for tuning the surface morphology and microstructure. The laser process was studied by varying different process parameters like power, scan speed and hatch spacing for both the laser sources. The effect of these parameters was correlated to the surface morphology, characterized with scanning electron microscope images, X-ray diffraction and e3D profilometry. Once selected the most promising laser conditions, the degradation performances of the laser textured surfaces were analyzed and compared with the ones of the untreated material. It was found that the laser surface modification can tune the surface degradation behaviour with respect with the base material, due to the induced morphology, microstructure and oxides produced.
4:50 PM
Unraveling the Roles of Thickness, Crystallinity and Composition of Powder Passivation Layers during Cold Spraying of Aluminum Powder: Cameron Crook1; Seyed Saeidi1; Diran Apelian1; Daniel Mumm1; Lorenzo Valdevit1; 1University of California Irvine
Cold spray of aluminum powders is heavily influenced by the native passivation layer which forms under ambient conditions. Under humid atmospheric conditions at room temperature, this passivation layer readily thickens, increasing the critical adhesion velocity while reducing bonding and deposition efficiency. For structural repair applications, bonding is critical; however, it is unclear whether passivation layer crystallinity, thickness, and composition or some combination thereof is principally responsible. Here we perform surface modification to grow Al powder passivation layers of varying crystallinity, thickness and composition. High resolution electron microscopy and single particle impact experiments directly correlate the passivation layer microstructure and critical adhesion. Further examination is performed using density functional theory calculations of the mechanical properties of alumina polymorphs including amorphous and hydrated systems and empirical shock relations. These results give credence to thickness and crystallinity being the main drivers of increases in critical adhesion velocity.