| 摘要 |
A plasma heating apparatus (20) for heating a workpiece (26) includes a chamber (22) of sufficient size to receive a workpiece (26) therein and a source of a reduced gas pressure within the chamber (22) of from about 0.01 to about 100 millitorr. The plasma heating apparatus (20) further includes a plasma source (40) of an enveloping plasma. Optionally, a workpiece voltage may be applied between the workpiece (26) and the wall (24) of the chamber (22), a source (34) of a reactive gas can be provided to backfill the chamber (22), and radiant heaters (25) can be provided to independently heat portions of the workpiece (26). In operation, the plasma source (40) produces a plasma that surrounds and heats the workpiece (26). The plasma and the heating of the workpiece (26) are tailored to achieve controllably uniform or nonuniform heat treatment and/or surface treatment of the workpiece (26). The apparatus (20) can be used to heat treat the workpiece (26) in vacuum, or a reactive gas such as a gaseous source of nitrogen, carbon, or boron can be backfilled into the chamber (22) to alter the surface chemistry of the workpiece (26).
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