RESEARCH PROJECTS & PUBLICATIONS
Rolls-Royce University Technology Centre | Printing NanoEngineering Laboratory | Advanced Failure Analysis UTEP
Optimization of Ni-Based Superalloy
Turbine Disc Application
ROLLS-ROYCE UTC
I planned and conducted an experimental investigation on a novel Ni-based superalloy used for turbine discs in commercial aerospace turbine engines; the investigation proposed studying, analyzing, and improving the metallurgical-mechanical properties relationship of the novel superalloy.
I quickly adapted my knowledge to work in accordance with international standards, policies, and procedures while following all safety guidelines. I performed metallographic samples in preparation for in-depth microstructural characterization.
I utilized optical and scanning electron microscopy to identify and determine grain size, inclusion and/or voids, primary-to-tertiary precipitate sizes, HAZ, fusion zone, and weld line. In addition, I utilized electron backscatter diffraction to identify crystalline orientation, characterize grain boundaries, calculate grain boundary surface area, and quantify defects.
I performed mechanical testing on a grid of a cross-sectioned weld coupon, yielding a detailed microhardness profile. The results from each investigation were studied relative to each other, providing immense insight to the materials behaviour in specific welding processes.
As a result of my work, welding process parameters were tested to optimize the weld joints’ microstructure for improved performance; the study was performed by a colleague pursuing his doctoral degree.
Failure Analysis Investigation
Ruptured Natural Gas Pipeline
ADVANCED FAILURE ANALYSIS COURSE | UTEP
I worked alongside two colleagues on a failure analysis investigation of a ruptured, land-based, natural gas pipeline. Using non-destructive (NDE/T) technologies, specifically magnetic particle testing, my team and I found linear indications near the weld seam.
We utilized scanning electron microscopy (SEM) to study the fracture surface and microstructure directly beneath the area of interest; we concluded the primary fracture mode consisted of high volume fractions of transgranular cleavage and low volume fractions of transgranular microvoid coalescence.
In addition to identifying primary fracture mode, it was evidenced that within the weld seam was inadequate fusion.
To better understand the possible root cause(s) of crack initiation and propagation, our team utilized transmission electron microscopy (TEM) and found large amounts of martensitic-austenite (M/A) islands. Specifically, in steels, M/A islands are detrimental to the mechanical properties, significantly reducing ductility. Though this was a very intriguing finding, failure may have been a result of inadequate fusion along the weld seam.
Our findings were documented and published in the Journal of Failure Analysis and Prevention, available upon request.
Optimization of Curable Ink Rheology for Printing Technologies
PNE LAB | SEOKYEONG-UTEP COLLABORATION
I planned and conducted an in-depth investigation of ultraviolet light emitting diode (UV-LED) curable ink technology for use on flexible substrates for flexible electronic applications.
I experimented with various percent weights of UV-LED curable ink to improve the rheological properties for optimized transfer during lab-scale reverse offset roll-to-plate (RO-R2P) printing.
Though I was able to fine tune the ink to an optimum viscosity, and in theory optimize the printing parameters, I concluded that the transfer of ink to substrate via RO-R2P was not feasible; however, these solutions were successfully printed via traditional inkjet and fused deposition modeling (FDM) printing technologies.
My findings were documented and published in the Journal of Electronic Materials, available upon request.
Optimization of Contact Rolling Printing Methods via Contact Angle Manipulation
PNE LAB | SEOKYEONG-UTEP COLLABORATION
Worked under the guidance of the primary author to determine if controlling the contact angle throughout the various stages of the printing process would have a significant impact on the final products' resolution. Through trial and error, contact angle sequencing proved to be successful in producing patterns of 5 micrometers in resolution, approximately 8x improved resolution.
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Alongside this practical experience was an opportunity to participate in writing a scientific journal paper, resulting in co-authorship of the laboratory's work.