Scanning Acoustic Microscopy and x-ray Diffraction Investigation of Near Crack Tip Stresses

1999 ◽  
Vol 591 ◽  
Author(s):  
S. Sathish ◽  
R. W. Martin
Keyword(s):  
Rayleigh Wave ◽  
Crack Tip ◽  
Acoustic Velocity ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
X Ray Diffraction ◽  
Rayleigh Wave Velocity ◽  
X Ray ◽  
Wave Velocities ◽  
Velocity Images

ABSTRACTScanning Acoustic Microscopy has been used to measure and map the Rayleigh wave velocity and the Surface Skimming Longitudinal wave velocities near a crack tip in a sample of Ti-6AI-4V. X-ray diffraction measurements have been performed to map the stress in the same region of the sample. The differences in the contrast between the two acoustic velocity images and their sensitivity to stress are examined. Similarities between x-ray stress images and acoustic velocity images are discussed.

Characterization of Stress at a Ceramic/Metal Joined Interface by the Vz Technique of Scanning Acoustic Microscopy

2002 ◽  
Vol 124 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Chiaki Miyasaka ◽  
Bernard R. Tittmann ◽  
Shun-Ichiro Tanaka
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Wave Velocity ◽  
Dissimilar Materials ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities

It is well known that the process of heating and then cooling dissimilar materials introduces considerable stress at and near the interface. In this article, first, the surface wave velocity distributions obtained with the Vz curve technique were found to compare well with residual stress distribution measured by the finely collimated X-ray diffraction technique. Second, a delamination was introduced at the interface. The Vz curve technique was then used again to measure the surface acoustic wave velocity along the interface. The defective specimens showed significantly different patterns of surface acoustic wave velocities. Thus, this study presents useful guidelines in discriminating between sound and defective ceramic/metal joints by scanning acoustic microscopy.

Synthesis of Superhard and Ultrahard Materials by 3D-polymerization of C60, C70 Fullerenes Under High Pressure (15 GPa) and Temperatures up to 1820 K

2006 ◽  
Vol 61 (12) ◽  
pp. 1547-1554 ◽  
Author(s):  
Vladimir D. Blank ◽  
Sergei G. Buga ◽  
Gennadi A. Dubitsky ◽  
Nadejda R. Serebryanaya ◽  
Vyatcheslav M. Prokhorov ◽  
...  
Keyword(s):  
High Pressure ◽  
Sound Wave ◽  
Acoustic Microscopy ◽  
X Ray Diffraction ◽  
Quenching Rate ◽  
X Ray ◽  
Wave Velocities ◽  
Microscopy Techniques ◽  
Temperature Maps ◽  
Microscopy Images

Solid fullerenes C60 and C70 have been treated at high pressure of 15 GPa and high temperatures of 520 - 1820 K for a time of exposure of 60 s and a quenching rate of 300 K s−1 using a toroid-type apparatus. X-ray diffraction and Raman spectra confirm the realization of 3D-polymerized phases in these solids at 15 GPa. The pressure/temperature maps of synthesis of metastable carbon phases on the basis of C60 and C70 have thus been extended to 15 GPa. The longitudinal and shear sound wave velocities were measured by acoustic microscopy techniques. A maximum sound wave velocity of (21±1)×105 m s−1 was observed in the sample synthesized from C60 at T = 1170 K. The elastic constants were calculated using experimental data. The acoustic microscopy images of experimental samples have been investigated.

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

scholarly journals In situ through-thickness analysis of crack tip fields with synchrotron X-ray diffraction

2019 ◽  
Vol 127 ◽  
pp. 500-508 ◽  
Author(s):  
P. Lopez-Crespo ◽  
J.V. Peralta ◽  
J.F. Kelleher ◽  
P.J. Withers
Keyword(s):  
Crack Tip ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crack Tip Fields

EFFECT OF Nb2O5 ON THE ELASTIC BEHAVIOR OF PZT FERROELECTRIC MATERIALS

2002 ◽  
Vol 16 (03) ◽  
pp. 79-85
Author(s):  
Y. PURUSHOTHAM ◽  
O. P. THAKUR ◽  
CHANDRA PRAKASH ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Elastic Moduli ◽  
Solid State Reaction Method ◽  
Ferroelectric Materials ◽  
Ferroelectric Ceramics ◽  
Elastic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission

A series of ferroelectric ceramics with the compositional formula PbZr0.52Ti0.48O3 + x wt% of Nb2O5 were prepared by the solid state reaction method. Samples were characterized by studying their X-ray diffraction and dielectric measurements. The longitudinal and shear wave velocities and corresponding elastic moduli were determined at room temperature by using the pulse transmission technique. The values of Young's modulus (E), and the rigidity (n) and bulk (k) moduli were corrected to theoretical density and were found to increase with increasing dopant concentration. The variation of elastic moduli and other elastic parameters such as Debye temperature (θ D ) with composition are explained qualitatively.

Investigation of the domain switching zone near a crack tip in pre-poled lead zirconate titanate ceramic via in situ X-ray diffraction

2011 ◽  
Vol 64 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Soodkhet Pojprapai (Imlao) ◽  
Jacob L. Jones ◽  
Tania Vodenitcharova ◽  
Joel V. Bernier ◽  
Mark Hoffman
Keyword(s):  
Lead Zirconate Titanate ◽  
Domain Switching ◽  
Crack Tip ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconate Titanate ◽  
Lead Zirconate Titanate Ceramic ◽  
Titanate Ceramic

Investigation of the Stress Fields Around a Fatigue Crack in Aluminium Alloy 5091

2008 ◽  
Vol 571-572 ◽  
pp. 119-124 ◽  
Author(s):  
M. Rahman ◽  
Michael E. Fitzpatrick ◽  
Lyndon Edwards ◽  
S. Pratihar ◽  
Matthew J. Peel ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Aluminium Alloy ◽  
Crack Tip ◽  
Fatigue Loading ◽  
Compact Tension ◽  
European Synchrotron Radiation Facility ◽  
Stress Fields ◽  
Small Scale ◽  
X Ray Diffraction ◽  
X Ray

There have been many theoretical studies to predict the stress fields around the tip of a growing fatigue crack. However, until recently the highly-localized, small scale nature of the stresses has meant that direct measurement has not been possible. With the current generation of synchrotron X-ray sources, sub-millimetre sampling dimensions are now possible, and it has become possible to evaluate directly the stresses at the tip of a fatigue crack and to see how the stresses evolve as the result of an overload, for example. In this paper we present results of synchrotron X-ray diffraction analysis of the stress fields around a fatigue crack in aluminium alloy 5091 (Al-Mg-Li-C-O); this is a dispersion-strengthened alloy with a fine grain size, which makes it ideal for such experiments. Compact tension (CT) specimens were prepared with constant amplitude fatigue loading. The energy dispersive X-ray diffraction (EDXRD) technique was used for measuring strains around the crack tip along the mid thickness of the specimen under in-situ loading. The measurement was carried out at the ESRF (European Synchrotron Radiation Facility), Grenoble, France on the ID15A beam line. The experimental crack tip stresses have been compared with the analytical fracture mechanics solution.

Sign in / Sign up

Export Citation Format

Share Document