Measurement of hardness and elastic modulus by load and depth sensing indentation: Improvements to the technique based on continuous stiffness measurement

2021 ◽  
Author(s):  
P. Sudharshan Phani ◽  
W. C. Oliver ◽  
G. M. Pharr
Keyword(s):  
Elastic Modulus ◽  
Depth Sensing ◽  
Stiffness Measurement ◽  
Continuous Stiffness Measurement

Determination of elastic modulus and hardness of viscoelastic-plastic materials by instrumented indentation under harmonic load

2005 ◽  
Vol 20 (10) ◽  
pp. 2660-2669 ◽  
Author(s):  
J. Menčík ◽  
G. Rauchs ◽  
J. Bardon ◽  
A. Riche
Keyword(s):  
Elastic Modulus ◽  
Contact Stiffness ◽  
Harmonic Signal ◽  
Specific Response ◽  
Harmonic Load ◽  
Depth Sensing ◽  
Plastic Materials ◽  
Continuous Stiffness Measurement ◽  
Unloading Stiffness ◽  
Monotonic Load

When determining elastic modulus and hardness of viscoelastic-plastic materials by depth-sensing indentation, one must respect their specific response. In the monotonic load-unload testing mode, the unloading should be preceded by a dwell mitigating the influence of the delayed deforming. The continuous stiffness measurement (CSM) mode, with a small harmonic signal added to the basic monotonic load, enables continuous measurement of harmonic contact stiffness and mechanical properties as a function of depth. However, the contact depth and area in this mode actually depend on the slow (monotonic) component of the loading and should be determined not from the harmonic contact stiffness but from the unloading stiffness; otherwise, the calculated elastic modulus and mean contact pressure will be incorrect. This paper provides the formulae for these calculations, defines special characteristics—such as apparent dynamic hardness and the index of sensitivity to harmonic loading—and shows how to improve results by smoothing the harmonic stiffness curve. The proposed methods are illustrated through nanoindentation tests of polymethyl methacrylate.

scholarly journals Relationship of Stiffness-Based Indentation Properties Using Continuous-Stiffness-Measurement Method

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 97 ◽  
Author(s):  
Wai Yeong Huen ◽  
Hyuk Lee ◽  
Vanissorn Vimonsatit ◽  
Priyan Mendis
Keyword(s):  
Elastic Modulus ◽  
Measurement Method ◽  
Computational Simulation ◽  
Accurate Solution ◽  
New Approach ◽  
Stiffness Measurement ◽  
Pile Up ◽  
Continuous Stiffness Measurement ◽  
Relationship Of

The determination of elastic modulus (E) and hardness (H) relies on the accuracy of the contact area under the indenter tip, but this parameter cannot be explicitly measured during the nanoindentation process. This work presents a new approach that can derive the elastic modulus (E) and contact depth (hc) based on measured experiment stiffness using the continuous-stiffness-measurement (CSM) method. To achieve this, an inverse algorithm is proposed by incorporating a set of stiffness-based relationship functions that are derived from combining the dimensional analysis approach and computational simulation. This proposed solution considers both the sink-in and pile-up contact profiles; therefore, it provides a more accurate solution when compared to a conventional method that only considers the sink-in contact profile. While the proposed solution is sensitive to Poisson’s ratio (ν) and the equivalent indentation conical angle (θ), it is not affected by material plasticity, including yield strength (σy) and work hardening (n) for the investigated range of 0.001 < σy/E < 0.5. The proposed stiffness-based approach can be used to consistently derive elastic modulus and hardness by using stiffness and the load-and-unload curve measured by the continuous-stiffness-measurement (CSM) method.

