ASTM E159-22

SIGNIFICANCE AND USE 5.1 The oxygen content of a powder affects both its green and sintered properties. 5.2 Hydrogen loss is a term widely used in the powder metallurgy industry even though the measurement represents an approximate oxygen content of the powder. 5.3 Oxygen is the most common hydrogen-reducible constituent of metal powders, and this procedure may be used as a measure of oxygen, reducible under the test conditions, if other interfering elements are absent. SCOPE 1.1 This test method covers the determination of the mass of hydrogen-reducible constituents in the following metal powders: cobalt, copper, iron, and tungsten. 1.2 This test method is useful for cobalt, copper, and iron powders in the range from 0.05 to 3.0 % oxygen, and for tungsten powder in the range from 0.01 to 0.50 % oxygen. 1.3 This test method does not measure the oxygen contained in oxides such as silicon oxide (SiO2), aluminum oxide (Al2O3), magnesium oxide (MgO), calcium oxide (CaO), titanium dioxide (TiO2), etc. that are not reduced by hydrogen at the test temperatures. 1.4 For total oxygen content, vacuum or inert gas fusion methods are available (see Test Methods E1019). 1.5 Untis—The values stated in SI units are to be regarded as the standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.