...Roland Mücke; Klaus Rau Modern heavy-duty gas turbines operate under hot gas temperatures that are much higher than the temperature capability of nickel superalloys. For that reason, advanced cooling technology is applied for reducing the metal temperature to an acceptable level. Highly cooled...

... or for thermal cyclic tests. The former generally provides data for creep of the superalloy and the overall performance, and the later provide data for thermal barrier coating (TBC) spallation as a function of thermally grown oxide thickness, surface roughness, temperature, and thermal mismatch between...

...) Loria , E. A. , 1992 , “ Recent Development in the Progress of Superalloy 718 ,” JOM 1047-4838 , 44 ( 6 ), pp. 33 – 36 . Ezugwu , E. O. , Bonney , J. , and Yamane , Y. , 2003 , “ An Overview of the Machinability of Aeroengine Alloys ,” J. Mater. Process. Technol. 0924...

... costs. These components are cast from either Co-based solid solution superalloys such as FSX-414, or Ni-based gamma prime precipitation strengthened superalloys such as IN738. The nominal compositions of FSX-414 and IN738 are Co–29.5Cr–10.5Ni–7W–2Fe (max)–0.25C–0.012B and Ni–0.001B–0.17C–8.5Co–16Cr...

...Daniel McGuire; Xiao Huang; Doug Nagy; Weijie Chen Wide gap brazing (WGB) is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. However, it has been shown that WGB joints of nickel-based superalloys suffer from reduced ductility...

...Roland Mücke; Piyawan Woratat The performance of heavy duty gas turbines is closely related to the material capability of the components of the first turbine stage. In modern gas turbines single crystal (SX) and directionally solidified (DS) nickel superalloys are applied, which, compared...

...Britta Laux; Sebastian Piegert; Joachim Rösler High-temperature diffusion brazing is a very important technology for filling cracks in components from single-crystalline nickel-base superalloys as used in aircraft engines and stationary gas turbines: Alloys, which are similar to the base material...

... and (ii) it provides an additional resistance to oxidation. It was the objective of this study to develop an understanding of the role of platinum in bond coats of the diffusion-type deposited on a nickel-based superalloy. Two Pt-containing bond coats were included in the study: (i) a platinum-aluminide...

...Britta Laux; Sebastian Piegert; Joachim Rösler A new high temperature brazing technology for the repair of turbine components made of single crystalline nickel based superalloys has been developed. It allows the repair of single crystalline parts by producing an epitaxially grown braze gap within...

... been used to explain the dwell fatigue of titanium alloys and high temperature creep-fatigue interactions in Ni-base superalloys under tensile cyclic creep rupture, compressive cyclic creep rupture, and tension/compression-hold strain controlled cyclic test conditions. Referring to Eq. 7 , in order...

...M. Aghaie-Khafri; S. Farahany Creep degradation of an IN738C superalloy after long-term thermal exposure in an atmospheric furnace was investigated by means of accelerated creep tests. Experimental observation showed that the minimum creep rate increased by increasing the exposure time or exposure...

...Doug Nagy; Xiao Huang Repair of after-service gas turbine hot section superalloy components provides considerable saving in life-cycle cost of engines. Whereas a number of methods have been used in the past to repair these superalloy components, wide gap brazing technology has provided a practical...

.... In this study, tension-torsion biaxial TMF tests have been performed between 450 ° C and 870 ° C on a Ni-base directional solidified superalloy. Strain ratio ϕ was defined as shear strain range, Δ γ , to normal strain range, Δ ε , and ϕ varied from 0 to infinity. The “Blade wave form,” which simulated...

...Stephen Schoonbaert; Xiao Huang; Scott Yandt; Peter Au Co-base superalloys are commonly used for vanes and parts of the combustion chamber in gas turbine engines. The Co-base superalloys are primarily solid solution strengthened and have good resistance to hot corrosion, creep, and thermal fatigue...

... to predict the FCG rate and, hence, life in single crystal components subject to mixed-mode fatigue loading. 16 10 2006 17 10 2006 26 03 2008 crack-edge stress field analysis discs (structures) fatigue cracks finite element analysis fracture mechanics nickel alloys superalloys...

... been developed from cyclic test data on smooth and notched specimens made of a ferritic 1.5CrNiMo rotor steel. The analytical formulations obtained have then been applied to test data on the nickel base superalloy MAR-M247 CC showing a good agreement between prediction and measurement. Moreover...

...Nagaraj K. Arakere; Erik Knudsen; Gregory R. Swanson; Gregory Duke; Gilda Ham-Battista Single-crystal superalloy turbine blades used in high-pressure turbomachinery are subject to conditions of high temperature, triaxial steady and alternating stresses, fretting stresses in the blade attachment...

... present a numerical and experimental investigation of 3D stress fields and evolution of slip sector boundaries near notches, using double-notched tensile specimens of a single-crystal superalloy, which has a fcc crystal structure. A 3D linear elastic finite element model that includes the effect...

.... Long-term test results will be presented for commercially available wrought austenitic stainless steels and nickel-base superalloys exposed at 1300°F and 1400°F in environments containing various levels of water vapor. 16 June 2003 01 October 2002 01 March 2003 24 11 2004...

...N. K. Arakere, Associate Professor, Hot section components in high-performance aircraft and rocket engines are increasingly being made of single crystal nickel superalloys such as PWA1480, PWA1484, CMSX-4, and Rene N-4 as these materials provide superior creep, stress rupture, melt resistance...