|Solution Precursor Plasma Spray |
|Eric H. Jordan, University of Connecticut|
12:10 PM, CCR 201
Solution precursor plasma spray (SPPS) is a relatively new process where liquid chemical precursors are injected directly into a DC arc plasma gun traditionally used to make coating from powder feed stocks in a process called air plasma spray. The ceramic materials are synthesized, melted and deposited in a single step. Such a process has several important advantages including very rapid compositional exploration since new compositions can be made by different mixing ratios in the preparation of the solutions. Because the solution provides the input materials as molecularly mixed solutions and splat cooling is very rapid (106 Co/s), very fine two phase microstructures and metastable materials can be made. In addition, by control of the injection process semipyrolized materials may be included in the deposits which upon heating shrink and produce shrinkage cracks highly desirable for thermal barrier coatings. By different injection arrangements the cracks can be eliminated and dense coating can be made. The chief disadvantage of the process is that significant energy is needed to evaporate the solvent and adequate heating is a constant challenge. In this presentation, the basic operation of the SPPS process will be explained and specific example applications will be shown, including high performance thermal barrier coatings, the production of dense Ti02 bioactive coatings and recent attempts to make nano scale two phase ceramics. Finally, an example will be presented where solution spray was not successful and suspension and chemically synthesized powders were used instead. There is a clear need for continued improvement of the precursors used for this process. Achieving adequate cation loading is a continuing challenge.
Eric Jordan - High Temperature Mechanical Testing and X-Ray Mechanics Lab
Research Areas: Mechanical behavior of materials with emphasis on high temperature materials, thermal barrier coatings, thermal spray processing and properties, and nano crystalline materials.
Professor Jordan is involved in the development of optical methods designed to nondestructively predict remaining life in thermal barrier coatings. His main current research is the development of methods for making coatings and powders by the new process of liquid precursor plasma spray. Materials currently being developed include thermal barrier coatings, dense ceramics, optical ceramics and fluorescing seed particles for fluid flow diagnostics. Dr. Jordan also has a graduate appointment in Chemical, Materials and Biomolecular Engineering Department, is a Fellow of ASME, a member of the academic Advisory Board to the DOE UTSR program and has served as an Associate editor for the ASME Journal of Engineering Materials and Technology.
Host: Bernard Kear, tel: 5-2245, email: firstname.lastname@example.org