Graphite - Carbon - Carbide

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S-Bond Technologies offers joining services for components that require bonding to graphite, graphite foams, pyrolytic carbon, carbon foams, carbides and diamond. The active elements in S-Bond alloys and our proprietary joining processes enable us to join any metal and carbon based materials in a wide range of applications

Graphite and carbon require special processing to establish a chemical bond with their surfaces. Joining with S-Bond® alloys requires a special high temperature / vacuum metallization with a specially formulated S-Bond paste / suspension that is conducted at SBT or under a special license. After the treatment, the reaction of titanium in the S-Bond with the carbon base materials creates a metallurgical bond. The figures to the left show the cross section of (top) copper infiltrated carbon and (bottom) graphite foam (cell webs). The figures show the excellent interaction and infiltration of the S-Bond alloy that creates a chemically bonded structure. After this treatment, the graphite or carbon surfaces can be readily soldered using the S-Bond process at conventional soldering temperatures (200 – 280ºC), depending on the solder used in the joining. NOTE: Once the S-Bond metallization is complete, any solder filler may be used on the graphite/carbon surfaces, providing it is fluxless and uses mechanical agitation to disrupt the solders’ oxide surfaces during assembly.

Our joining techniques have the following characteristics:

• No flux.
• No filling of pores when joining foams.
• No pre-metallization required.
• Joins carbon based materials to most metals, ceramics and composites.
• Joints are made at lower soldering temperatures and can be reworked.
• S-Bond joining mitigates thermal expansion mismatch issues experienced in brazing.

S-Bond characteristics include:

• Alloy 220, which joins from 250-270°C.
• Alloy 400, which joins from 410-420°C.
• Thermally conductive, over 10 x that of filled epoxies

S-Bond Alloy 220 wets and adheres to the surface of the graphite and graphite foams, carbides, carbon and diamond. After a pre-treatment with S-Bond layers, the graphite / carbon / carbide based materials can be joined to electrical leads, metal face sheets or other types of metals and composite structures. When joining graphite foams, S-Bond alloys wet and encapsulate the Gr-foam webs, leading to adherence and gripping around the Gr-foam webs, thus creating strong and thermally conductive joints. S-Bond joining is an effective method for joining highly conductive graphite foams to metallic and composite face sheets.

S-Bond Technologies provides a range of versatile fabrication services to joining components such as:
 

• Graphite foam-core cold plates
• Graphite foam heat storage units
• Thermal management devices
• Diamond or diamond composite heat sinks
• SiC armor plates
• SiC based power electronic assemblies
• Wear plates and surfaces
• Graphite conductors and feedthru’s
   

Contact Us if you have any questions regarding your application(s).