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HomeMaterials Science ForumMaterials Science Forum Vols. 747-748Room Temperature Brittlement of T2 in the Mo-Si-B...

Room Temperature Brittlement of T2 in the Mo-Si-B System

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Abstract:

Compression and three-point bending tests were conducted at room temperature (RM) on the Mo₅SiB₂ (T2) alloy, which was prepared by sparking plasma sintering (SPS). It was found that almost no plastic deformation occured in the T2 alloy before failure but with a tremendous compressive strength of 2907 MPa. The fracture toughness determined from the single edge notch bend specimen is 3.34 MPa·m^1/2, similar to the value of 3.5 MPa·m^1/2 in ɑ-Al₂O₃. Once the cleavage crack initiated near the notch under continuous loads, it propagated on a certain plane (001) until the specimen completely fractured. In this work, the electronic structure was also calculated by the first-principles method, indicating that the contribution to RM brittleness is mainly caused by the covalent bonds which arrange alternately in the T2 phase.

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Periodical:

Materials Science Forum (Volumes 747-748)

Pages:

132-138

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.747-748.132

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Online since:

February 2013

Authors:

Kun Ming Pan, Lai Qi Zhang, Wei Du, Jun Pin Lin

Keywords:

Covalent Bond, First-Principles Calculation, Intrinsic Brittlement, T2

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