Compressive Fatigue of a Plasma Sprayed Zr02-8 wt%Y203 and Zr02-10wt%NiCrAlCoY TTBC

1995 ◽  
Vol 117 (3) ◽  
pp. 305-310 ◽  
Author(s):  
B. P. Johnsen ◽  
T. A. Cruse ◽  
R. A. Miller ◽  
W. J. Brindley
Keyword(s):  
Compressive Strength ◽  
Fatigue Life ◽  
Elevated Temperatures ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Free Standing ◽  
Initial Portion ◽  
Base Materials ◽  
Plasma Sprayed ◽  
Tubular Specimens

High cycle (>106 cycles) fatigue (HCF) behavior of thick thermal barrier coatings (TTBC’s) was examined for applied stresses near the compressive strength of the material. Test data were obtained on four coating systems: two base materials in the unsealed and CrO2 dip sealed conditions. Free standing tubular specimens were evaluated. The data show that compressive fatigue limits exist for the four coating systems at room temperature (RT) and sealing with CrO2 improves RT fatigue life. Test results also show the ratio of the peak cyclic stress, at 105 cycles, to ultimate compressive strength (UCS) of the Yttria Stabilized Zirconia (YSZ) tubular specimens approaches 0.90 at R = 0.6 (R = minimum/maximum compressive stress). Residual UCS increases were observed after fatigue run-outs at elevated temperatures (5 at 700°C and 1 at 400°C) for both YSZ and the cermet. Ratchetting with cyclic hardening was observed during fatigue with deformation occurring primarily in the initial portion of the high cycle fatigue life of the specimens.

High Temperature Low Cycle Fatigue of Superalloys Inconel 713LC and Inconel 792-5A

2007 ◽  
Vol 348-349 ◽  
pp. 101-104 ◽  
Author(s):  
Martin Petrenec ◽  
Karel Obrtlík ◽  
Jaroslav Polák
Keyword(s):  
Fatigue Life ◽  
Volume Fraction ◽  
Low Cycle Fatigue ◽  
Structural Parameters ◽  
Cyclic Hardening ◽  
Cyclic Stress ◽  
Plastic Strain Amplitude ◽  
Nickel Base Superalloy ◽  
Polycrystalline Nickel ◽  
Stress Strain

Cylindrical specimens of cast polycrystalline nickel base superalloy Inconel 713 LC and Inconel 792-5A were cyclically strained under total strain control at 23 and 700 °C. Morphology and volume fraction of γ´ precipitates are different in both materials. Cyclic hardening/softening curves, cyclic stress-strain curves, and fatigue life curves were obtained at both temperatures. The cyclic hardening/softening curves depend both on temperature and plastic strain amplitude. The cyclic stressstrain curves can be fitted by power law. Experimental data of fatigue life curves can be approximated by the Manson-Coffin and Basquin laws. Dislocation structure was studied in transmission electron microscope. Planar dislocation arrangements in the form of bands parallel to {111} planes were identified in both superalloys at both temperatures. Stress-strain response and fatigue life characteristics are compared at both temperatures and discussed in relation to dislocation arrangement and structural parameters of the materials studied.

Low Cycle Fatigue Behavior of 429EM Ferritic Stainless Steel at Elevated Temperatures

2004 ◽  
Vol 261-263 ◽  
pp. 1135-1140 ◽  
Author(s):  
Keum Oh Lee ◽  
Sam Son Yoon ◽  
Soon Bok Lee ◽  
Bum Shin Kim
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Fatigue Life ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Dynamic Strain ◽  
Temperature Structure ◽  
Cycle Fatigue

In recent, ferritic stainless steels are widely used in high temperature structure because of their high resistance in thermal fatigue and low prices. Tensile and low cycle fatigue(LCF) tests on 429EM stainless steel were performed at several temperatures from room temperature to 600°C. Elastic modulus, yield stress and ultimate tensile strength(UTS) decreased with increasing temperature. Considerable cyclic hardening occurred at 200°C and 400°C. 475°C embrittlement observed could not explain this phenomenon but dynamic strain aging(DSA) observed from 200°C to 500°C could explain the hardening mechanism at 200°C and 400°C. And it was observed that plastic strain energy density(PSED) was useful to predict fatigue life when large cyclic hardening occurred. Fatigue life using PSED over elastic modulus could be well predicted within 2X scatter band at various temperatures.

