The Study of Fracture Surfaces With the Scanning Electron Microscope

1969 ◽  
Author(s):  
Om Johari
2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Z. Z. Zhang

Experiments on granite specimens after different high temperature under uniaxial compression were conducted and the fracture surfaces were observed by scanning electron microscope (SEM). The fractal dimensions of the fracture surfaces with increasing temperature were calculated, respectively. The fractal dimension of fracture surface is between 1.44 and 1.63. Its value approximately goes up exponentially with the increase of temperature. There is a quadratic polynomial relationship between the rockburst tendency and fractal dimension of fracture surface; namely, a fractal dimension threshold can be obtained. Below the threshold value, a positive correlativity shows between rockburst tendency and fractal dimension; when the fractal dimension is greater than the threshold value, it shows an inverse correlativity.


Author(s):  
Osamu Watanabe ◽  
Marina Kikuchi ◽  
Akihiro Matsuda

Fatigue crack propagation forms a distinctive pattern which is observable on the fracture surfaces of materials. Purpose of this study is to analyze the fracture process of the materials received under cyclic distortion loading using scanning electron microscope. The test piece made of type 304 stainless steel with the hole of a different size is examined on the conditions of the high temperature fatigue and creep-fatigue. This study first takes a picture of the fracture with SEM, and measures the intervals of striation on fracture surfaces. Next, this study calculates the number of the crack propagation cycles and compares with the original experimental data defined by the load decrease condition or the crack length. Consequently, there is not so much differences at striation intervals regardless of the size of the root notch radius in the present tests. However, the striation spacing in the creep fatigue test has grown about twice of striation intervals in the high temperature fatigue-test.


2005 ◽  
Vol 20 (11) ◽  
pp. 3088-3093
Author(s):  
Jung-Sub Lee ◽  
Kun-Mo Chu ◽  
Duk Young Jeon

Sn–3.5Ag solder bumps were formed on electroless Ni/immersion Au (Ni/Au) and organic solderability preservative (OSP) surface-finished bond pads, respectively. The shear strength of the solder bumps was measured as a function of reflow steps. Fracture surfaces and interfacial microstructures were investigated by scanning electron microscope. The shear strength of Ni/Au samples increased up to the seventh reflow step and subsequently decreased after the tenth reflow step. Spalling of Ni3Sn4 intermetallic compounds (IMCs) and the P-rich Ni layer strengthened and weakened the bond, respectively. For OSP samples, although Cu6Sn5 IMCs grew as the reflow step was repeated, no remarkable change in shear strength was observed. Interfacial fractures of OSP samples occurred at the interface between Cu6Sn5 IMC and Cu3Sn IMC. Fracture surfaces of OSP samples showed concave pits that consisted of a Cu3Sn bottom and an Sn wall. The pits were formed by separation of Cu6Sn5 IMC from Cu3Sn IMC and the molten Sn channel between the Cu6Sn5 IMC grains.


1994 ◽  
Vol 370 ◽  
Author(s):  
S. Mindess ◽  
S. Diamond

AbstractStereo pair imaging in a scanning electron microscope was used to document the details ofthe topography of fracture surfaces at various degrees of magnification. The fracture surfaces had been produced by fracture testing of chevron-notched beam specimens according to ISRM Method I. The surfaces examined included the fracture surfaces of dolomite and andesite rocks, cement pastes with and without silica fume, the fracture surfaces from specimen prepared by casting cement paste on previously fractured rock specimen faces, and the fracture surfaces of mortars prepared using the same rock types and cement pastes. The principal topographic features of the various fracture surfaces are described.


2014 ◽  
Vol 782 ◽  
pp. 449-452 ◽  
Author(s):  
Monika Losertová ◽  
Jaromír Drápala ◽  
Kateřina Konečná ◽  
Leopold Pleva

The study of microstructure and fracture surfaces was performed on specimens of reconstruction plate, reconstruction nail and elastic nail. The composition and phase analysis of microstructure was performed by scanning electron microscope (SEM) JEOL JSM - 6490LV equipped with EDS INCA X - ACT probe. Examination of fracture surfaces by SEM confirmed that damage was not simply due to fatigue but contained evidence of corrosion and mechanical fretting as well.


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