Indentation Testing of an Al2O3/Al2O3 + ZrO2 Layered Composite

2005 ◽  
Vol 290 ◽  
pp. 316-319
Author(s):  
Peter Zimovčák ◽  
Tibor Köves ◽  
Ján Dusza ◽  
Ladislav Pešek ◽  
Francis Chalvet ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Residual Stresses ◽  
Size Effect ◽  
Vickers Hardness ◽  
Layered Composite ◽  
Indentation Load ◽  
Indentation Fracture ◽  
Depth Sensing ◽  
The Individual ◽  
Load Size

Micro- and macro-hardness of the individual layers of an Al2O3 / Al2O3 + ZrO2 layered composite have been investigated. The indentation load size effect has been studied in a range of indentation load of 25 mN – 100 N using depth sensing indentation technique and conventional Vickers hardness testers. Fracture toughness values of the layers have been measured using indentation fracture method. The effect of residual stresses on the KIC value has been analyzed.

scholarly journals Indentation Load-Size Effect in Al2O3 — SIC Nanocomposites

2010 ◽  
Vol 61 (5) ◽  
pp. 305-307 ◽  
Author(s):  
Erika CsehovAaA ◽  
Jana AndrejovskAaA ◽  
Apichart Limpichaipanit ◽  
Ján Dusza ◽  
Richard Todd
Keyword(s):  
Size Effect ◽  
Vickers Hardness ◽  
Indentation Load ◽  
Proportional Specimen Resistance ◽  
Load Size ◽  
Hardness Values ◽  
True Hardness

Indentation Load-Size Effect in Al2O3 — SIC Nanocomposites The indentation load-size effect (ISE) in Vickers hardness of Al2O3 and Al2O3 + SiC nanocomposites has been investigated and analysed using Meyer law, proportional specimen resistance (PSR) model and modified proportional specimen resistance (MPSR) model. The strongest ISE was found for alumina. Both the PSR and MPSR models described the ISE well, but the MPSR model resulted in slightly lower true hardness values for all materials investigated. No evidence of the effect of machining stresses on the ISE has been found.

Local Mechanical Properties of SiC - TiNbC Composite and its Constituents

2016 ◽  
Vol 368 ◽  
pp. 158-161 ◽  
Author(s):  
Martin Fides ◽  
Alexandra Kovalčíková ◽  
Pavol Hvizdoš ◽  
Richard Sedlák ◽  
Roman Bystrický ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elasticity Modulus ◽  
Indentation Fracture ◽  
Final Density ◽  
Indentation Fracture Toughness ◽  
The Individual ◽  
Composite Hardness ◽  
Load Size ◽  
Good Agreement

SiC based composite with 50 % of additives (Ti and NbC with ratio of 9:16) has been prepared. The microstructure, porosity, and chemical composition were studied using SEM equipped with EDS analyser. Local mechanical properties such a hardness and elastic modulus of individual components of the composite were investigated by nanoindentation using Berkovich indenter tip. Hardness and fracture toughness of studied material as a whole was evaluated by means of classic Vickers macroindentation. Indentation cracks were observed and their propagation was analyzed. It was shown that the present phases were distributed uniformly. Moreover, final density was satisfactory with porosity lower than 1 %. The individual constituents shown similar elasticity modulus (550 - 590 GPa). Hardness (HIT) exhibited very pronounced load-size effect. At 10 mN load, hardness was 42.33 GPa ± 1.1 GPa for SiC and 35.73 GPa ± 0.9 GPa for TiNbC, while at 500 mN the composite hardness was 27.61 GPa ± 0.505 GPa. It is in good agreement with macrohardness values, when 27.6 GPa and 25 GPa has been measured for 1 and 10 kg loads, respectively. Indentation fracture toughness was 3.3 MPa.m1/2 ± 0.22 MPa.m1/2. Electrical conductivity was measured by four point probes method and its value was 8.8×104 ± 0.3×104 Sm-1.

Measuring Residual Stress with the Indentation Method in Struc­tural Ceramics

2005 ◽  
Vol 297-300 ◽  
pp. 515-520
Author(s):  
Tarou Tokuda ◽  
Rong Gang Wang ◽  
Mitsuo Kido ◽  
Gonojo Katayama
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
Phase Transformation ◽  
Residual Stresses ◽  
Treatment Method ◽  
Indentation Load ◽  
X Rays ◽  
Ray Method ◽  
Indentation Method ◽  
X Ray

This study deals with the indentation method of measuring residual stress in structural ceramics. First we investigate the appropriate pretreatment for measuring fracture toughness (basis value, KC) while avoiding any influence from residual stress, which is important when estimating residual stress using the indentation method. Based on the fracture toughness value, the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics are estimated using the indentation method. Phase transformation is a problem when estimating residual stress using the indentation method with ZrO2 ceramics. Residual stresses in Al2O3 and Si3N4 can be largely eliminated by annealing the specimen after hand grinding. Consequently, it is thought that this treatment method is effective for determining the basis value KC. The estimated residual stress values in Al2O3 and Si3N4 obtained by the indentation method at 98 N corresponded closely to the values obtained wih X-rays. The residual stress value obtained by the indentation method for ZrO2 was close to the value obtained through the X-ray method, when the indentation load was 294 N. When estimating the residual stress in ZrO2 using the indentation method, the influence of the phase transformation caused by the indentation is added onto the original residual stress, when the indentation is small. The influence becomes smaller when the indentation load is large. If the applied indentation load is between 294 N and 490 N, the indentation method is effective for estimating the residual stresses in Al2O3, Si3N4 and ZrO2 ceramics.

