| 摘要 |
<p>Residual elements including dissolved sorbed or occluded gases are sepd. from metal powders by placing the powder in a vacuum, heating to the m.pt. of the residual element, holding at temp. for a certain time (T1), heating to the b.pt. of the residual element, holding at temp. for a certain time (T2), and reducing the temp. of the powder to ambient temp. before recoving the powder from the vacuum. Alternatively, the heated powder may be cooled in a protective atmos. or may be cooled to a temp. which prevents moisture condensation prior to removal from the vacuum. The method gives high purity powders e.g. for use in the aircraft and aerospace industries.</p> |
