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 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 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 Elevated Temperature Effects on Fatigue and Fracture written by Robert S. Piascik and published by ASTM International. This book was released on 1997 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Influence on Fatigue Crack Propagation in Titanium Alloys at Elevated Temperature written by S. Lesterlin and published by . This book was released on 1997 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack propagation behavior of a Ti-6Al-4V alloy has been investigated at room temperature and at 300°C. Tests were run in air, high vacuum, and some other environments with controlled partial pressure of water vapor and oxygen. The enhancement of the fatigue crack growth rates observed in air in comparison to high vacuum, considered as an inert environment, is clearly attributed to the presence of water vapor. Tests in a controlled environment demonstrate that very low partial pressure can accelerate crack propagation. On the basis of previous studies on Al alloys and steels, two controlling mechanisms are considered and discussed, namely, a propagation-assisted water vapor adsorption and a hydrogen-assisted propagation.
Download or read book Fatigue Crack Growth Characteristics of Thin Sheet Titanium Alloy Ti 6 2 2 2 2 written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-23 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth rates of Ti 6-2-2-2-2 as a function of stress ratio, temperature (24 or 177 C), tensile orientation and environment (laboratory air or ultrahigh vacuum) are presented. Fatigue crack growth rates of Ti 6-2-2-2-2 are also compared with two more widely used titanium alloys (Timetal 21S and Ti 6Al-4V). The fatigue crack growth rate (da/dN) of Ti 6-2-2-2-2 in laboratory air is dependent upon stress ratio (R), particularly in the near-threshold and lower-Paris regimes. For low R (less than approximately 0.5), da/dN is influenced by crack closure behavior. At higher R (> 0.5), a maximum stress-intensity factor (K(sub max)) dependence is observed. Fatigue crack growth behavior is affected by test temperature between 24 and 177 C. For moderate to high applied cyclic-stress-intensity factors (delta-K), the slope of the log da/dN versus log delta-K curve is lower in 177 C laboratory air than 24 C laboratory air. The difference in slope results in lower values of da/dN for exposure to 177 C laboratory air compared to room temperature laboratory air. The onset of this temperature effect is dependent upon the applied R. This temperature effect has not been observed in ultrahigh vacuum. Specimen orientation has been shown to affect the slope of the log da/dN versus log delta-K curve in the Paris regime.Smith, Stephen W. and Piascik, Robert S.Langley Research CenterCRACK PROPAGATION; FATIGUE (MATERIALS); TITANIUM ALLOYS; CORROSION; STRESS RATIO; TEMPERATURE EFFECTS; CRACK CLOSURE; STRESS INTENSITY FACTORS
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 Fatigue crack Propagation in Several Titanium and Stainless steel Alloys and One Superalloy written by C. M. Hudson and published by . This book was released on 1964 with total page 40 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 A Review and Analysis of Fatigue Crack Propagation in Titanium Alloys at Room Temperature written by R.J.H. Wanhill and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Fatigue Crack Closure Measurement and Analysis written by R. Craig McClung and published by ASTM International. This book was released on 1999 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toughness and Fracture Behavior of Titanium written by R. G. Broadwell and published by ASTM International. This book was released on 1978 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of O2 H2o and N2 on the Fatigue Crack Growth Behavior of an Alpha Beta Titanium Alloy at 24 C and 177 C written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: To study the effects of atmospheric species on the fatigue crack growth behavior of an a+B titanium alloy (Ti 6-2-2-2-2) at room temperature and 177 C, fatigue tests were performed in laboratory air, ultrahigh vacuum, and high purity water vapor, oxygen, nitrogen and helium at various partial pressures. Accelerated fatigue crack growth rates in laboratory air compared to ultrahigh vacuum are linked to the damaging effects of both water vapor and oxygen. Observations of the fatigue crack growth behavior in ultrahigh purity environments, along with surface film analysis