Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions

Mitra, I; Telle, R

doi:10.1006/jssc.1997.7311

Title: Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions

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Abstract

Numerous transition metal diborides of AlB{sub 2} structure type reveal large mutual solid solubility. Temperature-depending homogeneity ranges bordering immiscibility gaps within the system TiB{sub 2}-CrB{sub 2}-WB{sub 2} provide the opportunity to tailor an in situ grown typical platelet-shaped phase emerging from a supersaturated host matrix. Results are presented where variations in composition, manufacturing parameters, and heat treatment lead to precipitates of a {open_quotes}W{sub 2}B{sub 5}{close_quotes} structure accompanied by the formation of another tungsten boride less rich in boron in a (Ti, W, Cr)B{sub 2} matrix. All phases are characterized by high melting points and hardness. The enhanced formation of the matrix as well as the precipitation mechanism were activated by the addition of 6 to 20 mule% CrB{sub 2} to the system TiB{sub 2}-WB{sub 2}. Within the ternary solid solution, a particular composition range exists exhibiting a thermal expansion behavior similar to boron carbide. Attempts are made to toughen boron and silicon carbide ceramics by processing this in situ growth of platelets out of dispersed transition metal diboride within a carbide matrix.

Authors:

Mitra, I; Telle, R ^[1]

Institut fuer Gesteinshuettenkunde, Aachen (Germany)

Publication Date:: Wed Oct 01 00:00:00 EDT 1997

OSTI Identifier:: 569501

Resource Type:: Journal Article

Journal Name:: Journal of Solid State Chemistry

Additional Journal Information:: Journal Volume: 133; Journal Issue: 1; Other Information: PBD: Oct 1997

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; TITANIUM BORIDES; CHROMIUM BORIDES; TUNGSTEN BORIDES; HARDNESS; MELTING POINTS; PRECIPITATION; PROCESSING; SOLID SOLUTIONS; THERMAL EXPANSION; HEAT TREATMENTS

Citation Formats


                    Mitra, I, and Telle, R. Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions.  United States: N. p., 1997. 
        Web.  doi:10.1006/jssc.1997.7311.

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                    Mitra, I, & Telle, R. Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions.  United States.  https://doi.org/10.1006/jssc.1997.7311

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                    Mitra, I, and Telle, R. 1997.  
        "Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions".  United States.  https://doi.org/10.1006/jssc.1997.7311.

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@article{osti_569501,

  title        = {Phase formation during anneal of supersaturated TiB{sub 2}-CrB{sub 2}-WB{sub 2} solid solutions},

  author       = {Mitra, I and Telle, R},

  abstractNote = {Numerous transition metal diborides of AlB{sub 2} structure type reveal large mutual solid solubility. Temperature-depending homogeneity ranges bordering immiscibility gaps within the system TiB{sub 2}-CrB{sub 2}-WB{sub 2} provide the opportunity to tailor an in situ grown typical platelet-shaped phase emerging from a supersaturated host matrix. Results are presented where variations in composition, manufacturing parameters, and heat treatment lead to precipitates of a {open_quotes}W{sub 2}B{sub 5}{close_quotes} structure accompanied by the formation of another tungsten boride less rich in boron in a (Ti, W, Cr)B{sub 2} matrix. All phases are characterized by high melting points and hardness. The enhanced formation of the matrix as well as the precipitation mechanism were activated by the addition of 6 to 20 mule% CrB{sub 2} to the system TiB{sub 2}-WB{sub 2}. Within the ternary solid solution, a particular composition range exists exhibiting a thermal expansion behavior similar to boron carbide. Attempts are made to toughen boron and silicon carbide ceramics by processing this in situ growth of platelets out of dispersed transition metal diboride within a carbide matrix.},

  doi          = {10.1006/jssc.1997.7311},

  url          = {https://www.osti.gov/biblio/569501},
  journal      = {Journal of Solid State Chemistry},
number       = 1,

  volume       = 133,

  place        = {United States},

  year         = {Wed Oct 01 00:00:00 EDT 1997},

  month        = {Wed Oct 01 00:00:00 EDT 1997}

}

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