GB/T 9790-2021 Active

This document specifies the principles, symbols, and explanations of the Vickers and Knoop microhardness tests for metals and other inorganic coatings, as well as the equipment, factors affecting measurement accuracy, test procedures, uncertainty of results, and test reports.
This document is applicable to the determination of various coatings, such as electrodeposition coatings, autocatalytic coatings, spray-applied aluminum coatings, and aluminum anodic oxide films. During the determination, the test force is generally not greater than 9.807 N (1 kgf). Section 8.3 of this document is applicable to the determination of microhardness in the cross-section of coatings, and Section 8.4 is applicable to the determination of microhardness on the surface of coatings.
Note 1: Parts 1 to 4 of GB/T 18449 describe the Knoop hardness test for metal materials. Parts 1 to 4 of GB/T 4340 describe the Vickers hardness test for metal materials. Parts of GB/T 21838 (all parts) describe the instrumented indentation test for metal material hardness and material parameters.
Note 2: The test force for coatings is usually selected within the Vickers hardness range specified in GB/T 4340.1-2009. However, since it is advisable to select a large test force whenever possible, a test force within the small Vickers hardness range specified in GB/T 4340.1-2009 can also be selected.