PDF Publication Title:
Text from PDF Page: 151
strength of as received silicon nitride is 86.6 ksi, while the failure strength of the coated silicon nitride is 81.4 ksi. The fracture origin for both samples, as marked in the figure 9, is from the silicon nitride surface as judged by the fracture mirror and crack branching pattern. The magnitude of fracture mirror radius is also same for both the samples, ~ 300μ each. (a) (b) Figure 9: (a) Fracture surface of as received silicon nitride that failed at 86.6 ksi in bend test. (b) Fracture surface of as silicon nitride coated with the compliant laer and Si that failed at 81.4 ksi in bend test The fracture mirror radius is directly proportional to crack size from which the fracture initiated [17]. The local stress at failure is hence inversely proportional to the square root of fracture mirror radius. Since the failure strength determined from testing and the fracture mirror sizes are nearly the same for both samples shown in figure 9, the local stresses at failure are also the same. This implies that the bond coat system on silicon nitride does not contribute to any additional local stresses and isolates the interaction of residual stress in silicon layer from preexisting flaws in silicon nitride. It is thus demonstrated that the bond coat system neither creates a different critical flaw population nor does it affect the stress intensity factor associated with original flaw population present in the as received material. SCALE-UP EFFORTS IN PREPARATION OF COATING DEMONSTRATIONS As outlined earlier, coating of integral components requires non-line-of-sight coating methods. Slurry based coating techniques offer the promise of being low cost and versatile with respect to composition unlike most vapor routes such as CVD. Unfortunately, the slurry coating technology to make relatively thick and high density coatings for environmental protection is not mature. Reference 18 lays out the important principles of slurry development with focus on EBCs. It is clear from the discussion captured in references 18 and 19 that one of the most critical parameters that govern the ability to obtain uniform and crack free coatings of the desired thickness is slurry rheology. The references cited explain the importance and methodology of pH selection, binder selection, and binder content as a function of starting powders. In the current study, the principles of slurry stabilization and viscosity control outlined in references 18 and 19 were utilized to optimize slurries for dip coating. The composition of interest was the ceramic interlayer discussed in the previous section. Slurry viscosity was critically dependent upon pH, binder and solid loading. It was also found that coating coverage and uniformity at the coupon level could not be used to guide slurry optimization as component geometries played an important role in determining coating quality as will be obvious in the following discussion. Also, dip coating trials on prototype components plays an important role in the development of uniform coatings and offers the opportunity for a number of sub-scale tests needed to validate the coating before engine tests. Efforts at scale-up were focused on two classes of components: (1) single SN282 blades for burner rig tests, and; (2) integral turbine components (integrally bladed rotors and integral vane rings) in order to closely understand the challenges of coating complex geometries. Dip coating the single silicon nitride blades helped in optimization of slurries and designing fixtures to hold and manipulate the components during the dip coating process. Figure 10a is a picture of an EBC coated blade before a burner rig testing. The blade was burner rig tested in the UTRC facility described in reference 10. The flame from the burner impinged upon the blade and the material temperature on the leading edge was in excess of 2400F (1315 °C). The approximate hot time was 2 minutes and the blade was subsequently cooled for 1 minute. As is seen from figure 10b, there was no observable damage after 50 thermal cycles. Similar burner rig testing will be used to qualify the coating as the final coating architecture and process is down selected. 150 Copyright © 2007 by ASMEPDF Image | ADVANCED MICROTURBINE SYSTEMS Final Report for Tasks 1 Through 4 and Task 6
PDF Search Title:
ADVANCED MICROTURBINE SYSTEMS Final Report for Tasks 1 Through 4 and Task 6Original File Name Searched:
AdvancedMicroturbineSystems_924484.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)