ASTM B430-97

1.1 This test method covers the determination of particle size distribution of refractory metal powders with a turbidimeter (1). Experience has shown that this test method is satisfactory for the analysis of elemental tungsten, molybdenum, rhenium, tantalum metal powders, and tungsten carbide powders. Other refractory metal powders, for example, elemental metals, carbides, and nitrides, may be analyzed using this test method with caution as to significance until actual satisfactory experience is developed. The procedure covers the determination of particle size distribution of the powder in two conditions:

1.1.1 As the powder is supplied (as-supplied), and

1.1.2 After the powder has been de-agglomerated by rod milling (laboratory milled) according to Practice B859.

1.2 Where dual units are given, inch-pound units are to be regarded as standard.

1.3 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 and health practices and determine the applicability of regulatory limitations prior to use.