Hardness and Elastic Modulus Measurements of AIN and TiN Sub-Micron Thin Films Using the Continuous Stiffness Measurement Technique with Fem Analysis

1999 ◽  
Vol 594 ◽  
Author(s):  
T. A. Rawdanowicz ◽  
J. Sankar ◽  
J. Narayan ◽  
V. Godbole
Keyword(s):  
Thin Films ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
Pulsed Laser ◽  
Fem Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stiffness Measurement ◽  
Tin Thin Films ◽  
Continuous Stiffness Measurement

AbstractThe hardnesses and elastic moduli of aluminum nitride (AIN) and titanium nitride (TiN) sub-micron thin films pulsed laser deposited (PLD) on silicon (111) were measured using nanoindentation based on a continuous stiffness measurement (CSM) technique. Thin film thicknesses, based on profile measurements of simultaneously grown step samples, are 210 nm and 180 nm with surface roughnesses of 12 nm and 2 nm for AlN and TiN, respectively. X-ray diffraction showed AlN as a highly textured polycrystalline AlN wurzite structure with a (0001) orientation and TiN as a cubic structure with a (111) orientation. The CSM technique provided hardness and elastic modulus as a function of depth. Finite element modeling (FEM) aided in determining the optimum indenter contact depth at which the thin films behaved as a semi-infinite solid with negligible substrate induced artifacts. Hardnesses of these AlN and TiN thin films were, determined analytically, 25 GPa and 33 GPa, as compared to FEM results of 24 GPa and 30 GPa, respectively. The elastic moduli measured 320 GPa and 370 GPa for these AlN and TiN thin films, respectively.

Characterization of Surface Layer of Silicon Wafer by Using Nano Indenter

2007 ◽  
Author(s):  
Yu-Li Sun ◽  
Dun-Wen Zuo ◽  
Yong-Wei Zhu ◽  
Feng Xu ◽  
Min Wang
Keyword(s):  
Elastic Modulus ◽  
Silicon Wafer ◽  
Bulk Material ◽  
Contact Stiffness ◽  
Indentation Test ◽  
Oxide Coating ◽  
Stiffness Measurement ◽  
Contact Depth ◽  
Continuous Stiffness Measurement

Mechanical properties of the silicon wafer are evaluated by a nano indenter system with the continuous stiffness measurement (CSM) technique. Contact stiffness, hardness and elastic modulus of the silicon wafer are continuously measured during the loading in an indentation test. The results show that when the contact depth is between 20 and 32 nm, its contact stiffness is linear with the contact depth, and its hardness and elastic modulus keep constant at 10.2 GPa and 140.3 GPa respectively, which belong to the oxide coating of the silicon wafer. When the contact depth is between 32 and 60 nm, its contact stiffness is not linear with the contact depth, and the hardness and elastic modulus increase rapidly with the contact depth, because they are affected by the bulk material. When the contact depth is over 60 nm, the contact stiffness of the silicon wafer is linear with the contact depth again, and the hardness and elastic modulus keep constant at 12.5 GPa and 165.6 GPa respectively, which belong to the silicon wafer, the bulk material.

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.

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.

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.

Time-dependent nanoindentation behavior of high elastic modulus dental resin composites

2010 ◽  
Vol 25 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Yijun Wang ◽  
Isabel K. Lloyd
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Resin Composite ◽  
Acrylic Resin ◽  
Resin Matrix ◽  
Resin Composites ◽  
Dental Resin ◽  
Elastic Plastic ◽  
High Elastic Modulus ◽  
Continuous Stiffness Measurement

Nanoindentation and the viscous-elastic–plastic (VEP) model developed by Oyen and Cook for lightly filled thermoplastic polymer composites were used to characterize the elastic modulus, hardness, and viscoelastic response of a new high elastic modulus dental resin composite. The VEP model was used because loading rate studies indicated a viscous component in the loading/unloading response of our highly filled, thermosetting acrylic resin composites. Increasing the volume fraction of our high modulus filler increased the elastic modulus and hardness and decreased the viscous response in our composites. Coupling the filler and resin matrix with a commercial coupling agent like Metaltite or MPTMS (3-methacryloxypropyltrimethoxysilane) that ionically bonds to the filler and covalently bonds to the matrix decreases the viscous response and increases the hardness of the composite. The coupling agents did not affect the elastic modulus. The ability of the VEP model to predict load–displacement trajectories and the correlation of the elastic modulus and hardness values determined from the VEP model with those from the direct continuous stiffness measurement mode nanoindentation measurements indicate that the VEP model can be extended to highly filled, thermosetting systems. This is valuable since the potential to predict elastic, plastic, and viscous contributions to behavior should be valuable in the design and understanding of future highly filled resin composite systems.

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