scholarly journals Indentation Fracture of Brittle Materials

1990 ◽  
Vol 188 ◽  
Author(s):  
Barry N. Lucas ◽  
W. C. Oliver ◽  
J. J. Wert
Keyword(s):  
Single Crystal ◽  
Continuous Monitoring ◽  
Brittle Materials ◽  
Soda Lime ◽  
Fused Silica ◽  
Soda Lime Glass ◽  
Displacement Curve ◽  
Indentation Fracture ◽  
Load Displacement ◽  
Transparent Materials

ABSTRACTThe response of four transparent materials, soda-lime glass, fused silica, single crystal (0001) A12O3, and Y2O3-ZrO2, to contact by a sharp indenter has been studied. Insitu observation and continuous monitoring of the load and displacement throughout the test allowed the indentation fracture sequence of the transparent materials to be characterized and also permitted the effects of these fracture events on the corresponding load displacement curves to be noted. It was found that if the cracks produced during indentation grew discontinuously, they manifested themselves in discontinuities in displacement on the corresponding load-displacement curve.

An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments

1992 ◽  
Vol 7 (6) ◽  
pp. 1564-1583 ◽  
Author(s):  
W.C. Oliver ◽  
G.M. Pharr
Keyword(s):  
Elastic Modulus ◽  
Peak Load ◽  
Soda Lime ◽  
Indentation Load ◽  
Fused Silica ◽  
Soda Lime Glass ◽  
Flat Punch ◽  
Analysis Technique ◽  
Load Displacement ◽  
Improved Technique

The indentation load-displacement behavior of six materials tested with a Berkovich indenter has been carefully documented to establish an improved method for determining hardness and elastic modulus from indentation load-displacement data. The materials included fused silica, soda–lime glass, and single crystals of aluminum, tungsten, quartz, and sapphire. It is shown that the load–displacement curves during unloading in these materials are not linear, even in the initial stages, thereby suggesting that the flat punch approximation used so often in the analysis of unloading data is not entirely adequate. An analysis technique is presented that accounts for the curvature in the unloading data and provides a physically justifiable procedure for determining the depth which should be used in conjunction with the indenter shape function to establish the contact area at peak load. The hardnesses and elastic moduli of the six materials are computed using the analysis procedure and compared with values determined by independent means to assess the accuracy of the method. The results show that with good technique, moduli can be measured to within 5%.

Scanning tunneling microscope observations of the mirror region of silicate glass fracture surfaces

1994 ◽  
Vol 9 (2) ◽  
pp. 476-485 ◽  
Author(s):  
D.M. Kulawansa ◽  
L.C. Jensen ◽  
S.C. Langford ◽  
J.T. Dickinson ◽  
Yoshihisa Watanabe
Keyword(s):  
Scanning Tunneling Microscope ◽  
Soda Lime ◽  
Local Deformation ◽  
Fused Silica ◽  
Scanning Tunneling ◽  
Soda Lime Glass ◽  
Self Similarity ◽  
Tunneling Microscope ◽  
Fracture Surfaces ◽  
Mirror Region

We report scanning tunneling microscope images of gold-coated fracture surfaces of soda lime glass and fused silica in the mirror region. The scans show a variety of nanometer scale features that are attributed to fracture phenomena at this scale. We find considerable similarity to the structures observed in regions of extensive crack branching (e.g., “mist”). The density of these features increases as one progresses away from the crack origin toward the mirror-mist boundary. Comparisons are made between soda lime glass and fused silica, revealing differences in the local deformation behavior of these two materials. Self-similarity of the observed structures is probed by measurements of the fractal dimension, Df, of the surfaces created in soda lime glass near the mirror-mist boundary, where we observe 2.17 > Df > 2.40.

