Dynamic compressive response of zirconium diboride‐silicon carbide composites at high‐strain rates

Abstract

The quasi-static, dynamic compression experiments and micromechanical model were employed to declare the dynamic compressive response of ZrB 2 -20%SiC composite at high-strain rates. The quasi-static compressive strengths were measured to determine the range of initial microcrack length in ZrB 2 -20%SiC composite. The effects of the strain rate on dynamic compressive strength, critical stain, as well as fracture mechanisms were discussed based on experimental results. Dynamic mechanical properties of ZrB 2 -based composites display obvious strain rate dependence. The dynamic increase factor in the compressive strength shows a rapid increase above a transition strain rate of 1228 s −1 . Moreover, a micromechanical model considering initial microcrack lengths is used to predict dynamic compressive strengths, which agree with the experimental results. Additionally, the critical strain has a linear increase tendency with the increase of strain rate. The dynamic compressive fracture mechanism of ZrB 2 -20%SiC composite is relative to the combination effect between strain rate and microstructure. The size of flaw distribution is critical below the transition strain rate resulting in bigger fragments, whereas the flaw density is primary with more and smaller fragments above the transition strain rate. K E Y W O R D Sdynamic compressive strength, fracture mechanism, micromechanical model, strain rate, ZrB 2 -20%SiC composite How to cite this article: Wang M, Kong D, Wang L, Li Y, Cai T. Dynamic compressive response of zirconium diboride-silicon carbide composites at highstrain rates. Int J Appl Ceram Technol. 2019;16:2206-2213. https ://doi.

Dynamic tensile mechanical properties and failure mode of zirconium diboride‐silicon carbide ceramic composites

“…Dynamic tensile strengths of ZrB 2 −20%SiC composites at different loading rates are listed in Figure . As reported in study, the ZrB 2 −SiC composite has an obvious strain rate effect under dynamic compression. Correspondingly, the significant rate effect of dynamic tensile strength for the ZrB 2 −SiC composite under dynamic indirect tensile tests can be observed.…”

“…For quasi‐brittle materials, the fracture is not instantaneous, but rather a certain time is required for crack initiation. Wang et al has pointed out that an obvious time‐dependence of the dynamic compressive fracture for ZrB 2 –20%SiC composite can be observed at different strain rates. Moreover, dynamic compressive strength decreases with the increase in critical fracture time.…”

“…Moreover, increasing efforts have been made to investigate the mechanical properties of ZrB 2 ‐based ceramics. Results show that ZrB 2 ‐based ceramics exhibit relatively high compressive strength (1819 MPa for ZrB 2 –SiC and 907.6 MPa for ZrB 2 −SiC−graphite). The flexural strengths are 463 ± 53 MPa for ZrB 2 −20%SiC ceramic and 492 ± 49 MPa for ZrB 2 −30%SiC ceramic at room temperature .…”

“…In the literatures, the dynamic compressive behavior of ZrB 2 ‐based ultra‐high‐temperature ceramics has been comprehensively investigated, including dynamic compressive strength, dynamic deformation, critical strain, and the dynamic compressive fracture mechanism. However, relative low tensile strength of brittle material is a critical parameter to determine the failure under thermal shock environment.…”

Experimental and numerical investigation of the dynamic response of a ZrB2‐SiC ceramic under uniaxial compression

“…However, the dynamic mechanical behavior of the ZrB 2 ‐SiC ceramic with respect to the strain rate has not been deeply investigated yet. It was noted that the compression strength and failure mode of the ZrB 2 ‐based UHTC showed obvious strain rate dependence in our previous studies 5–7 . Therefore, more attentions should be paid to the strain rate‐dependent mechanical response of UHTCs under the high strain rate of loading conditions.…”