Mo2C intermediate layers for graphite–Cu system using the molten salt method

A simple and effective route for the direct synthesis of Mo2C coatings on graphite matrix is introduced for the joining of copper alloy heat sinks to graphite materials in Tokamak devices. The composition and microstructure of the Mo2C coatings on graphite, and the wetting behaviors of molten copper on coated and uncoated graphite were investigated. Results indicated that the Mo2C coatings were of several tens of micrometers depth in the graphite matrix. The coatings greatly improved the wettability of graphite by copper, and copper could be infiltrated into Mo2C-coated graphite matrix without external pressure. The strong interfacial bonding between copper and the graphite matrix was obtained by utilizing the mechanical interlocking within the space limitations of the graphite network. The Mo2C-modified graphite–copper samples resulted to have the average shear strength of 17 ± 4 MPa.

Mo2C-coated graphite matrix; copper infiltrated Mo2C-coated graphite matrix; variation in contact angle with time for the molten copper on graphite and Mo2C-coated graphite.Figure optionsDownload as PowerPoint slideHighlights
► Mo2C interlayer was prepared for graphite–Cu system by the molten salt method.
► The coatings improved the wettability of graphite by liquid copper greatly.
► Copper could be infiltrated into Mo2C-coated graphite matrix spontaneously.
► The graphite–copper samples have the average shear strength of 17 ± 4 MPa.