Kinetics and Mechanisms of Degradation of the Surface Layers of Gas-Turbine Engine Structural Components Under Cyclic Thermal Loading During Initiation and Propagation of Thermal Fatigue Cracks

2016 ◽  
Vol 48 (6) ◽  
pp. 784-790 ◽  
Author(s):  
K. P. Buiskikh ◽  
S. G. Kiselevskaya ◽  
L. V. Kravchuk ◽  
E. A. Zadvornyi ◽  
N. N. Feofentov
Keyword(s):  
Gas Turbine ◽  
Thermal Fatigue ◽  
Thermal Loading ◽  
Fatigue Cracks ◽  
Structural Components ◽  
Surface Layers ◽  
Turbine Engine ◽  
Cyclic Thermal Loading ◽  
Initiation And Propagation ◽  
Thermal Fatigue Cracks

The effect of the tensile load on the initiation of thermal fatigue cracks in gas turbine blades

1969 ◽  
Vol 1 (4) ◽  
pp. 327-331
Author(s):  
A. P. Voloshchenko ◽  
L. B. Getsov ◽  
L. V. Kravchuk ◽  
R. I. Kuriat ◽  
G. N. Tret'yachenko
Keyword(s):  
Gas Turbine ◽  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
Turbine Blades ◽  
Tensile Load ◽  
Gas Turbine Blades ◽  
Thermal Fatigue Cracks

Thermal Fatigue Cracks in Gas Turbine Heat Shield Plates

2012 ◽  
Vol 49 (2) ◽  
pp. 99-108
Author(s):  
A. Neidexl ◽  
S. Riesenbeck
Keyword(s):  
Gas Turbine ◽  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
Heat Shield ◽  
Thermal Fatigue Cracks

Assessment of thermal behavior of a cooling system to reduce thermal fatigue cracks in aluminum injection molds

2020 ◽  
pp. 75-86
Author(s):  
Sergio Antonio Camargo ◽  
Lauro Correa Romeiro ◽  
Carlos Alberto Mendes Moraes
Keyword(s):  
Thermal Fatigue ◽  
Cooling System ◽  
Fatigue Cracks ◽  
Cooling Water ◽  
Thermal Conditions ◽  
Thermal Gradients ◽  
Ansys Software ◽  
Cooling Systems ◽  
Thermal Fatigue Cracks ◽  
Number Of Cycles

The present article aimed to test changes in cooling water temperatures of males, present in aluminum injection molds, to reduce failures due to thermal fatigue. In order to carry out this work, cooling systems were studied, including their geometries, thermal gradients and the expected theoretical durability in relation to fatigue failure. The cooling system tests were developed with the aid of simulations in the ANSYS software and with fatigue calculations, using the method of Goodman. The study of the cooling system included its geometries, flow and temperature of this fluid. The results pointed to a significant increase in fatigue life of the mold component for the thermal conditions that were proposed, with a significant increase in the number of cycles, to happen failures due to thermal fatigue.

Heat Resistance of Ferritic Stainless Steels with 15% Chromium for Automobile Exhaust System

2011 ◽  
Vol 239-242 ◽  
pp. 1799-1803
Author(s):  
Hua Bing Li ◽  
Zhou Hua Jiang ◽  
Qi Feng Ma ◽  
Dong Ping Zhan
Keyword(s):  
High Temperature ◽  
Grain Boundaries ◽  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
Exhaust System ◽  
High Temperature Strength ◽  
Temperature Oxidation ◽  
Ferritic Stainless Steels ◽  
Automobile Exhaust ◽  
Thermal Fatigue Cracks

