Effect of Heat Treatment and Cryotreatment on the Fatigue Crack Growth in Aluminium 7075 Alloy

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
P.C. Arunakumara ◽  
D. Venkatesh ◽  
K.R. Phaneesh
Keyword(s):  
Heat Treatment ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Structural Changes ◽  
Cryogenic Treatment ◽  
Vital Role ◽  
Fatigue Load ◽  
Al 7075 ◽  
7075 Alloy

Al 7075 is an aluminium alloy with zinc as major element. Al 7075 is commonly used in aircraft components, especially for critical parts like wing and fuselage components. In present investigation Al 7075 has been selected subjected to annealing, cryogenic treatment and the combination of annealing and cryogenic treatment for the study of fatigue crack growth subjected to fatigue load at constant amplitude. Specimens were subjected to fatigue crack growth as per ASTM E-647 standards and the results of fatigue crack growth were compared. NASGRO software was used to predict the fatigue crack growth (FCG) and the results are validated using experimental results. Microstructure analysis of metallic specimens was also carried out to study the micro structural changes in specimens undergoing heat treatment and cryotreatment. From the present investigation it has been observed that cryogenic treatment and heat treatments plays vital role in improving fatigue life of Al 7075 components.

scholarly journals Probabilistic Evaluation of Fatigue Crack Growth Rate for Longitudinal Tungsten Inert Gas Welded Al 6013-T4 Under Various PostWeld Heat Treatment Conditions

2019 ◽  
Vol 130 ◽  
pp. 01016 ◽  
Author(s):  
I Made Wicaksana Ekaputra ◽  
Gunawan Dwi Haryadi ◽  
Stefan Mardikus ◽  
Rando Tungga Dewa
Keyword(s):  
Heat Treatment ◽  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Postweld Heat Treatment ◽  
Inert Gas ◽  
Probabilistic Assessment

In this study, a Monte Carlo method (MCM) was applied on the fatigue crack growth rate (FCGR) curves to evaluate a probabilistic assessment for the welded longitudinal Al 6013-T4 aluminum alloy under various post-weld heat treatment (PWHT) conditions. The welded CT specimens were manufactured by a tungsten inert gas (TIG) welding, and the fatigue crack growth (FCG) tests were conducted by following ASTM E647. Before conducting the FCG test, the PWHT conditions were applied to the welded CT specimens under three different aging times of 6 h, 18 h, and 24 h at 175 C. The FCGR curves were generated from the FCG data and plotted on the da/dN versus Δk curves. The constants C and m were determined by drawing the fitting line on the FCGR curves. A sizeable random number was generated from the obtained constants by MCM. By plotting these constants, the probabilistic assessment of FCGR was determined on the da/dN versus Δk curves. The results showed that the confidence interval was appeared on the FCGR curves and limited by the upper and lower probabilistic lines. It was found that the lower and upper probabilistic lines were formed at 1 % and 90 %, respectively.

Short fatigue crack growth in AL 2024-T3 and AL 7075-T6

1992 ◽  
Vol 43 (5) ◽  
pp. 769-778 ◽  
Author(s):  
Cevdet Kaynak ◽  
Alpay Ankara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Short Fatigue Crack ◽  
Al 7075 ◽  
Al 2024

scholarly journals Probabilistic fatigue crack growth assessment of Al 7075-T6 aerospace component

2017 ◽  
Vol 5 ◽  
pp. 430-437 ◽  
Author(s):  
Ahmed Bahloul ◽  
Amal Ben Ahmed ◽  
Chokri Bouraoui
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Al 7075 ◽  
Growth Assessment

Fatigue Crack Growth Prediction under Spectrum Load in an Aluminium Alloy using Crack Driving Force K*eff Approach

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
B. Shailesh Kamath ◽  
A.R. Anilchandra ◽  
T. Sivaranjani ◽  
K. Badari Narayana ◽  
C.M. Manjunath
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Aluminium Alloy ◽  
Crack Growth ◽  
Driving Force ◽  
Fatigue Load ◽  
Single Edge ◽  
Crack Driving Force ◽  
Load Sequence ◽  
Better Than

Fatigue Crack Growth (FCG) behaviour in a Single-Edge-Notched Tension (SENT) specimen of 2024-T3 aluminium alloy under a standard mini-FALSTAFF spectrum load sequence was experimentally determined. Further, the FCG behaviour was predicted using cycle-by-cycle method and compared with experimental results. Prediction procedure involved are rain-flow counting of fatigue load cycles, estimation of crack driving force for each of the counted cycle and prediction of crack extension per cycle from constant amplitude crack growth rate equation. In the present work, a new crack driving force (CDF) K*eff involving Kujawski’s crack driving force K* in conjunction with Elber’s crack closure concept was used to account for load interaction effects. FCG prediction was also made using conventional CDF ΔKeff (Elber’s) approach. A good correlation was observed between experimental and predicted FCG behaviour under spectrum loads by the proposed K*eff approach. Also, this prediction was observed to be better than that predicted by conventional ΔKeff approach.

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