Sample Disturbance in Soft Alluvial Clyde Estuary Clay

1974 ◽  
Vol 11 (4) ◽  
pp. 651-660 ◽  
Author(s):  
A McGown ◽  
L. Barden ◽  
S. H. Lee ◽  
P. Wilby
Keyword(s):  
Shear Strength ◽  
Electron Microscope ◽  
Site Investigation ◽  
Triaxial Tests ◽  
Foundation Design ◽  
Site Investigations ◽  
Testing Techniques ◽  
Sample Disturbance ◽  
Area Standard ◽  
Scanning Electron

The alluvium of the Clyde Estuary provides the foundation material for a number of medium rise developments in the Glasgow area. Standard site investigation and testing techniques often result in an expensive foundation design involving piling. A more sophisticated investigation conducted at Laurieston, has afforded a chance to compare the disturbance due to different qualities of sampling. The degree of disturbance to macro- and microstructure has been assessed using standard photographic techniques and a scanning electron microscope. The effect of disturbance on shear strength has been measured using hand vane and triaxial tests; and on consolidation and compression parameters using Rowe cells of different sizes. On the basis of the standard and the improved site investigations two foundation designs have been prepared and their cost compared.

Microstructure and Shear Strength in Brazing Joint of Mo-Cu Composite with 304 Stainless Steel by Ni-Cr-P Filler Metal

2015 ◽  
Vol 34 (4) ◽  
Author(s):  
Juan Wang ◽  
Jiteng Wang ◽  
Yajiang Li ◽  
Deshuang Zheng
Keyword(s):  
Solid Solution ◽  
Stainless Steel ◽  
Shear Strength ◽  
Electron Microscope ◽  
Filler Metal ◽  
Energy Dispersive Spectrometer ◽  
Eutectic Structure ◽  
304 Stainless Steel ◽  
Steel Joint ◽  
Scanning Electron

AbstractThe brazing of Mo-Cu composite and 304 stainless steel was carried out in vacuum with Ni-Cr-P filler metal at 980 °C for 20 min. Microstructure in Mo-Cu/304 stainless steel joint was investigated by field-emission scanning electron microscope (FE-SEM) with energy dispersive spectrometer (EDS) and shear strength was measured by shearing test. The results indicate that shear strength of the Mo-Cu/304 stainless steel joint is about 155 MPa. There forms eutectic structure of γ-Ni solid solution with Ni

Shear Strength of Sn–3.5Ag Solder Bumps Formed on Ni/Au and Organic Solderability Preservative Surface-Finished Bond Pads After Multiple Reflow Steps

2005 ◽  
Vol 20 (11) ◽  
pp. 3088-3093
Author(s):  
Jung-Sub Lee ◽  
Kun-Mo Chu ◽  
Duk Young Jeon
Keyword(s):  
Shear Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Remarkable Change ◽  
Organic Solderability Preservative ◽  
Fracture Surfaces ◽  
Solder Bumps ◽  
Bond Pads ◽  
Electroless Ni ◽  
Scanning Electron

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.

The Microstructure of Dispersed and Flocculated Samples of Kaolinite, Illite, and Montmorillonite

1971 ◽  
Vol 8 (3) ◽  
pp. 391-399 ◽  
Author(s):  
Geoffrey Sides ◽  
Laing Barden
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Preliminary Investigation ◽  
Structural Effects ◽  
Chemical Dispersant ◽  
Natural Clays ◽  
Sample Disturbance ◽  
Scanning Electron

Samples of kaolinite, illite, and montmorillonite were consolidated from slurries containing chemical dispersant and flocculating agents. The resulting microstructures of the six clays so produced have been studied in the scanning electron microscope, following a preliminary investigation of the problems of sample disturbance during preparation for electron microscopy. It was seen that dispersed and salt-flocculated structures were formed in the illite clays as a result of their high colloidal activity, but that the inactive kaolinite was relatively insensitive to structural effects. The structures of these artificial clays are compatible with the limited results published on undisturbed natural clays. The small size of the montmorillonite particles led to difficulties in the preparation and scanning operations and no conclusions can be drawn for this clay.

scholarly journals In Situ Study on Fracture Behavior of Z-Pinned Carbon Fiber-Reinforced Aluminum Matrix Composite via Scanning Electron Microscope (SEM)

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1941
Author(s):  
Yunhe Zhang ◽  
Sian Wang ◽  
Xiwang Zhao ◽  
Fanming Wang ◽  
Gaohui Wu
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Electron Microscope ◽  
Carbon Fiber ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composite ◽  
Interlaminar Shear Strength ◽  
Interlaminar Shear ◽  
Scanning Electron

