Rubber, vulcanized or thermoplastic. Determination of indentation hardness

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instrumentation to continuously control and monitor the loads and displacements of an indenter as it is driven into and withdrawn from a material.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).

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Extended characterization of materials based on continuous instrumented indentation diagrams

Uspihi materialoznavstva ◽

10.15407/materials2021.03.013 ◽

2021 ◽

Vol 2021 (3) ◽

pp. 10-23

Author(s):

B. A. Galanov ◽

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S. M. Ivanov ◽

V. V. Kartuzov ◽

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...

Keyword(s):

Material Flow ◽

Elastic Moduli ◽

Contact Stiffness ◽

Relative Size ◽

Indentation Hardness ◽

Instrumented Indentation ◽

Characterization Of Materials ◽

Instrumental Indentation

In addition to the traditional determination of hardness and elastic moduli from continuous diagrams of instrumental indentation, it is proposed to determine the yield stress, the characteristic of plasticity, the characteristic relative size of the elastoplastic zone under the indenter, and the volumetric deformation of the material in the area of contact of the indenter with the sample. The indentation diagram shows the transition point to the unconstrained material flow under the indenter. Keywords: indentation, hardness, elastic moduli, contact stiffness, elastic-plastic strains.

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