Advances in Surface Engineering: Session I
Sponsored by: TMS Surface Engineering Committee
Program Organizers: Rajeswaran Radhakrishnan, Faraday Technology Inc; Timothy Hall, Faraday Technology Inc; Michael Roach, University of Mississippi Medical Center; Sandip Harimkar, Oklahoma State University; Tushar Borkar, Cleveland State University; Rajeev Gupta, North Carolina State University; Bharat Jasthi, South Dakota School of Mines & Technology
Monday 2:00 PM
October 10, 2022
Room: 328
Location: David L. Lawrence Convention Center
Session Chair: Rajeswaran Radhakrishnan, Faraday Technology, Inc; Andrew Moran, Faraday Technology, Inc
2:00 PM
Electrochemical Finishing of Mo Feedhorn Arrays: Huong Le1; Timothy Hall1; Stephen Snyder1; E. Jennings Taylor1; Maria Inman1; 1Faraday Technology
This paper will discuss recent developments toward the demonstration of a process to electrochemically finish the feedhorn arrays produced with Mo by EBM additive manufacturing. Specifically, we will discuss developments toward achieving optimal electrochemical processing conditions, surface finish, nominal tooling, and performance. Unlike conventional surface finishing processes that either use media or machine tools to physically modify the surface, electrochemistry can be used as a non-contact flexible approach, to finish hard to reach surfaces such as the internal channels of refractory materials that may be inaccessible to conventional processes. This paper will focus on pulse/pulse reverse electrofinishing processes developed by Faraday Technology and the technique to scale this approach to functional parts of interest.
2:20 PM
Electrochemical Machining of Steel and Refractory Alloys: Andrew Moran1; Tim Hall1; Stephen Snyder1; Victor Alderman1; Brian Skinn1; 1Faraday Technology Inc.
Electrochemical machining (ECM) is an established manufacturing technique that possesses several advantages relative to traditional machining including: 1) applicability to hard and difficult to cut materials, 2) no tool wear, 3) high material removal rate, 4) smooth bright surface finish, and 5) production of parts with complex geometry. This talk will summarize research in machining non-linear through-holes in metallic substrates via multi-step ECM with a modified apparatus to suit tubular workpieces. Results from the ECM of non-linear holes in tubular steel workpieces will be presented, demonstrating the capability to achieve through-hole shapes not possible with conventional machining. This talk will also discuss recent efforts in the ECM of surface channels in Ta and Ta10W alloys through the application of pulse-reverse voltages.
2:40 PM
In Situ Formation of Titanium Carbide during Surface Modification of Steel via TIG Arcing: Nilesh Paraye1; Prakriti Ghosh1; Sourav Das1; 1Indian Institute of Technology Roorkee
In this work in-situ grown titanium carbide/Fe matrix surface composite coating were manufactured by Tungsten inert gas arcing. The results showed that the microstructure of modified surface consist of titanium carbide in martensite matrix via in situ formation. Further the shape and size of the carbide were evaluated using carbon replica method and characterized in Transmission Electron Microscope with STEM imaging mode. The shape of the precipitate consists of cubical structure. Thermodynamic prediction of the fusion zone was evaluated using Thermo-Calc software. Thermal profile of the molten pool suggests that the cooling rate and thermal gradient were fairly high to transform into the martensite phase. Significant increase in hardness and improvement in wear behavior of the modified region was observed with the change in chemical composition and the phase transformation.
3:00 PM Cancelled
Wear Behaviour of Surface Modified Carbide Free Bainitic Steel: Ajeet Singh Rajput1; Nilesh Paraye1; Sourav Das1; 1Indian Institute of Technology Roorkee
The microstructure of contacting surface has a profound influence on sliding wear behaviour. This paper aimed to understand the effect of microstructure generated after surface modification of carbide-free bainitic steel (CFB) by Tungsten Inert Gas (TIG) arcing on wear in dry sliding contact. Effect of change in sliding distance at the constant applied load on wear mechanisms and other surface and subsurface modifications have been studied. The wear mechanism was changed from primarily adhesion to ploughing and micro-cutting. The results showed improved wear resistance of surface modified CFB steel in comparison to as received CFB steel. But crack formation tendency on surface and subsurface enhanced as compared to as received CFB steel. Compared to as received CFB steel, the surface modified CFB steel microstructure offered a higher resistance against the formation of brittle white etching layer during the sliding wear.
3:20 PM Break
3:40 PM
Surface Modification of Low Carbon Steel via In Situ Formed Tantalum Carbide through Tungsten Inert Gas Arcing: Sachin Balbande1; Nilesh Paraye1; Sourav Das1; 1IIT Roorkee
AISI 8620 is generally low carbon steel which is used in many applications such as bearing, camshaft, fastener, gear and so on. These applications require good surface hardness, toughness and wear resistance. Introducing in situ formation of carbide is one of the ways to improve properties through the tungsten inert gas arcing (TIG) process. Microstructural characterization reveals that the modified surface consists of martensite in lathe form and irregular shapes of precipitates. X-ray diffraction (XRD) shows the presence of the TaC phase formed on a modified surface. Energy dispersive spectroscopy (EDS) mapping shows tantalum and carbide distribution at the precipitate location. The selected area electron diffraction (SAED) pattern confirms that precipitate has a cubic structure. The modified surface has been marked as an increment in hardness as compared to the base metal.