Inside a scanning electron microscope (SEM) chamber, we performed an in situ interlaminar shear test on a z-pinned carbon fiber-reinforced aluminum matrix composite (Cf/Al) fabricated by the pressure the infiltration method to understand its failure mechanism. Experiments show that introducing a stainless-steel z-pin increases the interlaminar shear strength of Cf/Al composite by 148%. The increase in interlaminar shear strength is attributed to the high strength of the stainless-steel z-pin and the strong bonding between the z-pin and the matrix. When the z-pin/matrix interface failed, the z-pin can still experience large shear deformation, thereby enhancing delamination resistance. The failure mechanism of composite includes interfacial debonding, aluminum plough, z-pin shear deformation, frictional sliding, and fracture. These results in this study will help us understand the interlaminar strengthening mechanism of z-pins in the delamination of metal matrix composites.

scholarly journals Shear strength properties of Hong Kong soils for slope stability

2020 ◽  
Vol 27 (1) ◽  
pp. 48-54
Author(s):  
Hong Yau Wong
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Slope Stability ◽  
Triaxial Compression ◽  
Quantitative Relationship ◽  
Site Investigation ◽  
Standard Penetration Test ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Soil Shear Strength

With the recent advancement in technology, the method, accuracy and speed of slope stability analysis have been vastly improved. Nevertheless, the reliability and appropriateness of such analysis can be very much in doubt if the soil behaviour, in particular the shear strength behaviour, is not fully understood. The objective of this paper is therefore to evaluate the shear strength behaviour of various soil types in Hong Kong. This comprises the collection, processing and analysis of the laboratory and field works carried out in the past few decades, in particular the triaxial compression testing in the laboratory and standard penetration test (SPT) in the field. For correlating SPT with soil shear strength, a fairly large number of carefully controlled site investigation works with SPT are carried out both above and below any Mazier sampling. Laboratory triaxial tests are then carried out in these Mazier samples. Finally, it is hoped that a basically quantitative relationship between soil shear strength and SPT can be obtained as this would enable a soil shear strength profile to be established once the corresponding SPT profile has been determined on site by carrying out SPT in adequate number of drill holes.

Study on the Mechanical Property of Cu-Filled Isotropically Conductive Adhesive/SiO2 Composites

2011 ◽  
Vol 239-242 ◽  
pp. 1068-1071
Author(s):  
Jian Hua Zhong ◽  
Zhi Hong Li ◽  
Ling Yu Ou Yang
Keyword(s):  
Mechanical Property ◽  
Shear Strength ◽  
Electron Microscope ◽  
Energy Dispersive Spectrometry ◽  
Adhesive Layer ◽  
Conductive Adhesive ◽  
Ft Ir ◽  
Isotropically Conductive Adhesive ◽  
Fractured Surface ◽  
Scanning Electron

Cu-filled isotropically conductive adhesive/SiO2 composites were prepared by direct-blending modified SiO2 into Cu-filled ICAs. The effects of different contents of SiO2 on the mechanical property were sdudied in this paper. The infrared spectra of the cured product between epoxy resin and imidazole was obtained with FT-IR. The surface morphology of the composite and its fractured surface after tensil test were observed by scanning electron microscope(SEM). In addition, energy dispersive spectrometry(EDS) was applied to analyze the distribution of Si in the adhesive layer. Experimental results showed that a small amount of SiO2 powders could evenly distribute in the Cu-filled ICAs, and as a reslut the mechanical property of Cu-filled ICA/SiO2 increased dramatically with the addition of SiO2. The best shear strength of the composite could reach up to 16.1MPa and 36.4% higher than the ICAs without addition SiO2 when the content of SiO2 was 3%.

Microstructural Evolution of AuSn20/Ni Joint during Annealing

2013 ◽  
Vol 634-638 ◽  
pp. 2865-2871 ◽  
Author(s):  
Xiao Feng Wei ◽  
Ri Chu Wang ◽  
Yan Feng
Keyword(s):  
Shear Strength ◽  
Electron Microscope ◽  
Melting Point ◽  
Mass Fraction ◽  
Eutectic Temperature ◽  
Solder Matrix ◽  
Reflow Process ◽  
X Ray ◽  
Annealing Method ◽  
Scanning Electron

The AuSn20 (mass fraction) solder was prepared by laminate rolling-annealing method, the AuSn20/Ni solder joints were prepared by the reflow process. The effects of the aging times and temperatures on the microstructure and shear strength of the AuSn20/Ni joints were investigated by the scanning electron microscope (SEM) with an energy dispersive X-ray (EDX). The results show that, the AuSn20 solder is composed of lamellar ζ-Au5Sn and δ-AuSn phases after preparing and the melting point approximates to the eutectic temperature of Au-20Sn alloy. A eutectic ζ-Au5Sn+δ-AuSn microstructure forms in the solder matrix and hexagon (Ni,Au)3Sn2 intermetallics nuclear at the as-reflowed joint. Then the AuSn20/Ni joint was aged at 150 and 200 °C for various times，and the thickness of the IMC layer at 150 °C changes few with the aging time increasing from 150 h to 1000 h, however, it grows rapidly at 200 °C.

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 176-177
Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Volume ◽  
Precipitate Morphology ◽  
Stress Rupture Life ◽  
Nickel Base ◽  
Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

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