GB/T 21838.4-2020
Metallic materials—Instrumented indentation test for hardness and materials parameters—Part 4: Test method for metallic and non-metallic coatings (English Version)

Standard No.

GB/T 21838.4-2020

Language

Chinese, Available in English version

Release Date

2020

Published By

国家市场监督管理总局、中国国家标准化管理委员会

Latest

GB/T 21838.4-2020

Replace

GB/T 21838.4-2008

Scope

This document specifies instrumented indentation test methods for the hardness and material parameters of metallic and non-metallic coatings, which are particularly suitable for testing thin coatings in the nano/micro range. If the indentation depth is so small relative to the thickness of the covering layer that the influence of the matrix material can be ignored wherever possible and the covering layer can be treated as a bulk material, it is not necessary to adopt this document. The test limitations in this case will be given in this document. This method is limited to the test of a single layer of covering layer vertically indented on the specimen surface, but it can also be measured on its cross-section if the thickness or gradient of each layer is greater than the measurement resolution relative to the indentation size. Available in gradient and multi-layer overlay material properties. This method is not limited to the type of material, it is applicable to metallic and non-metallic coatings. In this document, the term "covering layer" is used to describe any solid layer that differs from the bonding matrix and has homogeneous properties. This method assumes that the overburden properties do not vary with indentation depth. For composite covers, if the microstructure size is smaller than the indentation size, the composite cover can be considered homogeneous. This document applies only to the use of pyramidal or conical indenters with a sufficiently small radius of curvature at the top to ensure that the plastic deformation produced by the measurement occurs inside the coating. For viscoelastic or creep-prone materials, the test time has a great influence on the hardness measurement. Note 1: ISO14577 1, ISO14577 2 and I.

GB/T 21838.4-2020 Referenced Document

• GB/T 21838.1-2019 Metallic materials—Instrumented indentation test for hardness and materials parameters—Part 1:Test method
• ISO 14577-2:2015 Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 2: Verification and calibration of testing machines

GB/T 21838.4-2020 history

• 2020 GB/T 21838.4-2020 Metallic materials—Instrumented indentation test for hardness and materials parameters—Part 4: Test method for metallic and non-metallic coatings
• 2008 GB/T 21838.4-2008 Metallic materials.Instrumented indentation test for hardness and materials Parameters.Part 4:Test method for metallic and non-metallic coatings

GB/T 21838.4-2020 -All Parts