Fatih GÜNDÜZ 030060144 7th week Answers (Part 2)

Ion Plating : (13:51 5.4.2011) (Previous)(Better)
Ion plating is another surface treatment process that has recently attracted a great deal of attention. Ion plating also possesses many advantages as compared to conventional coating techniques. Therefore, although the present study has concentrated on ion implantation, it is appropriate to compare this proces with ion plating There are also striking diferences. Thusi each method is likely to find its own regime of application.
Ion plating is carried out in a gaseous electrical discharge in which the substrate to be plated is the cathode. The discharge is created by an applied ptential of 500 to 5000 volts. The prmary component of the gaseous enviroment is usually an inert gas, most often argon. Atoms of material to be plated are introduced into the gas by evaporation are ionized before striking the substrate. The small protion og evaporant are drawn to cathode by the electric field and scattering effects. Deposition rates can approach 25micrometer/min, but are acoomonly about a tenth of this amount.
(National Research Council (U.S.), Committee on Ion Implantation and Competing New Surface Treatmen Technologies Robert Wiliam Keyes, Ion Implatation as a New Surface Treatment Technolohy: Report, pg:19)

Ion Plating : (New)(Surface Treatment Process)
Ion Plating is an atomistic deposition process that utilizes continuous or periodic bombardment of the substrate and depositing atoms of film material by atomic-sized energetic particles. The bombardment prior or deposition sputter cleans the surface. Bombardment during deposition is used to obtain good adhesion, densify the depositing material, aid in chemical reactions, modify residual stress, and otherwise modify the structure, morphology, and properties of the depositing film or coating. It is important, for best result, that the bombardment the continuous between the cleaning and the deposition portions of the process in order to maintain an atomically clean interface.
(Handbook of Physical Vapor Deposition (PVD) Processing, Donald M. Mattox, p.301)


Slurry infiltration : (12:55 5.4.2011) (Previous)
Continous-fiber composites are made b allowing fibers from a spool to pass through a glass powder slurry(containing water and a water-soluble acrylic binder), winding the slurry-impregnated fibers onto the sides of a hexagonal prism(mandrel or take-up drum), cutting up the flat unidirectional tapes from the mandrel, stacking up the pieces (plies) in the correct orientation, burning out the stack to remove the binder and hot pressing the stack at a temperature above the working temperature of the glass. This process is known as slurry infiltration.
(Deborah D. L. Chung, Compostie MAterails: Functional Materials for Modern Technologies, pg:47)

Slurry infiltration : (New)(Better)(Manufacturing Process)
Slurry infiltration is the most prevalent process used to make glass and glass-ceramic composites, mainly because the processing tremperatures used for glass and glass-ceramics are lower than those used for crystalline ceramics. The melting point of crystalline ceramic is so high, than even fibers with interfacial coatings would be either dissolved or severaly degraded. Another problem is the large temperature differance between extremely high processing temperatures and room temperature, which can result in shrinkage and matrix cracking. In addition, crystalline ceramics heated past their melting points have such high viscosities that the infiltration of performs is very difficult, if not impossible.
(Manufacturing Technology for Aerospace Structural Materials, Flake C. Campbell, p.474)