Fatigue Crack Growth Rate Characteristics of Laser Shock Peened Ti-6Al-4V

1999 ◽  
Vol 121 (3) ◽  
pp. 321-329 ◽  
Author(s):  
John J. Ruschau ◽  
Reji John ◽  
Steven R. Thompson ◽  
Theodore Nicholas
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Crack Opening ◽  
Laser Shock ◽  
Effective Stress Intensity Range ◽  
Stress Ratios

The fatigue crack growth rate (FCGR) characteristics of Laser Shock Peened (LSP) titanium 6Al-4V were examined and compared to those of unprocessed material. The FCGR resistance of LSP processed material tested at low stress ratios (R) is shown to be significantly greater than for unprocessed, baseline material. The increased damage tolerance can be attributed to the large residual compressive stresses generated by the LSP process. Differences in the growth rate behavior due to LSP can be accounted for by using the closure corrected effective stress intensity range, ΔKeff, which takes into account only the portion of loading above the crack opening load. The rationale of using ΔKeff is also demonstrated through fractographic investigations.

Effect of Environment on Fatigue Crack Propagation Behavior of an Al-Cu-Mg Aluminum Alloy

2014 ◽  
Vol 1004-1005 ◽  
pp. 142-147
Author(s):  
Ming Liu ◽  
Kun Zhang ◽  
Sheng Long Dai ◽  
Guo Ai Li ◽  
Min Hao ◽  
...  
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Fatigue Crack Propagation ◽  
Fatigue Crack Growth Rate ◽  
Fatigue Crack Propagation Behavior ◽  
Stress Ratios

The fatigue crack propagation behaviors of an Al-Cu-Mg alloy are investigated in different environments and with varying stress ratios. Fatigue experiments are carried out via a fatigue crack growth rate test in laboratory air, a 3.5% (mass fraction) NaCl solution and a tank seeper. The results show that a corrosion environment has an obvious influence on the fatigue crack growth rate, and the degrees of influence of the two different corrosive environments are basically identical. When the stress ratio is R = 0.5 and 0.06 with a decrease of the stress intensity factor, the difference in the crack propagation rates for the corrosion and air environments gradually increases. However, the corrosion acceleration in each stage of crack propagation is obvious while R=−1.

Investigation of the fatigue crack growth rate in heatresistant nickel alloys

2021 ◽  
pp. 48-63
Author(s):  
I. A. Khodinev ◽  
S. A. Monin ◽  
P. V. Ryzhkov
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Elevated Temperatures ◽  
Crack Opening ◽  
Cyclic Crack Resistance ◽  
Inconel 625

The results of tests on the FCGR (fatigue crack growth rate) of compact specimens of eccentric tension using a crack opening (COD) sensor under conditions of an asymmetric loading cycle R=0.1 at room and elevated temperatures are presented. The relationship between the conditions of force loading of preliminary growth of the initial fatigue crack is considered. The values of the effective stress intensity factor Keff were obtained, which is an important estimate for interpreting the observed character of crack growth. A comparison of the properties of the cyclic crack resistance of the VZh175-ID alloy with the properties of foreign analogues Rene 88DT, Inconel 625 SLM and domestic ones - EP741NP, EK151-ID is presented. The influence of the test temperature on the growth rate is shown. The hypothesis about the linear dependence of the parameters of the Paris equation is tested.

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