Effect of grain orientation on the compressive response of highly oriented MAX phase Ti3SiC2

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:809

Article

Zhao, Xingyuan¹  Sokol, Maxim²  Barsoum, Michel W.²  Lamberson, Leslie¹ 

[1] Colorado Sch Mines, Dept Mech Engn, Golden, CO 80401 USA

[2] Drexel Univ, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA

关键词: MAX phase;    Compression;    Titanium silicon carbide;    Highly oriented;    Rate sensitivity;   

DOI  :  10.1016/j.msea.2021.140869

来源: Elsevier

【 摘 要 】

The MAX phases comprise of a group of layered ternary carbides that exhibit unique mechanical properties which bridge the gap between their metal and ceramic constituents. To study the effects of the global grain orientation, Ti, Si and TiC powders were hot pressed to synthesize highly oriented bulk Ti3SiC2. X-ray diffraction (XRD) was used to verify the grain orientation and a Lotgering factor of 0.87 with respect to the c-axis was obtained. Prepared Ti3SiC2 samples have been compressed in two orientations, loading along the c-axis (parallel to c-axis) and perpendicular to the c-axis (perpendicular to c-axis) at 10(-3) s(-1) using a standard load frame and at 10(2) s(-1) using a Kolsky (split-Hopkinson) bar. The average compressive strength along the perpendicular to c-axis orientation was 761 MPa under quasistatic conditions and 987 MPa under dynamic loading, exhibiting a 30% increase on average. The parallel to c-axis orientation exhibited no rate dependence in compressive strength; however both orientations exhibited an increase of strain at failure under dynamic conditions by over 0.5%, on average. The orientation-dependent failure behavior at different strain rates were examined using high-speed imaging and 2D digital image correlation (DIC) during loading and via scanning electron microscopy (SEM) post-mortem. Results indicate that the perpendicular to c-axis fracture surface exhibited a mixture of transgranular and intergranular cracks, kink bands and delaminations, whereas parallel to c-axis was limited to a combination of intergranular and transgranular cracks. Such fracture distinctions due to the availability (or lack thereof) for kink band formation appear to be responsible for the anisotropic compressive behavior.

【 授权许可】

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