scholarly journals Fish-eye fracture in high-cycle fatigue at elevated temperatures.

1988 ◽  
Vol 37 (423) ◽  
pp. 1423-1428
Author(s):  
Kenji KANAZAWA ◽  
Morio SATO ◽  
Megumi KIMURA ◽  
Satoshi NISHIJIMA
Keyword(s):  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Cycle Fatigue ◽  
Fish Eye

scholarly journals Fish-Eye Fracture of a Low Alloy Steel under High Cycle Fatigue at Elevated Temperatures

2007 ◽  
Vol 56 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Kenji KANAZAWA ◽  
Isao SUMIYOSHI ◽  
Kazuhiro SHIRAKI ◽  
Maya SUGIMOTO
Keyword(s):  
Alloy Steel ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Cycle Fatigue ◽  
Low Alloy Steel ◽  
Fish Eye

High Cycle Fatigue Properties of Multi-Directionally Forged Commercial Purity Grade 2 Ti Plate

2018 ◽  
Vol 916 ◽  
pp. 166-169
Author(s):  
Ilhamdi ◽  
Toshifumi Kakiuchi ◽  
Hiromi Miura ◽  
Yoshihiko Uematsu
Keyword(s):  
Crack Initiation ◽  
High Cycle Fatigue ◽  
Pure Titanium ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Commercially Pure Titanium ◽  
Cycle Fatigue ◽  
Subsurface Crack ◽  
Initiation Mechanism ◽  
Fish Eye

Tension-tension fatigue tests were conducted using ultrafine-grained commercially pure Titanium (Ti) plates fabricated by multi-directional forging (MDFing). The MDFed pure Ti plates with the thickness of 1 mm were developed aiming at dental implant application. The fatigue properties of MDFed pure Ti plates were superior to those of the conventional rolled pure Ti plates. The higher fatigue strengths in MDFed plates could be attributed to the much finer grains evolved by MDFing. Fatigue crack initiated from specimen surface, when number of cycles to failure was shorter than 106 cycles. In the high cycle fatigue (HCF) region, however, subsurface crack initiation with typical fish-eye feature was recognized in the MDFed pure Ti plate in spite of the thin thickness. Fractographic analyses revealed that no inclusion existed at the center of fish-eye. The subsurface crack initiation mechanism could be related to the inhomogeneity of microstructure with some coarse grains in the inner part of the plate.

A Methodology for High Cycle Fatigue Characterization of Lead-Free Interconnects Under Simultaneous Harsh Environments of High Temperature and Vibration

2013 ◽  
Author(s):  
Pradeep Lall ◽  
Geeta Limaye
Keyword(s):  
High Temperature ◽  
High Speed ◽  
High Cycle Fatigue ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
Natural Frequencies ◽  
Image Correlation ◽  
Lead Free ◽  
Cycle Fatigue ◽  
Increase With Increase

Current trends in the automotive industry warrant a variety of electronics for improved control, safety, efficiency and entertainment. Many of these electronic systems like engine control units, variable valve sensor, crankshaft-camshaft sensors are located under-hood. Electronics installed in under-hood applications are subjected simultaneously to mechanical vibrations and thermal loads. Typical failure modes caused by vibration induced high cycle fatigue include solder fatigue, copper trace or lead fracture. The solder interconnects accrue damage much faster when vibrated at elevated temperatures. Industry migration to lead-free solders has resulted in a proliferation of a wide variety of solder alloy compositions. Presently, the literature on mechanical behavior of lead-free alloys under simultaneous harsh environment of high-temperature vibration is sparse. In this paper, the reduction in stiffness of the PCB with temperature has been demonstrated by measuring the shift in natural frequencies. The test vehicle consisting of a variety of lead-free SAC305 daisy chain components including BGA, QFP, SOP and TSOPs has been tested to failure by subjecting it to two elevated temperatures and harmonic vibrations at the corresponding first natural frequency. The test matrix includes three test temperatures of 25C, 75C and 125C and simple harmonic vibration amplitude of 10G which are values typical in automotive testing. PCB deflection has been shown to increase with increase in temperature. The full field strain has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. Material properties of the PCB at test temperatures have been measured using tensile tests and dynamic mechanical analysis. FE simulation using global-local finite element models is thus correlated with the system characteristics such as modal shapes, natural frequencies and displacement amplitudes for every temperature. The solder level stresses have been extracted from the sub-models. Stress amplitude versus cycles to failure curves are obtained at all the three test temperatures. A comparison of failure modes for different surface mount packages at elevated test temperatures and vibration has been presented in this study.

OS1514 High-Cycle Fatigue Strength of Modified 9Cr-1Mo Steel at Elevated Temperatures

2013 ◽  
Vol 2013 (0) ◽  
pp. _OS1514-1_-_OS1514-3_
Author(s):  
Motoyuki OCHI ◽  
Ken SUZUKI ◽  
Isamu NONAKA ◽  
Hideo MIURA
Keyword(s):  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Cycle Fatigue

Micromechanics of an Extrusion in High-Cycle Fatigue With Creep

1990 ◽  
Vol 57 (4) ◽  
pp. 815-820 ◽  
Author(s):  
T. H. Lin ◽  
S. R. Lin ◽  
X. Q. Wu
Keyword(s):  
Crack Initiation ◽  
Tensile Strain ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Tensor Component ◽  
Shear Stresses ◽  
Cycle Fatigue ◽  
Thin Slice

Extrusions and intrusions often are sites of fatigue cracks. The extent of extrusions is important in fatigue crack initiation. Metals often are subject to fatigue loadings at elevated temperatures. At temperatures below one half of the melting temperature slip is the main mechanism of inelastic deformation. In this study, an aluminum polycrystal loaded in this temperature range is considered. A most favorably oriented crystal located at a free surface of a f.c.c. polycrystal subject to creep under cyclic tension and compression of high-cycle fatigue is considered. An extrusion in this crystal is shown to be produced by a positive slip in one thin slice “P” and a negative slip in a closely located slice “Q”. An initial tensile strain εααI in the thin slice “R” sandwiched between P and Q causes a positive initial shear stress ταβI in P and a negative one in Q. It is shown that the extrusion growth causes a tensile strain in R, which can activate a second slip system giving a creep strain with a tensor component εαα. It has the same effect as the initial strain εααI in causing this difference in shear stresses in P and Q and gives much additional extrusion growth. The extent of intrusion and extrusion is important in this study of crack initiation.

High cycle fatigue behavior of a single crystal superalloy at elevated temperatures

2007 ◽  
Vol 454-455 ◽  
pp. 357-366 ◽  
Author(s):  
Y. Liu ◽  
J.J. Yu ◽  
Y. Xu ◽  
X.F. Sun ◽  
H.R. Guan ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Cycle Fatigue ◽  
Elevated Temperatures ◽  
Fatigue Behavior ◽  
Single Crystal Superalloy ◽  
Cycle Fatigue
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