Education:

• MS, Metallurgical Engineering,University of Tennessee, Knoxville, TN, May 1989
  
• BA, Chemistry, Saint Vincent College, Latrobe, PA, May 1982.
  

Research Experience:

• 1993 through present: Research Engineer, Ceramic Surface Systems Group
  
  • Ceramic fiber-reinforced-ceramic matrix composite materials
    • Technical Task Leader for the Department of Energy’s Continuous Fiber Ceramic Composites Program, Supporting Technologies Task - Supporting Technologies was established to conduct the more fundamental or generic research in the areas of composite design, materials characterization, test method development, and performance-related phenomena.
    • Chemical Vapor Infiltration - Incorporation of various ceramic fibers; Nicalon and other SiC fibers, Nextel^TM and other alumina-based fibers, AVCO monofilaments, carbon fibers and ceramic whiskers and platelets into ceramic matrices: e.g. SiC, Si₃N₄, BN, TiB₂, and B₄C; Si-C-O compounds; and carbon, employing chemical vapor infiltration and polymer-precursor techniques. Efforts included the development and improvement of the forced-flow, thermal-gradient CVI (FCVI) process and equipment for the rapid densification of fibrous preforms (disks, plates, and tubes) with ceramic matrices. Includes mechanical property evaluation and elevated-temperature oxidation of the aforementioned continuous fiber ceramic composites.
    • Fiber-Matrix Interfaces - Characterization and modification of the fiber-matrix interface in ceramic composite materials including deposition of modifying interlayers to individual filaments or fibrous preforms, instrumented indentation for measuring interfacial forces, and development of a simple tensile test to determine interfacial shear strengths. Detailed studies of the effects of interface coating properties on the mechanical properties and fracture behavior of fiber-reinforced ceramic composites revealed the ability to alter behavior through changes in fiber coating microstructure and composition. Advanced interface coatings with improved oxidation resistance have been developed and/or examined including vapor deposited boron nitride, boron-doped carbon, silicon-boron nitride and porous silicon carbide, and oxidation-inhibited carbon from novel liquid precursors.
  • Metal Matrix Composites: Small Arms Projectiles
    • Non-Lead Bullets - Development of non-toxic replacement materials for lead in small arms projectiles employing powder metallurgy techniques. Composite simulants for lead were developed by binding heavy hard metals such as tungsten together with soft light metals such as tin or zinc. The density and properties of the bullets with the non-lead composites mimic those of lead producing no change in ballistic performance. The impact behavior of the composite materials has been altered through composition, starting materials, and processing. In addition, the density of the composite simulant can be altered to adjust the dimensions of a projectile or weight distribution within a bullet, either enhancing or diminishing stability and performance. This technology was transferred from the laboratory to industry in one year.
    • Chemical vapor deposition of ceramic and metal coatings
    • Chemical Vapor Deposition - Deposition of thin ceramic and metal films and coatings employing hot- and cold-walled reactors. Compositions including SiC, Si, TiN, TiC, TiSi₂, Ti₃SiC₂, TiB₂, WC, W, Mo, Mo_xSi_y, Si₃N₄, B, BN, B₄C, HfC, ZrC, and Al₂O₃. Applications include wear and erosion resistant coatings, damage-resistant, non-reflective optical coatings for infrared wavelengths, and corrosion protection.
    • Thermodynamics - Thermodynamic analysis of the chemical vapor deposition of ceramic materials utilizing thermoequilibrium computer codes (SOLGASMIX-PV, etc.). Involved determination and estimation of thermodynamic properties of complex compositions, interpretation of the data, and application of information to the deposition of materials, i.e. selection of reactants, concentrations, pressures, temperature, etc.
    • Equipment Design - Design and modification of CVD furnaces (resistive and induction heating) and other equipment including computer control of complex deposition systems. Many of the CVD systems required complicated gas handling equipment such as mass flow controllers, liquid vapor sources, solid sublimation or direct halogenation sources, temperature and pressure control, and unique combinations of said to produce the conditions necessary to deposit the coatings of interest.
    • Corrosion and Erosion Resistant Coatings - Deposition of coatings for oxidation protection of carbon-carbon composites and wear and erosion applications. Coatings examined include carbide, nitride, and boride based multiphase or "composite" layers in the Si-Mo-N, Si-Mo-C, Si-B-C, Si-Cr-C, Si-Cr-N, Al-Mo-N, and Si-C-Mo-S systems; and functionally-gradient materials (graded-composition coatings) in the Si-C and Si-B-C systems.

1981 through 1983: Technical Support Staff/Co-op Student , Kennametal, Inc., Latrobe, PA

• Ceramic development
  • Si-Al-O-N - Development of sialon (Si-Al-O-N) based ceramic materials (Kyon 2000) for cutting tool and wear applications, from silicon nitride powder production to manufacturing, e.g. pressing and sintering.
• Carbide powder processing and development
  • Tungsten Carbide Cermets - Bonded-carbide materials research and development in coordination with production and manufacturing. Mixing, blending, milling, pelletizing, pressing, extrusion and sintering of various metal carbide powder blends for cutting tools and other hard material applications.
• Analytical services
  • Characterization and chemical analysis of raw and processed materials in support of research and development activities and production. Responsibilities included: atomic absorption analysis of carbide and other metallic powders, x-ray diffraction, x-ray fluorescence analysis together with development of alternate glass compositions for dissolution of metals and compounds for standards and general sample preparation.

Professional Societies:

• American Ceramic Society
• American Defense Preparedness Association
• American Society for Engineering Education, Co-Chair, 1995 National Educators Workshop on Materials Science and Engineering
• American Society of Metals , Composite Materials Committee
• Materials Research Society, Symposium Chair, 1995 Fall Meeting, edited Proceedings; Symposium Chair, 1998 Fall Meeting
  

Publications:

• Authored or co-authored > 80 papers and other documents, 3 book chapters, and edited one proceedings.
  Complete list available upon request
  

Patents:

• 5,760,331 Non-lead, environmentally safe projectiles and method of making same
• 5,300,322 Molybdenum enhanced low-temperature deposition of crystalline silicon nitride
• 5,075,160 Ceramic fiber reinforced filter
• 4,929,328 Titanium diboride ceramic fiber composites for Hall-Heroult cells
• 4,895,108 CVD apparatus and process for the preparation of fiber-reinforced ceramic composites

Group Members

Surface Processing and Mechanics Group