Failure analysis of ParaPost drills that fractured in service: a retrieval analysis study

2016 ◽  
Vol 61 (5) ◽  
Author(s):  
Youssef S. Al Jabbari ◽  
Raymond Fournelle ◽  
Mirae Al Qhatani ◽  
Spiros Zinelis

AbstractThe aim was to determine the fracture mechanism of two clinically failed ParaPost drills. First, the fracture planes were analyzed by scanning electron microscopy (SEM). The drill end of one of the fractured pieces of each drill was then embedded in resin and after being metallographically ground and polished, was chemically etched. The microstructure and elemental composition were then examined by SEM/EDS analysis while hardness was determined with a Vickers testing device. Fractographic analysis revealed that both drills failed in a brittle manner and showed a pattern characteristic of a

2017 ◽  
Vol 23 (3) ◽  
pp. 679-686 ◽  
Author(s):  
Milan Gavrilović ◽  
Suzana Erić ◽  
Petar D. Marin ◽  
Núria Garcia-Jacas ◽  
Alfonso Susanna ◽  
...  

AbstractIn this work, weddellite and sylvite crystals are identified for the first time on the involucral bracts and petals of Xeranthemum annuum and Xeranthemum cylindraceum using scanning electron microscopy coupled with energy dispersive spectrometric (SEM-EDS) analysis. Well-developed crystals of weddellite (CaC2O4·2H2O) occur in the form of a tetragonal bipyramid (hhl), rarely in combination of a bipyramid and tetragonal prism (h00). Indumentum of involucral bracts of X. cylindraceum consists of nonglandular and glandular trichomes. Sylvite (KCl) crystals are observed only on the petal surface of X. cylindraceum. The crystals of sylvite occur in the form of perfect cubes (hexahedrons), but some crystals are deformed, i.e., partially elongated. Taxonomic significance of investigated microcharacters as well as the use of SEM-EDS analysis in taxonomic studies of plants are discussed.


2014 ◽  
Vol 971-973 ◽  
pp. 802-805
Author(s):  
Wei Feng Zhang ◽  
Li Yan ◽  
Fu Xia Zhang

For the problem of high-speed rotating centrifuge spindle fracture failures, relevant analyses are conducted from the perspective of microstructure, chemical composition and fracture mechanics by using scanning electron microscopy and related instruments. Experimental results and analyses indicate that the spindle fracture is fatigue failure, mainly caused by cold cracks generated on the journal surfacing. Based on the analysis results, improvements and measures are suggested to better solve the spindle weld fracture failure problems.


2020 ◽  
Vol 34 (7) ◽  
pp. 8848-8856
Author(s):  
Elena V. Fomenko ◽  
Vladimir V. Yumashev ◽  
Sergey V. Kukhtetskiy ◽  
Anatoliy M. Zhizhaev ◽  
Alexander G. Anshits

1967 ◽  
Vol 6 (1) ◽  
pp. 9-16 ◽  
Author(s):  
P.R. Thornton ◽  
K.A. Hughes ◽  
Htin Kyaw ◽  
C. Millward ◽  
D.V. Sulway

2018 ◽  
Vol 773 ◽  
pp. 287-291
Author(s):  
Eui Soo Kim

High-pressure gas containers must be able to withstand high internal pressures because they store compressed gases. Otherwise, cracks or defects may lead to an explosion, which may in turn lead to a large-scale disaster. Therefore, accurate analysis of the causes of cracks or defects and various techniques for detecting cracks or defects are needed. In this research, we analyzed the failure mechanism of a high-pressure gas container through fractography using scanning electron microscopy and optical microscopy and through measurements of their mechanical and chemical properties.


1969 ◽  
Vol 8 (1) ◽  
pp. 33-53 ◽  
Author(s):  
P.R. Thornton ◽  
I.G. Davies ◽  
D.A. Shaw ◽  
D.V. Sulway ◽  
R.C. Wayte

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