Elmet Technologies

Tungsten Pressed & Sintered Parts

Among the characteristics which make tungsten and molybdenum useful metals are their high melting points, along with high tensile properties and hardness. These same properties also make it difficult for simple and economic production of powder metallurgy parts. Elmet has successfully developed the powder metallurgy process for the commercial production of molybdenum and tungsten semiconductory heat sinks. They are now being supplied to customers around the world at a rate of billions of parts a year.

This technology also lends itself to the production of other high volume, discrete parts with simple geometries. Listed below are some the parameters to be considered in evaluating such sintered metal products for practical commercial production.

Materials
Molybdenum and tungsten only. Elmet has unique capabilities for these two materials. There is also the possibility of alloying molybdenum and tungsten.

Shapes
Simple shapes are: cylinders, discs, cubes, washers and spheres. In general, symmetrical shapes are most easily produced.

Size Considerations
Maximum Overall Envelope	.250" x .250" x .250"
Optimum Length to Width (Diameter/Thickness)	1:1
Greatest Length to Width	13:1

For Discs or Squares
Maximum Diameter/Width	.250"
Minimum Thickness	10% of Diameter or Width
Minimum Diameter/Width	.030"
Minimum Thickness	10% of Diameter or Width

Tolerances
Semiconductory heat sinks	± .002" on Length	±.001" on Diameter

Density
Molybdenum and Tungsten	94% Minimum	96% Typical