Download or read book Elevated Temperature Crack Growth Studies of Advanced Titanium Aluminides written by Srivathsan Venkataraman and published by . This book was released on 1987 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ordered intermetallic titanium aluminide Ti AL alloyed with niobium possesses attractive high temperature properties and moderate low temperature ductibility. Currently, its application is limited to static components in aircraft gas turbine engines. To extend their use to rotating components of turbine engines, better understanding of life limiting processes such as creep/fatigue crack growth and fracture is required. Phase I of this Air Force Small Business Innovative Research program involved investigation of fatigue crack growth in an alpha two titanium aluminide plus niobium alloy (titanium - 16 wt% aluminum - 10 wt% niobium) as a function of temperature and environment. Computer automated fatigue crack growth tests were conducted in both air and vacuum environments at temperatures ranging from room temperature to 1200 F (649 C). Two heat treatment conditions, namely, beta solution and alpha + beta solution resulted in coarse and fine grain materials, respectively, with varying alpha two morphology. Fractographic analyses were conducted for all test specimens.

Download or read book Elevated Temperature Crack Growth Studies of Advanced Titanium Aluminides written by and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ordered intermetallic titanium aluminide Ti AL alloyed with niobium possesses attractive high temperature properties and moderate low temperature ductibility. Currently, its application is limited to static components in aircraft gas turbine engines. To extend their use to rotating components of turbine engines, better understanding of life limiting processes such as creep/fatigue crack growth and fracture is required. Phase I of this Air Force Small Business Innovative Research program involved investigation of fatigue crack growth in an alpha two titanium aluminide plus niobium alloy (titanium - 16 wt% aluminum - 10 wt% niobium) as a function of temperature and environment. Computer automated fatigue crack growth tests were conducted in both air and vacuum environments at temperatures ranging from room temperature to 1200 F (649 C). Two heat treatment conditions, namely, beta solution and alpha + beta solution resulted in coarse and fine grain materials, respectively, with varying alpha two morphology. Fractographic analyses were conducted for all test specimens.

Download or read book High Temperature Fracture and Fatigue Crack Growth of a gamma based Titanium Aluminide written by Aindrea Leigh McKelvey and published by . This book was released on 1996 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth of Two Advanced Titanium Alloys at Room and Elevated Temperature written by TP. Albertson and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper provides fatigue crack growth information at low crack growth rates for two sheet titanium alloys: ?-21S, a ? alloy, and Ti-62222, an ? + ? alloy. Room (25°C) and elevated temperature (175°C) fatigue crack growth tests at two different stress ratios, R = 0.1 and 0.5, were performed. Effects of temperature and stress ratio were evaluated in order to study the complex interaction between fatigue, environment, and loading conditions. Crack-opening load was measured throughout the test from automated compliance measurements and was used to adjust fatigue crack growth data for crack closure. For ?-21S, fatigue crack growth rates were similar at 175 and 25°C at a stress ratio of 0.1, while crack growth rates were lower at 175 versus 25°C at a stress ratio of 0.5 for the same nominal ?K. Concepts associated with crack closure accounted for this as crack growth rates were found to be higher at 175°C than 25°C for both stress ratios when plotted as a function of ?Keff, showing a temperature dependency on crack growth rate. For Ti-62222, fatigue crack growth rates were comparable between 25 and 175°C for R = 0.5, but were different at R = 0.1 where crack closure was observed at 175°C. Fatigue crack growth behavior of these two titanium alloys was comparable for all loading and temperature conditions.

Download or read book Investigation of Crack Growth in Titanium Aluminide at Elevated Temperatures written by and published by . This book was released on 1988 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates crack growth at elevated temperatures in a titanium-aluminide alloy (Ti3Al). The objectives are to determine the creep crack growth characteristics and the applicability of linear cumulative damage modeling to Ti3Al alloy. All tests were conducted on compact tension specimens of Ti3Al under isothermal conditions. Sustained load tests were used to characterize creep crack growth behavior. A fatigue test and several hold-time tests were used to test the applicability of linear cumulative damage modeling. The linear elastic stress intensity factor, K, was used a correlating parameter for all the tests. A model was generated using baseline data from the sustained load and fatigue tests and compared with the hold-time tests. The test results showed that sustained load crack growth is insensitive to temperature. Crack growth rates for all tested temperatures were only a factor of five apart between the slowest and fastest growth rates. Keywords: Creep, Fatigue, Crack propagation, Titanium aluminide, Damage modeling, Thesis. (jes).

Download or read book Fatigue Crack Growth in Two Advanced Titanium Alloys Under Variable Amplitude Loading at Room and Elevated Temperature written by Andrew Leigh Veit and published by . This book was released on 1996 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Crack Growth in Titanium aluminide at Elevated Temperatures written by Aernest A. Staubs (CAPT, USAF.) and published by . This book was released on 1988 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Behavior of Titanium Aluminide Ti 25Al 25Nb written by SJ. Balsone and published by . This book was released on 1993 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack growth rate of an orthorhombic + beta titanium aluminide, nominally Ti-25Al-25Nb, was studied as a function of temperature (25 to 750°C), environment (air and vacuum), frequency (0.001 to 1.0 Hz), and superimposed hold times (1 to 1000 s) under computer-controlled constant Kmax testing conditions. In addition, fatigue crack growth rates from the near-threshold region to rates greater than approximately 10-7 m/cycle were determined at room and elevated temperatures. Results show that the fatigue crack growth rate exhibits a combination of cycle- and time-dependent behavior and is sensitive to environment over the entire temperature range. At elevated temperature, crack growth per cycle is found to increase with decreasing frequency in both laboratory air and vacuum, suggesting a contribution from environmentally assisted crack growth. Growth rates in vacuum are as much as an order of magnitude lower than those obtained in air. Further, hold times of increasing duration are found to slightly decrease and then increase the crack growth rate at elevated temperature. At elevated temperatures, crack growth behavior appears to be a complex interaction of environmental degradation at the crack tip, crack-tip blunting due to creep, and cyclic fatigue (resharpening of the crack tip). An attempt was made to correlate the observed fatigue crack growth rates with the mechanism, or mechanisms, of fracture. The crack growth characteristics were compared with those of the alpha-2 titanium aluminide, Ti-24Al-11 Nb, and a conventional high-temperature titanium alloy, Ti-1100.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Behavior of Two Titanium Alloys at Room and Elevated Temperature written by Todd P. Albertson and published by . This book was released on 1996 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Properties of High Strength Titanium Alloys at Elevated Temperatures IMI 685 written by and published by . This book was released on 1986 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Crack Growth Characteristics of Thin Sheet Titanium Alloy Ti 6 2 2 2 2 written by and published by . This book was released on 2001 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Mechanics written by Ravinder Chona and published by ASTM International. This book was released on 1993 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the 23rd National Symposium on Fracture Mechanics, held in College Station, Texas, June 1991, present a broad overview of the current state of the art in fracture mechanics research. Following the Swerdlow Lecture (Structural Problems in Search of Fracture Mechanics Solutions by

Download or read book Fatigue and Fracture of Ordered Intermetallic Materials I written by W. O. Soboyejo and published by . This book was released on 1994 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crack Growth Rate Modeling of a Titanium aluminide Alloy Under Thermal mechanical Cycling written by John J. Pernot and published by . This book was released on 1991 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1988-04 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: