Deposit microstructure

Tassopoulos, M. Relationships between particle deposition mechanism, deposit microstructure and effective transport properties . PhD Thesis, Yale University, USA (1991). 

Kuroda, S., Deudo, T., and Kitahara, S. (1995) Quenching stress in plasma sprayed coatings and its correlation with the deposit microstructure. J. Therm. Spray Technol, 4 (1), 75-84. 

Preparation of Epitaxially Grown Cr-Si-N Thin Films by Pulsed Laser Deposition Microstructure... 

AU other carbon steel, low-intermediate, and high-aUoy steels, ferritic steels Base metal Deposited weld metal and heat-affected zone (See Note 1) 2. Except when conchtions conform to Note 2, the material shall be heat-treated to control its microstructure by a method appropriate to the material as outlined in the specification applicable to the product form and then impact-tested. (See Note 1.) Deposited weld metal and heat-affected zone shall be impact-tested. 

Microstructural examinations revealed that branched cracks originated at shallow pit sites on the external surface. The pits, which may have formed during idle periods from differential oxygen concentration cells formed beneath deposits, acted as stress concentrators. The transverse (circumferential) crack orientation and the localization of cracks along just one side of the tube revealed that bending of the tube was responsible for the stresses involved. 

A hyper-eutectic alloy containing, say, 50% Sb starts to freeze when the temperature reaches the liquidus line (point a in Fig. 20.39). At this temperature pure pro-eutectic Sb nucleates as the temperature continues to fall, more antimony is deposited from the melt, and the composition of the liquid phase moves down the liquidus line to the eutectic point. When this is reached, the remainder of the melt solidifies. The microstructure of alloys of eutectic composition varies somewhat with alloy system, but generally consists of an aggregate of small particles, often platelets, of one of the phases comprising the eutectic in a continuous matrix of the other phase. Finally, the microstructure of the hypereutectic 50% Sb alloy already mentioned... 

Since multiple electrical and optical functionality must be combined in the fabrication of an OLED, many workers have turned to the techniques of molecular self-assembly in order to optimize the microstructure of the materials used. In turn, such approaches necessitate the incorporation of additional chemical functionality into the molecules. For example, the successive dipping of a substrate into solutions of polyanion and polycation leads to the deposition of poly-ionic bilayers [59, 60]. Since the precursor form of PPV is cationic, this is a very appealing way to tailor its properties. Anionic polymers that have been studied include sulfonatcd polystyrene [59] and sulfonatcd polyanilinc 159, 60]. Thermal conversion of the precursor PPV then results in an electroluminescent blended polymer film. 

In the previous sections, it was shown how thermodynamic and kinetic considerations govern a CVD reaction. In this section, the nature of the deposit, i.e., its microstructure and how it is controlled by the deposition conditions, is examined. 

England, K. M., and Mazunder, J., Kinetics and Microstructure of Laser Chemical Vapor Deposition of Titanium Nitride, SPIEProc., 2703 552-562 (Feb. 1996)... 

Delplancke-Ogletree, M. R, Monteiro, O. R., and Brown, I. G., Preparation of TiC and TiC/DLC Multilayers by Metal Plasma Immersion Ion Implantation and Deposition Relationship Between Composition, Microstructure and Wear Properties," Materials Research Society Symposia Proceedings, Voi.438,1997,p.639. 

Sol-gel techniques have been successfidly applied to form fuel cell components with enhanced microstructures for high-temperature fuel cells. The apphcations were recently extended to synthesis of hybrid electrolyte for PEMFC. Although die results look promising, the sol-gel processing needs further development to deposit micro-structured materials in a selective area such as the triple-phase boundary of a fuel cell. That is, in the case of PEMFC, the sol-gel techniques need to be expanded to form membrane-electrode-assembly with improved microstructures in addition to the synthesis of hybrid membranes to get higher fuel cell performance. 

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