Study of analysis methods of depth-sensing indentation test data for spherical indenters

2001 ◽  
Vol 16 (6) ◽  
pp. 1579-1584 ◽  
Author(s):  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Test Data ◽  
Indentation Test ◽  
Spherical Indenter ◽  
Depth Sensing ◽  
Formal Treatment ◽  
Underlying Theory ◽  
Analysis Methods ◽  
Load Displacement

The underlying theory behind the extraction of elastic modulus and hardness from the unloading load–displacement data obtained with a spherical indenter was explored in detail. A formal treatment of the effect of indenter elasticity was given, and the validity of the use of the reduced or combined modulus in analytical treatments was verified. The “Oliver and Pharr” method and the “Field and Swain” methods of analyses were compared in detail and shown to be equivalent.

Simulation of sub-micron indentation tests with spherical and Berkovich indenters

2001 ◽  
Vol 16 (7) ◽  
pp. 2149-2157 ◽  
Author(s):  
A. C. Fischer-Cripps
Keyword(s):  
Experimental Data ◽  
Elastic Modulus ◽  
Material Properties ◽  
Indentation Testing ◽  
Depth Sensing ◽  
Displacement Response ◽  
Analysis Methods ◽  
Detailed Treatment ◽  
Indentation Tests ◽  
Load Displacement

The present work is concerned with the methods of simulation of data obtained from depth-sensing submicron indentation testing. Details of analysis methods for both spherical and Berkovich indenters using multiple or single unload points are presented followed by a detailed treatment of a method for simulating an experimental load–displacement response where the material properties such as elastic modulus and hardness are given as inputs. A comparison between simulated and experimental data is given.

Use of combined elastic modulus in depth-sensing indentation with a conical indenter

2003 ◽  
Vol 18 (5) ◽  
pp. 1043-1045 ◽  
Author(s):  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Test Data ◽  
Data Use ◽  
Indentation Test ◽  
Indentation Testing ◽  
Depth Sensing ◽  
Conical Indenter ◽  
Displacement Response ◽  
Conventional Methods ◽  
Elastic Unloading

Conventional methods of analysis for depth-sensing indentation test data use the slope of the elastic unloading portion of the load–displacement response in conjunction with the elastic equations of contact for a rigid cone. It is common practice to incorporate the combined modulus of the indenter and specimen in these equations although the validity of this practice never appears to have been verified. This work demonstrates the validity of using the combined elastic modulus in depth-sensing indentation testing in conjunction with the elastic equations of contact for a conical indenter.

scholarly journals Analysis of depth-sensing indentation tests with a Knoop indenter

2001 ◽  
Vol 16 (6) ◽  
pp. 1660-1667 ◽  
Author(s):  
L. Riester ◽  
T. J. Bell ◽  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Elastic Recovery ◽  
Indentation Test ◽  
New Method ◽  
Short Axis ◽  
Depth Sensing ◽  
Specimen Material ◽  
Indentation Tests ◽  
Conventional Methods ◽  
Knoop Indenter

The present work shows how data obtained in a depth-sensing indentation test using a Knoop indenter may be analyzed to provide elastic modulus and hardness of the specimen material. The method takes into account the elastic recovery along the direction of the short axis of the residual impression as the indenter is removed. If elastic recovery is not accounted for, the elastic modulus and hardness are overestimated by an amount that depends on the ratio of E/H of the specimen material. The new method of analysis expresses the elastic recovery of the short diagonal of the residual impression into an equivalent face angle for one side of the Knoop indenter. Conventional methods of analysis using this corrected angle provide results for modulus and hardness that are consistent with those obtained with other types of indenters.

Influences of pileup on the measurement of mechanical properties by load and depth sensing indentation techniques

1998 ◽  
Vol 13 (4) ◽  
pp. 1049-1058 ◽  
Author(s):  
A. Bolshakov ◽  
G. M. Pharr
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Indentation Load ◽  
Depth Sensing ◽  
Element Mesh ◽  
Plastic Materials ◽  
Element Simulation ◽  
Load Displacement ◽  
Elastic Plastic Materials ◽  
True Contact

Finite element simulation of conical indentation of a wide variety of elastic-plastic materials has been used to investigate the influences of pileup on the accuracy with which hardness and elastic modulus can be measured by load and depth-sensing indentation techniques. The key parameter in the investigation is the contact area, which can be determined from the finite element results either by applying standard analysis procedures to the simulated indentation load-displacement data, as would be done in an experiment, or more directly, by examination of the contact profiles in the finite element mesh. Depending on the pileup behavior of the material, these two areas may be very different. When pileup is large, the areas deduced from analyses of the load-displacement curves underestimate the true contact areas by as much as 60%. This, in turn, leads to overestimations of the hardness and elastic modulus. The conditions under which the errors are significant are identified, and it is shown how parameters measured from the indentation load-displacement data can be used to identify when pileup is an important factor.

