Advances in Surface Engineering III: Session I
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 8:30 AM
March 17, 2021
Room: RM 37
Location: TMS2021 Virtual
Session Chair: Bharat Jasthi, South Dakota School of Mines & Technology; Tushar Borkar, Cleveland State University
8:30 AM
Surface Modification by In-situ Grown VC Reinforced Composite Layer on Steel Substrate Using TIG Arcing Process: Nilesh Kumar1; Prakriti Ghosh1; Sourav Das1; 1Indian Institute of Technology Roorkee
Tungsten inert gas arcing as a surface treatment process with the dilution of the base material can be used for developing surface composite. In this work, in-situ grown vanadium carbide/Fe matrix surface composite coating was manufactured by Tungsten inert gas arcing. The microstructure of the modified surface consists of vanadium carbide in the martensite matrix via in situ formation. Further, the shape and size of the vanadium carbide were evaluated using a carbon replica method and characterized in Transmission Electron Microscope with STEM imaging mode. The shape of the precipitate consists of a cubical structure. Thermodynamic prediction was evaluated using Thermo-Calc software. The thermal profile of the molten pool suggests that the cooling rate and thermal gradient were fairly high. A significant increase in hardness and improvement in wear behavior of the modified region was observed owing to the in situ formation of vanadium carbide in the martensite matrix.
8:50 AM
Effect of Potassium Hydroxide (KOH) Additives on Corrosion Behavior of Coatings Formed by Plasma Electrolytic Oxidation (PEO) Method on the Titanium Substrate: Navid Attarzadeh1; Maryam Molaei2; Kazem Babaei2; Arash Fattah-alhosseini2; 1University of Texas at El Paso; 2Bu-Ali Sina University
We studied formation of ceramic PEO coatings from aluminate-based electrolyte with KOH additives in 3, 4 and 5 g/l concentrations on the pure titanium substrate. The scanning electron microscopy (SEM) showed that the most compact and uniform PEO coating was formed with 4 g/l KOH additive, where despite increasing the number of porosities, the pore sizes declined. Due to excessive conductivity, the strongest sparks could form in electrolyte with 5 g/l KOH additive, which could cause creation of bigger pore sizes, and hence diminishing corrosion resistance. Using electrochemical impedance spectroscopy (EIS), we deduced PEO coatings with 4 g/l additive demonstrated the higher corrosion resistance with the best surface characteristics. X-ray diffraction analysis revealed a presence of TiAl2O5 phase with a mixture of rutile and anatase phases.
9:10 AM
Electroplated Powder to Improve Particle Adhesion in Cold Spray Applications: Gwendolyn Bracker1; Elizabeth Hodges1; Madeline Scott1; V. Champagne2; Robert Hyers2; 1University of Massachusetts; 2Cold Spray Innovations International
Cold spray is a processing technique in which powder particles are accelerated toward a substrate on which they deposit and build a wrought coating. In this process it is essential to balance the velocity of the particle, the properties of the particle, and of the substrate; otherwise, the particles may either fail to deposit or, may erode the substrate. Current work is exploring approaches that would allow for harder particles to be deposited on the surface of more ductile substrate without eroding the substrate. One approach to accomplish this is electroplating a softer coating on the hard powder. However, electrodeposits readily form a continuous layer binding the particles into a matrix, rather than uniformly coating the powders. A novel approach to electroplating has been successful with several different combinations of coatings and powders.