Fabrication of Net Shape Parts

Because cold sintering uses rigid dies and achieves full density, parts with very close tolerances can be produced: <0.01 mm for a 10 mm opening (Ref 18). Thus the method can be used for the fabrication of parts with final shape and dimensions that do not need any additional machining. Elastic expansion after unloading (pressure release) should be taken into account. Wear resistant parts, tools, parts made of difficult to machine superalloys, stainless steels and titanium alloy, as well as parts made of metal glasses are of primary consideration. Examples of parts produced by cold sintering are shown in Fig. 18. Rectangular (3.2 by 10 by 40 mm) segments for stone-cutting tools were fabricated from metal-bonded (cobalt alloy or tool steel) diamond composites employing cold sintering followed by heat treatment at temperatures lower than the typical hot processing temperatures. Up to 28 segments could be produced in one pressure die, the processing cycle duration being 3 to 4 min. The performance of the cold sintered segments in field tests was better than that of similar segments manufactured by hot processing.

Fig. 18 Examples of parts produced by cold sintering

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