Determination of Time-Dependent Plastic Properties of Metals by Indentation Load Relaxation Techniques

1984 ◽  
Vol 40 ◽  
Author(s):  
Simo-Pekka Hannula ◽  
Donald Stone ◽  
Che-Yu Li
Keyword(s):  
Thin Film ◽  
Indentation Test ◽  
Indentation Load ◽  
Time Dependent ◽  
Relaxation Techniques ◽  
Load Relaxation ◽  
Surface Layers ◽  
Plastic Properties ◽  
Load Relaxation Test

AbstractLoad relaxation testing has been demonstrated to be useful for characterizing the time dependent plastic properties of metals. However, for testing of small material volumes, such as thin film metallizations, thin films, and contact surfaces, conventional load relaxation techniques cannot be used. For such applications an indentation test offers an attractive means for obtaining data necessary for materials characterization. This work shows that an indentation load relaxation test is experimentally feasible for thin film testing. Experiments on brass and beryllium copper samples with or without a gold/nickel plating illustrate different relaxation properties of the substrates and the surface layers. Furthermore, results of experiments on some fcc metals suggest rather simple relations between the conventional uniaxial load relaxation (LR) test and the indentation load relaxation (ILR) test.

Determination of the Elastic-Plastic Properties of 15Kh2MFA Steel with Austenitic Cladding

2013 ◽  
Vol 586 ◽  
pp. 43-46 ◽  
Author(s):  
Aleš Materna ◽  
Jiri Nohava ◽  
Petr Haušild ◽  
Vladislav Oliva
Keyword(s):  
Tensile Test ◽  
Indentation Test ◽  
Strain Curve ◽  
Indentation Load ◽  
Spherical Indentation ◽  
Compression Tests ◽  
Material Interface ◽  
Plastic Properties ◽  
Longitudinal Orientation ◽  
Sufficient Distance

The spherical indentation response of pressure vessel reactor steel with austenitic cladding is investigated both experimentally and numerically. The instrumented indentation test was performed for both materials at a sufficient distance from the bi-material interface, thus the results can be compared with the bulk data obtained from the standard tensile and compression tests. The stress – plastic strain curve for austenitic cladding estimated by a simplified inverse analysis of the indentation load – penetration curve is shifted to a harder response compared with that determined from the tensile test. One of the possible reasons, anisotropy of the cladding metal, was experimentally observed during the compression tests performed in the longitudinal orientation of the tensile test specimens and in the transverse orientation identical with the direction of the material indentation.

Indentation Load Relaxation Studies of Thin Film-Substrate Systems

1986 ◽  
Vol 72 ◽  
Author(s):  
D. Stone ◽  
W. Lafontaine ◽  
S. Ruoff ◽  
S.-P. Hannula ◽  
B. Yost ◽  
...  
Keyword(s):  
Thin Film ◽  
Aluminum Film ◽  
Indentation Load ◽  
Load Relaxation ◽  
Tin Film ◽  
Relaxation Studies ◽  
Film Substrate

AbstractResults from indentation load relaxation (ILR) tests on thin film-substrate systems are reported. In the case of a 1 pum aluminum film on silicon, the data can be interpreted as reflecting both the properties of the film and the interface between film and substrate. Data from a 37μm TiN film on 304 SS are believed to reflect the combined behavior of the film and substrate.

Instrumented Indentation Test

2011 ◽  
pp. 167-233
Author(s):  
C. Ullner
Keyword(s):  
Indentation Test ◽  
Indentation Load ◽  
True Stress ◽  
Test Method ◽  
Indentation Hardness ◽  
Instrumented Indentation ◽  
Hardness Testing ◽  
Scope Of Application ◽  
Instrumented Indentation Test

Abstract Instrumented indentation hardness testing significantly expands on the capabilities of traditional hardness testing. It employs high-resolution instrumentation to continuously control and monitor the loads and displacements of an indenter as it is driven into and withdrawn from a material. The scope of application comprises displacements even smaller than 200 nm (nano range) and forces even up to 30 kN . Mechanical properties are derived from the indentation load-displacement data obtained in simple tests. The chapter presents the elements of contact mechanics that are important for the application of the instrumented indentation test. The test method according to the international standard (ISO 14577) is discussed, and this information is supplemented by information about the testing technique and some example applications. The chapter concludes with a discussion on the extensions of the standard that are expected in the future (estimation of the measurement uncertainty and procedures for the determination of true stress-strain curves).