AFM Study of Surface Morphology of Aluminum Nitride Thin Films

1995 ◽  
Vol 388 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura ◽  
Shigekazu Hirayama ◽  
Yuusaku Naota
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Ion Beam ◽  
Soda Lime ◽  
Silicon Single Crystal ◽  
Soda Lime Glass ◽  
Average Roughness

AbstractAluminum nitride (AlN) thin films have been synthesized by ion-beam assisted deposition method. Film deposition has been performed on the substrates of silicon single crystal, soda-lime glass and alumin A. the influence of the substrate roughness on the film roughness is studied. the substrate temperature has been kept at room temperature and 473K and the kinetic energy of the incident nitrogen ion beam and the deposition rate have been fixed to 0.5 keV and 0.07 nm/s, respectively. the microstructure of the synthesized films has been examined by X-ray diffraction (XRD) and the surface morphology has been observed by atomic force microscopy(AFM). IN the XRD patterns of films synthesized at both room temperature and 473K, the diffraction line indicating the alN (10*0) can be discerned and the broad peak composed of two lines indicating the a1N (00*2) and a1N (10*1) planes is also observed. aFM observations for 100 nm films reveal that (1) the surface of the films synthesized on the silicon single crystal and soda-lime glass substrates is uniform and smooth on the nanometer scale, (2) the average roughness of the films synthesized on the alumina substrate is similar to that of the substrate, suggesting the evaluation of the average roughness of the film itself is difficult in the case of the rough substrate, and (3) the average roughness increases with increasing the substrate temperature.

Research on the Relationship between Indenter Tip Radius and Hardness with a Self-Designed Nanohardness Test Device

2008 ◽  
Vol 392-394 ◽  
pp. 267-270
Author(s):  
Qiang Liu ◽  
Ying Xue Yao ◽  
L. Zhou
Keyword(s):  
Single Crystal ◽  
Indentation Depth ◽  
Single Crystal Silicon ◽  
Indentation Hardness ◽  
Displacement Curve ◽  
Test Device ◽  
Crystal Silicon ◽  
Load Displacement ◽  
Depth Sensitivity ◽  
Tip Radius

Nanoindentation device has the ability to make the load-displacement measurement with sub-nanometer indentation depth sensitivity, and the nanohardness of the material can be achieved by the load-displacement curve. Aiming at the influence law of indenter tip radius to indentation hardness, testing on the hardness of single-crystal silicon were carried out with the new self-designed nanohardness test device based on nanoindentation technique. Two kinds of Berkovich indenter with radius 40nm and 60nm separately were used in this experiment. According to the load-depth curve, the hardness of single-crystal silicon was achieved by Oliver-Pharr method. Experimental results are presented which show that indenter tip radius do influence the hardness, the hardness value increases and the indentation size effect (ISE) becomes obvious with the increasing of tip radius under same indentation depth.

Indentation-induced deformation at ultramicroscopic and macroscopic contacts

2004 ◽  
Vol 19 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Jeremy Thurn ◽  
Robert F. Cook
Keyword(s):  
Plastic Deformation ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Depth Sensing ◽  
Paraboloid Of Revolution ◽  
Loading And Unloading ◽  
Load Displacement ◽  
Elastic And Plastic Deformation ◽  
Tip Radius ◽  
Unloading Stiffness

Depth-sensing indentation at ultramicroscopic and macroscopic contacts (“nanoindentation” and “macroindentation,” respectively) was performed on four brittle materials (soda-lime glass, alumina titanium carbide, sapphire, and silicon) and the resulting load–displacement traces examined to provide insight to the elastic and plastic deformation scaling with contact size. The load–displacement traces are examined in terms of the unloading stiffness, the energies deposited during loading and recovered on unloading, and the effect of the indenter tip radius on the loading curve. The results of the analyses show that the elastic and plastic deformation during loading and unloading is invariant with the scale of the contact, and the unloading curve is best described by neither a conical tip nor a paraboloid of revolution, but of some compromise.

