ISO 14577-1-2015 pdf free.Metallic materials — Instrumented indentation test for hardness and materials parameters — Part 1: Test method.
This part of Iso 14577 specifies the method of instrumented indentation test for determination of
hardness and other materials parameters for the following three ranges:
— macrorange:2NsFs3OkN;
— micro range: 2 N> F; h > 0.2 tm;
— nano range: h 0,2 pm.
For the nano range, the mechanical deformation strongly depends on the real shape of indenter tip and the calculated material parameters are significantly influenced by the contact area function of the indenter used in the testing machine. Therefore, careful calibration of both instrument and indenter shape is required in order to achieve an acceptable reproducibility of the materials parameters determined with different machines.
The macro and micro ranges are distinguished by the test forces in relation to the indentation depth.
Attention is drawn to the fact that the micro range has an upper limit given by the test force (2 N) and a lower limit given by the indentation depth of 0,2 pm.
The determination of hardness and other material parameters is given in AnnexA.
At high contact pressures, damage to the indenter is possible. For this reason in the macro range. hardmetal indenters are often used. For test pieces with very high hardness and modulus of elasticity. permanent indenter deformation can occur and can be detected using suitable reference materials. It is necessary that its influence on the test result be taken into account.
This test method can also be applied to thin metallic and non-metallic coatings and non-metallic materials. In this case, it is recommended that the specifications in the relevant standards be taken into account (see also 3 and ISO 14577-4).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 14577-2:2015, Metallic materials — instrumented indentation test for hardness and materials parameters — Part 2: Verification and calibration of testing machines
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)
4 Principle
Continuous recording of the force and the depth of indentation permits the determination of hardness and material properties (see Figure 1 and Figure 2). An indenter consisting of a material harder than the material under test shall be used. The following shapes and materials can be used:
a) diamond indenter shaped as an orthogonal pyramid with a square base and with an angle a = 68° between the axis of the diamond pyramid and one of the faces (Vickers pyramid; see FigureAJ);
b) diamond pyramid with triangular base (e.g. modified Berkovich pyramid with an angle a = 65,27°
between the axis of the diamond pyramid and one of the faces; see Figure A.1) c) hardrnetal ball (especially for the determination of the elastic behaviour of materials); d) diamond spherical tipped conical indenter.
This part of ISO 14577 does not preclude the use of other indenter geometries; however, care should be taken in interpreting the results obtained with such indenters. Other materials like sapphire can also be used.
NOTE Due to the crystal structure of diamond, indenters that are intended to be spherical are often polyhedrons and do not have an ideal spherical shape.
The test procedure can either be force-controlled or displacement-controlled. The test force, F, the corresponding indentation depth, h. and time are recorded during the whole test procedure. The result of the test is the data set of the test force and the relevant indentation depths as a function of time (see Figure 1 and Annex B).
For a reproducible determination of the force and corresponding indentation depth, the zero point for
the force/indentation depth measurement shall be assigned individually for each test (see Z3). Where time-dependent effects are being measured
— using the force-controlled method, the test force is kept constant over a specified period and the change of the indentation depth is measured as a function of the holding time of the test force (see Figures A.3 and Ba). and
— using the indentation depth controlled method, the indentation depth is kept constant over a specified period and the change of the test force is measured as a function of the holding time of the indentation depth (see Figures A.4 and 11.2).
The two kinds of control mentioned give essentially different results in the segment b of the curves in Figure B.1 a) and Figure B.2 b) or in Figure B.1 b) and Figure B.2 a).ISO 14577-1 pdf free download.