Use of combined elastic modulus in the analysis of depth-sensing indentation data

2001 ◽  
Vol 16 (11) ◽  
pp. 3050-3052 ◽  
Author(s):  
A. C. Fischer-Cripps
Keyword(s):  
Elastic Modulus ◽  
Test Data ◽  
Nanoindentation Test ◽  
Depth Sensing ◽  
True Value ◽  
Methods Of Analysis ◽  
Reduced Modulus ◽  
Unloading Stiffness ◽  
Depth Response

It is shown that the substitution of reduced modulus for specimen modulus in the analysis equations for nanoindentation test data is valid. The methods of analysis use the slope of the unloading force–depth response which is assumed to be elastic. Because of this utilization of the slope or unloading stiffness, it makes no difference whether or not the deflection of the indenter is accommodated explicitly or transferred to that occurring within the specimen by artificially reducing the specimen modulus from its true value to lower value, the reduced modulus.

Modelling the nano indentation behaviour of recast layer and heat affected zone on reverse micro EDMed hemispherical feature

2021 ◽  
pp. 1-15
Author(s):  
Tribeni Roy ◽  
Anuj Sharma ◽  
Prabhat Ranjan ◽  
R. Balasubramaniam
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Heat Affected Zone ◽  
Parent Material ◽  
Recast Layer ◽  
Machined Surface ◽  
Nano Indentation ◽  
Fea Simulation ◽  
Load Displacement ◽  
Good Agreement

Abstract Electrical discharge machined surfaces inherently possess recast layer on the surface with heat affected zone (HAZ) beneath it and these have a detrimental effect on the mechanical properties viz. hardness, elastic modulus, etc. It is very difficult to experimentally characterise each machined surface. Therefore, an attempt is made in this study to numerically calculate the mechanical properties of the parent material, HAZ and the recast layer on a hemispherical protruded micro feature fabricated by reverse micro EDM (RMEDM). In the 1st stage, nano indentation was performed to experimentally determine the load-displacement plots, elastic modulus and hardness of the parent material, HAZ and the recast layer. In the 2nd stage, FEA simulation was carried out to mimic the nano indentation process and determine the load-displacement plots for all the three cases viz. parent material, recast layer and HAZ. Results demonstrated that the load'displacement plots obtained from numerical model in each case was in good agreement with that of the experimental curves. Based on simulated load-displacement plots, hardness was also calculated for parent material, HAZ and the recast layer. A maximum of 11% error was observed between simulated values of hardness and experimentally determined values.

Evaluating Mechanical Properties of Cement Materials by Depth-Sensing Indentation Method

2010 ◽  
Vol 44-47 ◽  
pp. 2587-2591
Author(s):  
Xiu Fang Wang ◽  
Yi Wang Bao ◽  
Kun Ming Li ◽  
Yan Qiu ◽  
Xiao Gen Liu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Engineering Application ◽  
Calculated Data ◽  
Absorption Capacity ◽  
Cement Industry ◽  
Depth Sensing ◽  
Indentation Method ◽  
Recovery Resistance

The energy consumption of crushing is directly affected by the mechanical properties of cement materials. The elastic modulus, energy dissipation, recovery resistance and other mechanical properties of cement materials are evaluated based on the depth-sensing indentation method in this work. It is significant and efficient for engineering application. In results, the calculated elastic modulus is close to that measured by dynamic method, being used to verify the correctness of the calculated data. And the calculated energy dissipation of clinker is higher than that of limestone and granite, which can partially be used to explain why the grinding of clinker consumes a lot of energy in cement industry. The recovery resistance of clinker is almost identical to that of granite, more than that of limestone. It is found that the clinker, in contrast to granite and limestone, exhibits better plasticity and greater energy absorption capacity.

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.

Mechanical Properties of Porous Si3N4 Ceramics

2013 ◽  
Vol 586 ◽  
pp. 166-169 ◽  
Author(s):  
Monika Kašiarová ◽  
Zuzana Vilčeková ◽  
Katarína Bodišová ◽  
Magdaléna Domanická ◽  
Miroslav Hnatko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Trabecular Bone ◽  
Porous Ceramics ◽  
Porous Si ◽  
Depth Sensing ◽  
Bone Material ◽  
Polyurethane Sponge

Mechanical properties of porous silicon nitride prepared by two different processing routes have been studied. Depth sensing methods was used to measure the hardness and elastic modulus of experimental materials. The results were compared with the hardness and elastic modulus of trabecular bone in order to find out porous ceramics with properties close to that of trabecular bone. Material prepared by infiltration of polyurethane sponge exhibited properties close to the properties of bone and it is the potential material for further investigation in the bioapplication field.

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