High Temperature Inelastic Deformation of the B1900 + Hf Alloy Under Multiaxial Loading: Theory and Experiment

1990 ◽  
Vol 112 (1) ◽  
pp. 7-14 ◽  
Author(s):  
K. S. Chan ◽  
U. S. Lindholm ◽  
S. R. Bodner ◽  
A. Nagy
Keyword(s):  
Elevated Temperatures ◽  
Cyclic Hardening ◽  
Thin Wall ◽  
Multiaxial Loading ◽  
Biaxial Strain ◽  
Cyclic Tests ◽  
Comparable Magnitude ◽  
Tubular Specimens ◽  
Strain Cycling ◽  
Theory And Experiment

The multiaxial deformation behavior of the Ni-based alloy B1900 + Hf has been studied at elevated temperatures in the range of 649–982°C. Combined tension/ torsion cyclic tests were performed on thin-wall tubular specimens under both in-phase and out-of-phase strain-controlled loading cycles. Both straining conditions resulted in stress loci of comparable magnitude, exhibiting no difference in cyclic hardening response. A phase angle was observed between the deviatoric stress and the incremental plastic strain vectors during 90° out-of-phase strain cycling, and nonproportional stress relaxation occurred under biaxial strain hold. The overall results have been used to assess the flow law, the hardening equations, and the applicability of the J2-based, elastic-viscoplastic model of Bodner-Partom for multiaxial loading conditions. The overall agreement between theory and experiment is good and discrepancies are discussed in relation to micromechanical considerations.

Low Cycle Fatigue of Cast Superalloy Inconel 738LC at High Temperature

2008 ◽  
Vol 385-387 ◽  
pp. 581-584 ◽  
Author(s):  
Karel Obrtlík ◽  
Alice Chlupová ◽  
Martin Petrenec ◽  
Jaroslav Polák
Keyword(s):  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
High Amplitude ◽  
Cyclic Stress ◽  
Nickel Base Superalloy ◽  
Polycrystalline Nickel ◽  
Stress Strain ◽  
Increasing Temperature ◽  
Inconel 738Lc

Cylindrical specimens of cast polycrystalline nickel base superalloy Inconel 738LC were cyclically strained under total strain control at 23 and 800 °C to fracture. Cyclic hardening/softening curves, cyclic stress-strain curves, and fatigue life curves were obtained at both temperatures. Surface relief was studied in specimens fatigued to failure using scanning electron microscopy. Cyclic hardening/softening behaviour depends both on temperature and strain amplitude. Low amplitude straining was characterized by saturation of the stress amplitude. In high amplitude straining a pronounced hardening was found which was followed by saturation at room temperature and by cyclic softening at 800 °C. The cyclic stress-strain curves can be fitted by power law. They are shifted to lower stresses with increasing temperature. Fatigue life curves can be approximated by the Manson- Coffin and Basquin laws. The Manson-Coffin and Basquin curves are shifted to lower lives with increasing temperature. Slip markings were detected on specimen surface at all test temperatures. When temperature grows the density of slip markings is reduced.

Fatigue of Microlithographically-Patterned Free-Standing Aluminum Thin Film Under Axial Stresses

1995 ◽  
Vol 117 (1) ◽  
pp. 1-6 ◽  
Author(s):  
David T. Read ◽  
James W. Dally
Keyword(s):  
Thin Film ◽  
Fatigue Life ◽  
Ultimate Strength ◽  
Upper Bound ◽  
Cyclic Stress ◽  
Free Standing ◽  
Titanium Thin Film ◽  
Titanium Aluminum ◽  
Stress Cycles ◽  
Repeated Cycling

Fatigue life as a function of number of stress cycles has been determined for three-layer titanium-aluminum-titanium thin-film specimens. For nominal stresses ranging from 50 to 90 percent of the upper-bound ultimate strength, the fatigue lives ranged up to 76 cycles. In all specimens, active cracks were observed after only a few stress cycles. These cracks grew with repeated cycling. The fatigue life was reached when the specimen could no longer sustain the maximum cyclic stress.

