Active Standard ASTM B311 | Developed by Subcommittee: B09.11
Book of Standards Volume: 02.05
Historical (view previous versions of standard)
Significance and Use
5.1 For PM materials containing less than two percent porosity, a density measurement may be used to determine if the part has been densified, either overall or in a critical region, to the degree required for the intended application. Density alone cannot be used for evaluating the degree of densification because chemical composition and heat treatment affect the pore-free density.
5.2 For cemented carbides, a density measurement is normally used to determine if there is any significant deviation in composition of the carbide grade. For straight tungsten carbide-cobalt grades, the relationship is straightforward. For complex carbide grades (for example, grades containing tantalum carbide or titanium carbide, or both, in addition to tungsten carbide-cobalt), the situation is more complicated. If the measured density is beyond the specified limits, the composition is outside of the specified limits. A measured density within the specified limits does not ensure correct composition; compensation between two or more constituents could result in the expected density with the wrong composition. Density alone cannot be used for evaluating a cemented carbide grade.
1.1 This test method covers the determination of density for powder metallurgy (PM) materials containing less than two percent porosity and for cemented carbides. This test method is based on the water displacement method.
1.2 With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubic centimeter (g/cm3) and gram (g) units is the long-standing industry practice, the values in SI units are to be regarded as standard.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
B243 Terminology of Powder Metallurgy
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
ICS Number Code 77.160 (Powder metallurgy)
UNSPSC Code 31133703(Cemented carbide powdered metal and metal alloy)