Study of Delamination of Thin Film Coating on Cyclic Nano-Indentation Test

2007 ◽  
Vol 353-358 ◽  
pp. 1842-1845 ◽  
Author(s):  
Kentaro Kozuki ◽  
Masaki Omiya ◽  
Kikuo Kishimoto ◽  
Hirotsugu Inoue
Keyword(s):  
Thin Film ◽  
Evaluation Method ◽  
Surface Profile ◽  
Indentation Test ◽  
Interfacial Strength ◽  
Peel Test ◽  
Indentation Load ◽  
Displacement Curve ◽  
Buckling Mode ◽  
Nano Indentation

The aim of this paper is to evaluate the cyclic interfacial strength between thin film and its substrate by cyclic nano-indentation tests. The specimen used in this study is PET substrate/ITO coatings layered specimen. From the indentation load and displacement curve, we proposed an evaluation method for the interfacial strength. The results are good agreement with the interfacial strength evaluated by peel test. After cyclic indentations, the surface profile was observed by atomic force microscope. The number of elongates increased with indentation cycles when the indentation load is low, whereas elongates number is almost constant under high load cases. These phenomena can be explained by simple models. In this study, two types of fracture modes are proposed. They are “subsidiary fracture mode” and “buckling mode”.

Indentation Load Relaxation Experiments on Al-Si Metallizations

1990 ◽  
Vol 188 ◽  
Author(s):  
W. R. LaFontaine ◽  
B. Yost ◽  
R. D. Black ◽  
Che-Yu Li
Keyword(s):  
Flow Behavior ◽  
Indentation Load ◽  
Load Relaxation ◽  
Depth Of Penetration ◽  
Flow Curves ◽  
Bulk Specimen ◽  
Load Relaxation Test ◽  
Relaxation Experiments ◽  
Film Substrate ◽  
Penetration Depths

ABSTRACTIndentation load relaxation (ILR) experiments with indentation depths in the submicron range are described. The observed flow behavior of a 1μm thick A1-2%Si film deposited on a silicon substrate depended on the depth of penetration. For shallow penetration depths, the shape of the flow curves obtained from this sample are similar to those obtained from a conventional load relaxation test of a bulk specimen. For penetration depths close to the film/substrate interface, the influence of the substrate on the film's deformation behavior was observed.

scholarly journals Exploitation of Nanoindentation and Statistical Tools to Investigate the Behavior of Materials

2016 ◽  
Vol 6 (4) ◽  
pp. 1089-1092
Author(s):  
L. Aminallah ◽  
S. Habibi
Keyword(s):  
Polynomial Regression ◽  
Contact Stiffness ◽  
Characteristic Curve ◽  
Indentation Test ◽  
Statistical Processing ◽  
Indentation Load ◽  
Contact Depth ◽  
Characterization Of Materials

The determination of the performance of materials requires the characterization of materials at scales: macro, micro and nanoscale. Among the most common experimental methods one can find the instrumented indentation test for determining the contact stiffness and contact depth and analyzing the characteristic curve by nanoindentation load on the penetration of the indentor. Through statistical processing of the experimental results, the rigidity of contact on the contact depth is investigated, depending on the indentation load, for bronze, brass and copper. A mathematical model is adopted to describe the polynomial regression by the method of least squares growth rigidity with one or more geometric parameters representative of the size of the footprint. This study allows us to identify factors that influence the rigidity of the materials examined and the sensitivity of the used indenters.

Microscratch and load relaxation tests for ultra-thin films

1991 ◽  
Vol 6 (2) ◽  
pp. 407-426 ◽  
Author(s):  
T.W. Wu
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Normal Load ◽  
Fatigue Tests ◽  
Plastic Strain Rate ◽  
Relaxation Techniques ◽  
Load Relaxation ◽  
Tangential Load ◽  
Creep Properties ◽  
Load Relaxation Test

The microindenter has proven to be a powerful device in the characterization of the mechanical properties of thin films. The machine has both high resolution in the applied load and penetration depth measurements, as well as the versatility to perform different types of testing. The former provides the capability to deal with extremely thin films, while the latter allows for other mechanical properties, in addition to hardness, to be acquired. Four types of tests, namely indentation, scratch, load relaxation, and indentation fatigue tests can currently be conducted using the microindenter via different operating procedures. Only the scratch and load relaxation techniques will be covered in this paper. In a microscratch test, the normal load, tangential load, scratch length, and acoustic emission are monitored simultaneously during an entire scratch process for the purposes of measuring the critical load and studying the failure mechanisms of the deposited films. The adhesion strength, scratch hardness, fracture toughness, and friction are the mechanical properties which are possible to obtain by using this technique. Results from aluminum, carbon, and zirconia coatings will be discussed. The load relaxation test provides information on the creep properties of the films and results in an empirical constitutive relation between the applied stress and plastic strain rate. The creep properties of DC sputtered Al films will be used as an illustration of this.

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