FEDERAL BRONZE 822

Alloy Digest ◽  
1976 ◽  
Vol 25 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Copper Base ◽  
High Speeds ◽  
High Lead

Abstract FEDERAL BRONZE 822 is a copper-base, high-lead bearing bronze with superior resistance to scoring and seizure beyond the endurance and danger limits of ordinary bearing bronzes. It is used in applications involving high speeds, poor lubrication, heat-generating loads, elevated temperatures, dusty and gritty surroundings, or where a liquid other than oil is used as the lubricant. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on casting, heat treating, machining, joining, and surface treatment. Filing Code: Cu-324. Producer or source: Federal Bronze Products Inc..

CARPENTER T-K

Alloy Digest ◽  
1969 ◽  
Vol 18 (5) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Extrusion Dies ◽  
Temperature Performance ◽  
Red Hardness

Abstract Carpenter T-K is a tungsten-chromium type hot-work steel having good red-hardness and resistance to abrasion. It will withstand high operating temperatures up to 1000 F for long periods. It is recommended for hot shear blades, forging and extrusion dies, hot compression tools, and similar applications where high compressive strength and wear resistance at elevated temperatures are required. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-219. Producer or source: Carpenter.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

An Investigation of Cyclic Transient Behavior and Implications on Fatigue Life Estimates

1997 ◽  
Vol 119 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Yanyao Jiang ◽  
Peter Kurath
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Cyclic Hardening ◽  
Transient Behavior ◽  
Fatigue Tests ◽  
304 Stainless Steel ◽  
Deformation History ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Track Deformation

Current research focuses on proportional cyclic hardening and non-Massing behaviors. The interaction of these two hardenings can result in the traditionally observed overall softening, hardening or mixed behavior exhibited for fully reversed strain controlled fatigue tests. Proportional experiments were conducted with five materials, 304 stainless steel, normalized 1070 and 1045 steels, and 7075-T6 and 6061-T6 aluminum alloys. All the materials display similar trends, but the 304 stainless steel shows the most pronounced transient behavior and will be discussed in detail. Existing algorithms for this behavior are evaluated in light of the recent experiments, and refinements to the Armstrong-Frederick class of incremental plasticity models are proposed. Modifications implemented are more extensive than the traditional variation of yield stress, and a traditional strain based memory surface is utilized to track deformation history. Implications of the deformation characteristics with regard to fatigue life estimation, especially variable amplitude loading, will be examined. The high-low step loading is utilized to illustrate the effect of transient deformation on fatigue life estimation procedures, and their relationship to the observed and modeled deformation.

Effects of Elevated Temperatures on the Compressive Strength of HFCC

2011 ◽  
Vol 261-263 ◽  
pp. 416-420 ◽  
Author(s):  
Fu Ping Jia ◽  
Heng Lin Lv ◽  
Yi Bing Sun ◽  
Bu Yu Cao ◽  
Shi Ning Ding
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Relative Strength ◽  
Ordinary Concrete ◽  
Residual Compressive Strength ◽  
Fly Ash Concrete ◽  
The Relationship

This paper presents the results of elevated temperatures on the compressive of high fly ash content concrete (HFCC). The specimens were prepared with three different replacements of cement by fly ash 30%, 40% and 50% by mass and the residual compressive strength was tested after exposure to elevated temperature 250, 450, 550 and 650°C and room temperature respectively. The results showed that the compressive strength apparently decreased with the elevated temperature increased. The presence of fly ash was effective for improvement of the relative strength, which was the ratio of residual compressive strength after exposure to elevated temperature and ordinary concrete. The relative compressive strength of fly ash concrete was higher than those of ordinary concrete. Based on the experiments results, the alternating simulation formula to determine the relationship among relative strength, elevated temperature and fly ash replacement is developed by using regression of results, which provides the theoretical basis for the evaluation and repair of HFCC after elevated temperature.

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