Young׳s modulus, Vickers hardness and indentation fracture toughness of alumino silicate glasses

2015 ◽  
Vol 41 (6) ◽  
pp. 7267-7275 ◽  
Author(s):  
Mirko Tiegel ◽  
Reza Hosseinabadi ◽  
Stefan Kuhn ◽  
Andreas Herrmann ◽  
Christian Rüssel
Keyword(s):  
Fracture Toughness ◽  
Vickers Hardness ◽  
Silicate Glasses ◽  
Indentation Fracture ◽  
Indentation Fracture Toughness ◽  
Alumino Silicate

Nanohardness of Individual Phases in WC – Co Cemented Carbides

2013 ◽  
Vol 586 ◽  
pp. 23-26 ◽  
Author(s):  
Annamária Duszová ◽  
Radoslav Halgaš ◽  
Pavol Priputen ◽  
Marek Bľanda ◽  
Pavol Hvizdoš ◽  
...  
Keyword(s):  
Size Effect ◽  
Significant Influence ◽  
Crystallographic Orientation ◽  
Grain Orientation ◽  
Indentation Load ◽  
Cemented Carbides ◽  
Indentation Modulus ◽  
Instrumented Indentation ◽  
Load Size

The nanohardness of WC – Co hardmetals has been investigated using instrumented indentation and Berkovich tip indenter. The nanohardness, HIT, and indentation modulus, EIT, of Co phase and individual WC grains and the influence of their crystalographic orientation have been studied. SEM, AFM and EBSD methods were used for the characterization of the microstructures and indents and for the identification of crystallographic orientation of WC grains, respectively. Strong indentation load-size effect and significant influence of the crystallographic orientation of WC crystals on HIT and EIT have been found. The nanohardness of Co binder was approximately 10 GPa and that of WC grains varied between 25 and 50 GPa, depending on the grain orientation and load. The nanohardness values of the basal and prismatic planes of individual WC grains at load of 10 mN were 40.4 ± 1.6 GPa and 32.8 ± 2.0 GPa, respectively.

Fracture Toughness of Ceramic Materials and Its Relationship to Chipping Formation

2005 ◽  
Vol 290 ◽  
pp. 39-45
Author(s):  
Zdenĕk Jonšta ◽  
Jana Horváthová ◽  
Kateřina Blažková ◽  
Karel Mazanec
Keyword(s):  
Fracture Toughness ◽  
Ceramic Materials ◽  
Indentation Load ◽  
Load Level ◽  
Beam Specimen ◽  
Indentation Fracture ◽  
Fracture Toughness Measurement ◽  
Chip Fracture ◽  
Indentation Fracture Toughness ◽  
Basic Parameters

The work is devoted to the evaluation of indentation fracture toughness in ceramic materials and to the comparison of these data with the results of this characterisation obtained by the application of fracture mechanics method (chevron notched beam specimen – CVNB). The indentation fracture toughness measurement is realized using the indentation load lying in the loading extent between 50-300 N. The evaluation of basic parameters of lateral crack initiation resulting in chipping formation in the vicinity of indent is performed. This measuring is based on the finding of relationship between the indent load level and the number of loading cycles leading to chips formation. The geometry of lateral cracks and chipping morphology are described. This evaluation is complemented with the analysis of chip fracture surfaces.

Hardness and indentation load-size effect in Al2O3-SiC nanocomposite

2011 ◽  
Vol 49 (2) ◽  
pp. 119-124 ◽  
Author(s):  
E. CSEHOVA ◽  
J. ANDREJOVSKA ◽  
A. LIMPICHAIPANIT ◽  
J. DUSZA ◽  
R. TODD
Keyword(s):  
Size Effect ◽  
Indentation Load ◽  
Load Size

Indentation Testing of MoSi2

2005 ◽  
Vol 290 ◽  
pp. 288-291 ◽  
Author(s):  
M. Henžel ◽  
Peter Zimovčák ◽  
Ján Dusza ◽  
András Juhász ◽  
Janos Lendvai
Keyword(s):  
High Temperature ◽  
Indentation Load ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Slip Systems ◽  
Deformation Characteristics ◽  
Depth Sensing ◽  
Indentation Methods ◽  
Load Size ◽  
Hardness Values

Indentation methods have been used for the study of the hardness and deformation characteristics MoSi2. Micro-nanoindentation tests at loads from 10 mN to 2000 mN were carried out using the depth-sensing method. Measurements of the microhardness using conventional Vickers method was carried out at loads of 500 mN, 1000 mN and 2000 mN. The Universal (Martens), Plastic and conventional Vickers hardness values were calculated at different indentation loads. Evident indentation load - size effect was found in both materials. According to the results, the pre-strain reduces the micro-nano hardness values, probably due to the activation of slip systems during the high-temperature deformation.

scholarly journals Analyzing Time on Sample During Nanoindentation

2016 ◽  
Vol 13 (2) ◽  
pp. 74-79 ◽  
Author(s):  
A. S. Bhattacharyya ◽  
P Kumar ◽  
N Rajak ◽  
R.P Kumar ◽  
A Sharma ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Significant Contribution ◽  
Substrate Effect ◽  
Failure Zone ◽  
Indentation Fracture ◽  
Depth Sensing ◽  
Indentation Fracture Toughness ◽  
Depth Curves

Nanoindentation is an effective way of finding mechanical properties at nanoscale. They are especially useful for thin films where elimination of the substrate effect is required. The mechanism is based upon depth sensing indentation based on Oliver and Pharr modeling. The load-depth curves as well as time on sample were analyzed. Indentation impulse was found to have significant contribution in the nature of failure zone during indentation. Fracture toughness was also related to time on the sample.

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