A Simple and Direct Tungsten Brush Fabrication Technique

50864-98-I A Simple and Direct Tungsten Brush Fabrication Technique--Surmet Corporation, 33 B Street, Burlington, MA 01803-3406; (781) 272-3250 Dr. Nilesh Gunda, Principal Investigator Dr. Suri A. Sastri, Business Official DOE Grant No. DE-FG02-98ER82680 Amount: $75,000 Reliable technology for bonding plasma facing armor to the copper cooling structure is critical to the successful design and construction of a future fusion reactor. Since joint failure can lead to run away conditions with serious consequences, the reliability of joints in fusion reactors must be guaranteed. This requires innovative engineering design concepts to reduce the stress in the joints. Brush structures are desirable because stress singularities are virtually eliminated. The brush concept reduces not only the thermal strain mismatch but also avoids the stress singularity found at the edge of the interface. This project will develop an innovative processing method that will allow rapid fabrication of a novel tungsten brush structure. In Phase I, the brush structure will be fabricated from tungsten rods and a high thermal conductivity, high strength copper alloy, using an energy efficient approach. The fabricated brush will be subjected to thermal cycling and other tests. Commercial Applications and Other Benefits as described by the awardee: The ability to successfully fabricate a brush structure by utilizing a low energy method to bond copper alloy with a bundle of refractory metal rods, such as tungsten, should be commercially applicable to the bonding of other dissimilar materials. _