using X-ray photoelectron spectroscopy (XPS), suggest that multiple crack-tip processes govern the damaging effects of air. Three possible mechanisms are proposed: 1) at low pressure (less than 10(exp -1) Pa), accelerated da/dN is likely due to monolayer adsorption on crack-tip surfaces presumably resulting in decreased bond strengths at the fatigue crack tip, 2) for pressures greater than 10(exp -1) Pa, accelerated da/dN in oxygen may result from oxidation at the crack tip limiting reversible slip, and 3) in water vapor, absorption of atomic hydrogen at the reactive crack tip resulting in process zone embrittlement.Smith, Stephen W. and Piascik, Robert S.Langley Research CenterFATIGUE TESTS; FATIGUE (MATERIALS); CRACK PROPAGATION; TITANIUM ALLOYS; EMBRITTLEMENT; ATMOSPHERIC COMPOSITION; X RAY SPECTROSCOPY; WATER VAPOR; ULTRAHIGH VACUUM; PHOTOELECTRON SPECTROSCOPY
Download or read book Fatigue Crack Growth and Surface Reactions for Titanium Alloys Exposed to Water Vapor written by S. J. Gao and published by . This book was released on 1983 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parallel fracture mechanics and surface chemistry studies have been carried out to develop understanding of environmentally assisted fatigue crack growth in titanium alloys. Room temperature crack growth response in water vapor was determined for annealed Ti-5A1-2.5Sn alloy and for Ti-6A1-4V alloy in the solution treated and solution treated plus over-aged conditions as a function of water vapor pressure from 0.266 to 665 Pa at a frequency of 5 Hz and a load ratio of 0.1. Reference data were obtained in vacuum. The kinetics of reactions of water vapor and oxygen with fresh surfaces of Ti-5A1-2.5Sn alloy were measured at room temperature. The results showed that the reactions with water vapor and with oxygen are both rapid; with an initial sticking coefficient of 1.0 for water vapor and of 0.54 to 0.84 for oxygen. The reaction with water vapor produced a monolayer of oxide (TiO), whereas 2 to 3 layers of TiO resulted from the reaction with oxygen.
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 Elevated temperature Fatigue Properties of Two Titanium Alloys written by and published by . This book was released on 1956 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted to evaluate the unnotched fatigue properties of 3Mn Complex and 3Al-5Cr titanium alloys at elevated temperatures. Fatigue studies were conducted for each alloy at room temperature, 200, 400, 600, 800, and 1,000 degrees F. The results are presented in tabular form and as curves of stress versus cycles to failure for each test temperature. The endurance strength at 10,000,000 cycles for the 3Mn Complex alloy decreased from 79,000 psi at room temperature to 26,500 psi at 1,000 degrees F. The endurance strength at 10,000,000 cycles for the 3Al-5Cr alloy decreased from 91,000 psi at room temperature to 46,500 psi at 1,000 degrees F. The decrease in endurance strength with an increase in temperature is shown by a curve of endurance strength versus temperature for each alloy.
Download or read book Thermal Mechanical Fatigue Crack Growth in Titanium Alloys written by J. Dai and published by . This book was released on 1996 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Strain controlled thermal-mechanical fatigue crack growth (TMFCG) tests were conducted on two titanium alloys, namely Ti-6A1-4V and Ti-6Al-2Sn-4Zr-6Mo, to evaluate the effect of phase angle between strain and temperature on the TMFCG rates. Three fracture mechanics parameters were used to correlate the data: the ?K, ?Ke and ?Keff. A fractographic study of the specimens tested under TMF was carried-out to identify the mechanisms responsible for cracking in these two titanium alloys. Hence, specimens tested under in-phase (?max at Tmax), out-of-phase (?min at Tmax) and counter-clockwise diamond (90° out-of-phase) conditions were compared to specimens tested under isothermal conditions (Tmin and Tmax) for different ?Keff levels. The dominant TMF cracking mechanisms were mechanical fatigue (crack tip plasticity) and oxygen-induced embrittlement. The ?Keff was found to be the only parameter to properly correlate all the data obtained under various testing conditions. A model is developed to predict the TMFCG rates based solely on isothermal data. The model uses a linear summation of the contributions to crack growth of the two dominant mechanisms which are active at the minimum and maximum temperature of the cycle. A discussion on the applicability of the model to predict the fatigue lives of actual components is discussed.
