1.1 This International Standard specifies methods of hardness testing of sintered metal materials, excluding hardmetals.
1.2 Procedure 1 determines the apparent hardness of the whole material.
- applies to sintered metal materials which have either not been subjected to any heat treatment, or which have been heat treated in such a way that the hardness is essentially uniform to a depth of at least 5 mm below the surface,
- applies to the surfaces of sintered metal materials which have been treated in such a way that the hardness is not uniform in the section to a depth of 5 mm below the surface,
- therefore applies to materials in which the hardness is obtained essentially by surface enrichment by carbon, or by carbon and nitrogen (for example by carburizing, carbonitriding, nitrocarburizing or sulfidizing), and
- applies to materials which have been induction hardened.
1.3 Procedure 2 determines the microhardness of the metal phase.
- applies to all types of sintered metal materials,
- is used, in particular, to determine the hardness profile of case-hardened or carbonitrided materials in accordance with the method described in ISO 4507, and
- also applies to any sintered metallic materials which have been subjected to surface treatments such as electrodeposited plating, chemical coating, chemical vapour deposition (CVD), physical vapour deposition (PVD), laser, ion bombardment, etc. To determine the microhardness of treated surfaces, Procedure 2 applies.
NOTE However, an international agreement has not yet been reached on a number of factors involved in microhardness testing. Nevertheless, the parameters defined in Procedure 2 are important enough to enable a considerable measure of standardization of extensively used practices.