Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Phase Transformation Cycle β→ α′ + α + α"→ β in Ti6Al4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 232-238 ◽  
Author(s):  
Kalenda Mutombo ◽  
Siyasiya Charles ◽  
Waldo Stumpf
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Phase Field ◽  
Xrd Analysis ◽  
External Stress ◽  
Ti6al4v Alloy ◽  
Β Phase ◽  
Α Phase ◽  
Sequential Transformation ◽  
Dsc Thermograms

The β-phase transforms to α′, α and α" within a range of temperature from the β-transus (Tβ) to about 600°C, considering no external stress is applied. Two types of microstructure were obtained: acicular martensite when rapidly cooled and lamellar α/β when slowly cooled from the β phase field. The sequential transformation of β into α′, α-phase, α2, and α" was revealed as peaks on the coefficient thermal expansion (CTE) curves, however, reversed transformations: α"→β, and α→β, were revealed by the DSC thermograms. The presence of β, α′, α, α2 and α" was identified by means of XRD analysis and HRTEM.

Effect of Thermal Expansion Mismatch on Fiber Pull-out in Glass Matrix Composites

1988 ◽  
Vol 120 ◽  
Author(s):  
U. V. Deshmukh ◽  
A. Kanei ◽  
S. W. Freiman ◽  
D. C. Cranmer
Keyword(s):  
Thermal Expansion ◽  
Silica Glass ◽  
Glass Matrix ◽  
Soda Lime ◽  
Matrix Composites ◽  
Thermal Expansion Mismatch ◽  
Pull Out ◽  
Soda Lime Silica Glass ◽  
Fiber Matrix ◽  
Glass Matrix Composites

AbstractSingle fiber pull-out tests can be used to directly measure the fiber-matrix interfacial shear stress in glass matrix composites. The system under investigation consisted of a soda-lime-silica glass matrix containing SiC monofilaments with a carbon-rich surface. The presence of the carbon-rich layer on the surface of these fibers makes them non-wetting to most glasses; hence the fibers are held in the matrix only by frictional forces acting at the interface. The mechanical gripping responsible for this force can be changed by manipulating the glass matrix/fiber thermal expansion coefficient mismatch. Frictional stresses (τ) and friction coefficients (μ) obtained for SiC monofilaments in a soda-lime-silica glass matrix were compared with previously obtained data on a borosilicate glass matrix (τ = 2–3 MPa, μ = 0.72 ± 0.36). For the soda-lime-silica system, τ's of 4–20 MPa and μ of 0.10 ± 0.03 were obtained. τ in the soda-lime-silica system is higher due to the larger difference in thermal expansion mismatch between the fiber and matrix. The differences in μ may be due to lubrication effects caused by water at the fiber-matrix interface.

scholarly journals XAFS characterization of industrial catalysts:in situstudy of phase transformation of nickel sulfide

2016 ◽  
Vol 712 ◽  
pp. 012145 ◽  
Author(s):  
J Wang ◽  
Z Jia ◽  
Q Wang ◽  
S Zhao ◽  
Z Xu ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Nickel Sulfide

Phase Transformation In Ti-6al-4v Alloys

1972 ◽  
Vol 30 ◽  
pp. 584-585
Author(s):  
Shiro Fujishiro
Keyword(s):  
Phase Transformation ◽  
Grain Boundary ◽  
Cryogenic Temperature ◽  
Β Phase ◽  
Heat Treated ◽  
Mixed Microstructure ◽  
Ductile Behavior

The Ti-6 wt.% Al-4 wt.% V commercial alloys have exhibited an improved formability at cryogenic temperature when the alloys were heat-treated prior to the tests. The author was interested in further investigating this unusual ductile behavior which may be associated with the strain-induced transformation or twinning of the a phase, enhanced at lower temperatures. The starting materials, supplied by RMI Co., Niles, Ohio were rolled mill products in the form of 40 mil sheets. The microstructure of the as-received materials contained mainly ellipsoidal α grains measuring between 1 and 5μ. The β phase formed an undefined grain boundary around the a grains. The specimens were homogenized at 1050°C for one hour, followed by aging at 500°C for two hours, and then quenched in water to produce the α/β mixed microstructure.

scholarly journals In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

2016 ◽  
Vol 108 (21) ◽  
pp. 211902 ◽  
Author(s):  
Xian Chen ◽  
Nobumichi Tamura ◽  
Alastair MacDowell ◽  
Richard D. James
Keyword(s):  
Phase Transformation ◽  
In Situ Characterization ◽  
X Ray ◽  
Reversible Phase ◽  
Laue Microdiffraction

scholarly journals Unravelling thermal stress due to thermal expansion mismatch in metal–organic frameworks for methane storage

2021 ◽  
Author(s):  
Jelle Wieme ◽  
Veronique Van Speybroeck
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Pressure Coefficient ◽  
Metal Organic Frameworks ◽  
Methane Storage ◽  
Thermal Expansion Mismatch ◽  
Thermal Pressure ◽  
Temperature Changes ◽  
Metal Organic ◽  
The Impact

Thermal stress is present in metal–organic frameworks undergoing temperature changes during adsorption and desorption. We computed the thermal pressure coefficient as a proxy for this phenomenon and discuss the impact of thermal expansion mismatch.

γ→β phase transformation in Ti-42.9Al-4.6Nb–2Cr

2021 ◽  
Vol 133 ◽  
pp. 107169
Author(s):  
R.R. Xu ◽  
M.Q. Li
Keyword(s):  
Phase Transformation ◽  
Β Phase
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