Editor's Note: This is the latest in a series of profiles provided by the Hydro Research Foundation that highlight potential future members of the hydroelectric power industry and their accomplishments.
The Hydro Research Foundation is actively supporting graduate students to conduct research related to conventional and pumped storage hydropower. These students are funded through the Department of Energy’s Water Power Program and industry partners through a two-year grant.
Thomas Gualtieri's journey through life and school has taught him that he wants to research, innovate, and overall make a positive impact on the world. By working towards advancing hydroelectric technology for the nation’s future, he can achieve this and more. Gaultieri is currently a first year graduate student in the School of Mechanical and Materials Engineering at Washington State University, pursuing his graduate education in Mechanical Engineering. He started studying engineering his second year of college after switching from a business program. Since that time he has always wanted to do research in hopes of it making a difference in this world and clean energy has been a great interest to him.
Gaultieri has lived in Washington State his whole life, and has benefited from the power that U.S. dams have produced. To dat, he has published one journal paper, one conference proceeding and one accepted book chapter. He hopes to continue this trend and publish many more papers for the work he does on advancing the hydroelectric industry.
Gaultieri completed this thesis in April with the support of Dr. Amit Banydopadhyay and has been working with, Gerry Russell at Weir American Hydro and Steve Wenke with Avista Utilities. The title of his thesis is "Direct Laser Deposition of Porous Structures and Gradient Metal-Ceramic Composite Coatings." Direct laser deposition is an additive manufacturing technique capable of producing complex geometries, bond different materials, repair broken parts, and add protective coating. In the present study it is used to make micro-porous scaffolds and apply protective vanadium and niobium carbide coatings. Micro-porous metal filters are a difficult thing to make but are required for many applications.
In this study it was hypothesized that laser engineering net shaping (LENS) could be used to make porous Ti6Al4V scaffolds with an interconnected micro-porous structure. This proved to be true with cylinders made to have 15.9% porosity, and a pore size less than 100μm. These structures were made by only altering processing parameters, which yielded a scaffold with obstructed random pore interconnectivity. The scaffolds had a compressive strength of 645-556MPa and martensitic like α′ grains. Another study was done to apply hard niobium and vanadium carbide surface coatings to stainless steel. The objective was to used LENS to deposit stainless steel coatings with added carbides to eventually make a gradient coating with increased protective qualities. Parts that have suffered material loss from abrasive wear or cavitation could have material added back as well as add a protective coating at the same time. Compositions ranging from 5% to 100% of the carbides were mixed with stainless steel.
The coatings were then deposited on a stainless steel 304 substrate individually, as well as in a series to make a gradient structure. These coatings all increased hardness, wear resistance, and 100%VC significantly increased the materials resistance to damage from abrasive water. The carbides integrated into the SS304 matrix on the grain boundaries making a metal ceramic composite. These precipitates left residual stress in the structure which increased the hardness and wear resistance. The study proved that the addition of these carbides did increase the protective qualities and could make a gradient coating with properties tailored to the user’s preference.
Thomas will be finishing his research with the Foundation in May and is actively seeking employment in the industry. To connect with Thomas or learn more about the Research Awards Program please email firstname.lastname@example.org or visit the website www.hydrofoundation.org