ISO 13947-2011 pdf free download

ISO 13947-2011 pdf free download.Metallic powders Test method for the determination of non-metallic inclusions in metal powders using a powder-forged specimen
Poudres metalliques — Determination de Ia teneur en inclusions non métalliques dans les poudres metalliques a I’aide d’une éprouvette forgée de poudre.
The maximum Feret’s diameter is used to determine inclusion size. A Ferets diameter is a caliper diameter, as illustrated in Figure 1.
The fragmented nature of some inclusions means that their size determination is somewhat complicated. The concept of near-neighbour separation shall be used in determining inclusion size. According to this concept, if an inclusion is within a certain distance of its neighbouring particles, it is considered a member of an inclusion cluster or agglomerate. Detected features within 30 pm of one another are considered part of the same inclusion. The concept is illustrated schematically in Figure 2.
The non-metallic inclusion level of the test specimen (part) is reported as the number of inclusions, per 100 mm2, greater than or equal to the predetermined size.
4 Significance and use
4.1 The non-metallic inclusion level of ferrous powders is an indication of powder cleanliness. In pressed and sintered ferrous powder metallurgy (PM) materials, the extensive porosity present masks the effect of inclusions on mechanical properties. In contrast, the properties of a PM material processed to near pore-free density are strongly influenced by the composition, size, size distribution, and location of non-metallic indusions.
4.2 The test for non-metallic inclusions in fully dense steel parts is useful as
— a characteristic to classify or differentiate one grade of powder or batch of parts from another, and
— a lot-to-lot quality comparison of powders intended for powder forging.
4.3 A significant amount of variation in non-metallic inclusion content will occur
— if the powder used to form the test specimen (part) does not meet the required quality standards for nonmetallic inclusion content, or
— processing of the test specimen (part) has been carried out under conditions that do not permit oxide reduction or allow oxidation of the test specimen (part), or both.
4.4 The use of the near-neighbour concept offers a more conservative estimate of the inclusions: it will overestimate rather than underestimate them.
5 Apparatus
5.1 Equipment, for the metallographic preparation of test specimens.ISO 13947-2011 pdf free download.