Sinterbonding Cobalt-Cemented Tungsten Carbide to Tungsten Heavy Alloys
Cobalt-cemented tungsten carbide (WC-Co) powder was sinterbonded to nickel-iron tungsten heavy alloy (WHA) for use in high-temperature tooling applications. Sinterbonding was performed under various conditions, including changes to the sintering conditions and initial WHA material forms, to determine various processing conditions that yield a consolidated interface indicative of a high degree of bonding. Sinterbonding WC-Co to fully dense WHA bar stock yielded a consolidated interface comprised primarily of complex η-carbides. Defects at the interface, including voids, microcracking, and porosity were the result of other sinterbonding processing conditions explored in this work. Co-rich η-carbides were found to form at the interface in every condition examined. A thermodynamic evaluation of η-carbides as a function of carbon activity determined that Co-rich η-carbides formed preferentially in regions of low carbon activity. The predicted thermodynamic trends are in agreement with interfacial microstructural observations.
J. M. Rodelas et al., "Sinterbonding Cobalt-Cemented Tungsten Carbide to Tungsten Heavy Alloys," International Journal of Refractory Metals and Hard Materials, Elsevier, Sep 2009.
The definitive version is available at http://dx.doi.org/10.1016/j.ijrmhm.2009.03.001
Materials Science and Engineering
Missouri University of Science and Technology. Intelligent Systems Center
Keywords and Phrases
Friction Stir Welding Tools; Sinterbonding; Tungsten Carbide; Tungsten Heavy Alloy; Η-Carbide
Article - Journal
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