Kinetics of crack growth in maraging and medium-alloy steels during low-cycle impact fatigue tests

1977 ◽  
Vol 19 (7) ◽  
pp. 512-517 ◽  
Author(s):  
I. V. Pestov ◽  
V. A. Ostapenko ◽  
M. D. Perkas ◽  
A. Ya. Maloletnev ◽  
N. A. Kretov
Keyword(s):  
Crack Growth ◽  
Fatigue Tests ◽  
Impact Fatigue ◽  
Alloy Steels ◽  
Kinetics Of

Setup for studying the kinetics of crack growth in cyclic bending tests

2020 ◽  
Vol 86 (7) ◽  
pp. 59-64
Author(s):  
V. N. Pustovoit ◽  
S. A. Grishin ◽  
V. V. Duka ◽  
V. V. Fedosov
Keyword(s):  
Experimental Data ◽  
Fatigue Crack ◽  
Crack Growth ◽  
Fatigue Cracks ◽  
Fatigue Tests ◽  
Computer Processing ◽  
Crack Development ◽  
Potential Difference ◽  
Fatigue Crack Development ◽  
Kinetics Of

The goal of the study is analysis of the features of fatigue cyclic fracture of steels. An installation has been designed to induce fatigue cracks and to study the kinetics of fatigue crack development. Crack growth is recorded by the method of potential difference. The data on the crack growth kinetics were processed on a computer using LGraph2 programs and Excel spreadsheets. When studying the kinetics of the fatigue crack development, the electrodes were soldered to the edges of the initial notch of the sample and time dependence of the potential difference was recorded on a computer during crack growth. To interpret the experimental data, a calibration chart in the coordinates «potential difference (U) – the crack length (Lcr)» constructed on the basis of the millivoltmeter readings was used, with due regard for the size of the sample section, current flow and length of the fatigue crack. Cyclic loading of the sample resulted in a stepwise character of the crack growth: first occurred zone of plastic deformation of the metal is then followed by accumulation of stresses of a certain size, their relaxation in the form of a crack and sudden crack growth. An abrupt crack growth is clearly visible on a graph of the fatigue crack growth rate obtained upon computer processing of experimental data. Using a graphical editor KOMPAS, a graph was constructed which characterized the growth of the fatigue crack against the number of cycles of fatigue tests for bending. The experimental setup provides the possibility of fatigue crack formation for impact tests, determination of the work of crack propagation, as well as studying of the kinetics of crack development and computer processing of experimental data.

Fracture Behavior of Ceramics Used in Multilayer Capacitors

1986 ◽  
Vol 72 ◽  
Author(s):  
Theresa L. Baker ◽  
Stephen W. Freiman
Keyword(s):  
Crack Growth ◽  
Fracture Behavior ◽  
Ceramic Materials ◽  
Fatigue Tests ◽  
Internal Stresses ◽  
Crack Growth Behavior ◽  
Multilayer Capacitors ◽  
Materials Used ◽  
Aging Phenomena

AbstractThis study involved the determination of the effects of composition and microstructure on the fracture toughness and susceptibility to environmentally enhanced crack growth of several ceramic materials used in multilayer capacitors. Indentation-fracture procedures were used to measure KIC as well as to assess the possible effects of internal stresses on the fracture behavior of these materials and to correlate dielectric aging phenomena with strength. The environmentally enhanced crack growth behavior of these materials was determined by conducting dynamic fatigue tests in water.

Effect of Processing Layer on Fatigue Strength of Extruded AZ61 Magnesium Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 429-432 ◽  
Author(s):  
Yukio Miyashita ◽  
Kyohei Kushihata ◽  
Toshifumi Kakiuchi ◽  
Mitsuhiro Kiyohara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Crack Growth Resistance ◽  
Az61 Magnesium Alloy

Fatigue Property of an Extruded AZ61 Magnesium Alloy with the Processing Layer Introduced by Machining was Investigated. Rotating Bending Fatigue Tests were Carried out with the Specimen with and without the Processing Layer. According to Results of the Fatigue Tests, Fatigue Life Significantly Increased by Introducing the Processing Layer to the Specimen Surface. Fatigue Crack Initiation and Propagation Behaviors were Observed by Replication Technique during the Fatigue Test. Fatigue Crack Initiation Life of the Specimen with the Processing Layer was Slightly Longer than that of the Specimen without the Processing Layer. Higher Fatigue Crack Growth Resistance was also Observed when the Fatigue Crack was Growing in the Processing Layer in the Specimen with the Processing Layer. the Longer Fatigue Life Observed in the Fatigue Test in the Specimen with the Processing Layer could be Mainly due to the Higher Crack Growth Resistance. it is Speculated that the Fatigue Strength can be Controlled by Change in Condition of Machining Process. it could be Effective way in Industry to Improved Fatigue Strength only by the Cutting Process without Additional Surface Treatment Process.

Fatigue/Creep Interactions in Ni3Al-Base Alloys

1988 ◽  
Vol 133 ◽  
Author(s):  
G. M. Camus ◽  
D. J. Duquette ◽  
N. S. Stoloff
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Frequency Effect ◽  
Propagation Mode ◽  
Crack Blunting ◽  
Fatigue Crack Growth Test

ABSTRACTStress-controlled fatigue tests and fatigue crack growth rate tests respectively have been carried out on two Ni3Al Cr/Zr alloys, IC 218 at 600°C and 800°C, and IC 221 at 800°C, in vacuum, at various test frequencies. Decreasing the test frequency and/or increasing the temperature leads to a decrease in the number of cycles to failure, and a gradual disappearance of a fatigue fracture zone. In fatigue crack propagation tests, the crack growth rate only decreases at the lowest frequency and remains constant in the major part of the frequency range investigated. The fatigue propagation mode in all cases is intergranular. These trends are shown in both cases to be related to a true creep component but, under fatigue crack growth test conditions, crack blunting intervenes gradually as the frequency is decreased, leading therefore to a less severe frequency effect.

Kinetics of environmental fatigue crack growth in a nickel-copper alloy: Part II. In hydrogen

1978 ◽  
Vol 9 (8) ◽  
pp. 1107-1111 ◽  
Author(s):  
R. J. Richards ◽  
S. Purushothaman ◽  
J. K. Tien ◽  
J. D. Frandsen ◽  
O. Buck
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Copper Alloy ◽  
Nickel Copper ◽  
Alloy Part ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document