Tungsten Composites

Thermkon® Copper Tungsten and Copper Molybdenum
Elkonite® Copper Tungsten

Thermkon® Copper Tungsten and Copper Molybdenum

Thermkon® is a registered trademark of CMW Inc. Thermkon® materials are tungsten composites, engineered to provide controlled coefficients of thermal expansion and have high strength and thermal conductivity. They are joined with ceramics or other semi-conductors used on the electronics industry (thus, they are excellent bases, heat sinks and structural members for integrated circuits semi-conductors and high power electron tubes.)

Properties
Machining Guidelines
MSDS Sheets

Availability & Types:
Thermkon® tungsten composites are pressed into near net shape and sintered, not rolled into a sheet like other materials used as heat sinks. Typical sizes are 1" or 2" square x .25" thickness (or something similar). We normally manufacture a blank and the customer machines that blank into the specific dimension for the required part.

CMW currently produces six standard grades of Thermkon®, each with its own CTE (coefficient of thermal expansion). These, together with their measured nominal (20 °C) CTE values are listed below by increasing CTE:

Thermkon® 62 (6.1 ppm / °C at 20 °C)
Thermkon® 65M (6.5 ppm / °C at 20 °C)
Thermkon® 68 (6.7 ppm / °C at 20 °C)
Thermkon® 70M (7.2 ppm / °C at 20 °C)
Thermkon® 76 (7.6 ppm / °C at 20 °C)
Thermkon® 83 (8.5 ppm / °C at 20 °C)

Thermkon® tungsten composites can be engineered and produced with other nearby expansion values by altering the ratio of refractory to copper content when required.

Thermkon® materials are made by sintering pure refractory metal (either tungsten or molybdenum) to a controlled amount of interconnected porosity. This sintered "refractory sponge" is then infiltrated with molten copper, to create a bimetal composite which has the highest density and purity possible, ensuring MAXIMUM THERMAL CONDUCTIVITY for the specific ratio of combined metals.

Maximum control of properties is obtained when discrete parts are pressed in automated equipment. Size limitations for such pressing are:

0.080" [2 mm] minimum thickness
2.250" [5.7 cm] maximum plan dimension
0.375" [9.5 mm] minimum plan dimension
Parts thinner than 0.080" are manufactured by grinding and lapping from 0.080" which adds considerable cost. Parts of larger dimensions, and "bars" are also produced; but "manual" pressing is used, which roughly doubles the variability of the CTE and thermal conductivity from piece to piece.

Solder attachment to devices and substrates is facilitated by available gold plating which exceeds MIL-G-45204C for purity, thickness, hardness, and ease of soldering and brazing.

Elkonite® Copper Tungsten

Elkonite® is a registered trademark of CMW Inc. Elkonite® tungsten copper materials typically range from 50% to 90% tungsten with the balance made of copper. These materials are chosen to solve unique challenges in a variety of applications ranging from EDM/ECM electrodes, weight and nozzle applications to gyroscope and inertial guidance systems.

Elkonite® Copper Tungsten

Elkonite® 40W3 and Elkonite® 50W3 have the highest tungsten content. Because of their very high density, excellent machinability, and totally non-magnetic nature Elkonite® 40W3 and Elkonite® 50W3 are often chosen for weights and high inertia components. Additionally, their great high temperature strength and cooling effect by copper evaporation have permitted their use in a variety of rocket nozzle and rocket vane applications involving hot gas erosion.

Properties
Machining Guidelines
Welding & Joining Guidelines
MSDS Sheets