The high-temperature strength and thermal fatigue properties of Fe-Cr-Nb-Mo ferritic stainless steel (FSSNEW) developed for automobile exhaust system were investigated. The results show that the high-temperature tensile strength and yield strength of FSSNEW are better than or equal to those of the presently applied ferritic stainless steels. The thermal fatigue cracks nucleate at the V-notch. The inclusions along grain boundaries become prior regions for initiation of the cracks. The inclusions distributed at the defects make the formation of cracks in the materials easily through the effects of cycle thermal stress and thermal strain. The length and propagated rate of thermal fatigue cracks increase with the maximum tested temperature increasing. When the maximum temperature arrives at 900°C, the high-temperature oxidation is serious along the grain boundaries, which aggravates the cracks propagating along the grain boundaries. The principle mechanism of stress assisted grain boundary oxygen (SAGBO) embrittlement can be applied to illustrate the effects of external stress on aggravating the damage caused by environmental factors. Therefore, the high-temperature oxidation is the main reason for the propagation of thermal fatigue cracks. The FSSNEW is satisfied for the applied requirement of high-temperature strength in the hot side of the automobile exhaust system.

Estimation of Damage to the Collector of a Water Economizer by Thermal Fatigue Cracks

2004 ◽  
Vol 40 (1) ◽  
pp. 132-138 ◽  
Author(s):  
R. Ya. Kosarevych ◽  
O. Z. Student ◽  
Ya. D. Onyshchak ◽  
A. D. Markov ◽  
I. V. Ripei ◽  
...  
Keyword(s):  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
Thermal Fatigue Cracks ◽  
Water Economizer

In-Situ Monitoring via Synchrotron Radiation Laminography of Thermal Fatigue Cracks at Die-Attached Joints Under Cyclic Energization Loading

2017 ◽  
Author(s):  
Hiroyuki Tsuritani ◽  
Toshihiko Sayama ◽  
Yoshiyuki Okamoto ◽  
Takeshi Takayanagi ◽  
Masato Hoshino ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Thermal Fatigue ◽  
Fatigue Cracks ◽  
In Situ Monitoring ◽  
X Ray ◽  
Crack Propagation Process ◽  
Thermal Fatigue Cracks

Recently, due to the increasing heat density of printed circuit boards (PCBs), thermal fatigue damage in the joints has exerted a more significant influence on the reliability of electronic components. Accordingly, the development of a new nondestructive inspection technology is strongly desired by related industries. The authors have applied a synchrotron radiation X-ray micro-tomography system to the nondestructive observation of micro-cracks. However, the reconstruction of CT images is difficult for planar objects such as PCB substrates, due to insufficient X-ray transmission in the direction parallel to the substrates. In order to solve this problem, a synchrotron radiation laminography system was developed to relax size restrictions on the observation samples, and was applied to the three-dimensional nondestructive evaluation of several kinds of solder joints, which were loaded under accelerated thermal cyclic conditions via thermal shock tests. Moreover, the thermal fatigue crack propagation process that occurs under actual PCB energization loading conditions will differ from that under the usual acceleration test conditions. In this work, the possibility of in-situ monitoring of the thermal fatigue crack propagation process using the laminography system was investigated at die-attached joints subjected to cyclic energization loading, which is close to the actual usage conditions of PCBs. The optical system developed for use in the laminography system was constructed to provide a rotation stage with a tilt from the horizontally incident X-ray beam, and to obtain X-ray projection images via a beam monitor. In this manner, the X-ray beam is sufficiently transmitted through the planar specimen in all projections. The observed specimens included several die-attached joints, in which 3 mm square ceramic dies had been mounted on a 40 mm square FR-4 substrate using Sn-3.0wt%Ag-0.5wt%Cu solder. Consequently, the laminography system was successfully applied to the in-situ monitoring of thermal fatigue cracks that appeared in the solder layer under cyclic energization. This was possible because the laminography images obtained in the energization state have a quality that is equivalent to those obtained in a non-energized state, provided that the temperature distribution of the specimen is stable. In addition, the fatigue crack propagation process can be quantitatively evaluated by measuring the crack surface area and calculating the average crack propagation rate. However, in some cases, the appearance of thermal fatigue cracks was not observed in a solder layer that had been loaded by the accelerated thermal cycle test. This result strongly suggests that delamination occurred at the interface, which indicates that the corresponding fracture mode was significantly influenced by the type of thermal loading.

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