Photo-oxidatively self-cleaning transparent titanium dioxide films on soda lime glass: The deleterious effect of sodium contamination and its prevention

1997 ◽  
Vol 12 (10) ◽  
pp. 2759-2766 ◽  
Author(s):  
Y. Paz ◽  
A. Heller
Keyword(s):  
Titanium Dioxide ◽  
Sodium Transport ◽  
Anatase Phase ◽  
Soda Lime ◽  
Fused Silica ◽  
Precursor Film ◽  
Soda Lime Glass ◽  
Blocking Layer ◽  
High Concentration ◽  
Self Cleaning

In the context of photocatalytically self-cleaning windows and windshields, clear, abrasion resistant, thin (60 ± 10 nm) photocatalytic films of TiO2 were formed by a sol-gel process on (a) soda lime glass, (b) the proton-exchanged surface of soda lime glass, and (c) fused silica. The hypothesis that diffusion of sodium oxide from the soda lime glass into the titanium dioxide layer during the calcination step causes the lower photoefficiency in films on glass was tested and proven. At high concentration sodium prevented formation of the photoactive anatase phase and, at low concentration, introduced surface and bulk recombination centers. Sodium transport was efficiently blocked by a thin layer at the interface of proton-exchanged (“hydrogen”) glass and nascent TiO2, formed at 400 °C of a poly(titanyl acetylacetonate) TiO2 precursor. The sodium transport blocking layer did not form and the highly photocatalytic film was not obtained when the TiO2-precursor film was applied to glass that was not proton exchanged. Furthermore, only a much less effective sodium transport blocking layer was formed on glass that was proton-exchanged, but was calcined at 400 °C prior to application of the TiO2 precursor layer, showing that the sodium depleted glass surface, by itself, was a less effective barrier against sodium transport than the interfacial product of hydrogen glass and the TiO2 precursor.

Microscratch Analysis of The Adhesion Failure on Oxide Thin Films With Different Thickness

1996 ◽  
Vol 436 ◽  
Author(s):  
C. R. Ottermann ◽  
K. Bange ◽  
A. Braband ◽  
H. Haefke ◽  
W. Gutmannsbauer
Keyword(s):  
Thin Films ◽  
Chemical Vapour ◽  
Soda Lime ◽  
Fused Silica ◽  
Soda Lime Glass ◽  
Test Results ◽  
Glass Substrates ◽  
Adhesion Failure ◽  
Different Thickness ◽  
Deposition Techniques

AbstractAdhesion failures of Ti2 and Ta2O5 thin films deposited by reactive evaporation (RE), reactive ion plating (IP) and plasma impulse chemical vapour deposition (PICVD) on fused silica, AF 45, TEMPAX and soda-lime glass substrates are investigated by means of a micro-scratch tester. The oxide films possess thickness between 60 and 500 nm and show different mass densities depending on the deposition conditions. Scratch testing exhibits well pronounced detachment for thicker films on hard substrates. The clearance of the scratch signal is reduced with decreasing layer thickness or for softer substrate materials. The test results are also influenced by the various substrates and different chemical and mechanical properties of the films due to the alternate deposition techniques.

Stress Induced Extended Ranges for Hydration and Other Phenomena in Ion Implanted Silica Glasses

1996 ◽  
Vol 438 ◽  
Author(s):  
G. W. Arnold ◽  
G. Battaglin
Keyword(s):  
Stress Corrosion ◽  
Water Immersion ◽  
Soda Lime ◽  
Fused Silica ◽  
Soda Lime Glass ◽  
Ambient Atmosphere ◽  
Near Surface ◽  
Silica Glasses ◽  
Property Changes ◽  
Ion Implanted

AbstractThe extended ranges (2–3 times theoretical) for hydration from an ambient atmosphere or water immersion and other anomalous ranges for property changes in ion-implanted fused silica are explained on the basis of a stress corrosion model (Michalske-Bunker). The results for the hydration of implanted soda-lime glass are similar to fused silica with the added feature of compositional modification due to the near-surface removal of alkali.

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