TY - JOUR
T1 - Investigation of Internal Cracks in Epoxy-Alumina Using In Situ Mechanical Testing Coupled with Micro-CT
AU - Tang, Yichun
AU - Su, Kangning
AU - Man, Ruyi
AU - Hillman, Michael C.
AU - Du, Jing
N1 - Funding Information:
This research is supported by the National Science Foundation (#1826221). The authors are grateful to the program manager, Dr. Siddiq Qidwai, for his encouragement and support. Appreciation is extended to Dr. Timothy Stecko of Penn State Center for Quantitative Imaging for technical assistance with micro-CT scanning.
Publisher Copyright:
© 2021, The Minerals, Metals & Materials Society.
PY - 2021/8
Y1 - 2021/8
N2 - Polymer-ceramic composites are widely used in biomedical applications. This paper presents the results of an experimental investigation on the crack extension inside epoxy-alumina. Specimens with 5 vol.%, 10 vol.%, …, 25 vol.% fillers fractions were fabricated. Three-point bending on single-edge notched bend specimens were performed using conventional mechanical tester and in situ mechanical tester coupled with micro-CT, respectively. Fracture toughness was measured to be 2.10–2.51 MPam, and it decreased with increasing filler fraction. When cracks were shorter than 0.88 mm, crack resistance for 5 and 25 vol.% epoxy-alumina was similar. Beyond 0.88 mm, 25 vol.% epoxy-alumina exhibited no crack resistance, whereas stress intensity factor kept increasing in 5 vol.% epoxy-alumina. The matrix-particle interfaces were the weakest link, where cracks often initiated from. Crack bridging by uncracked ligament and crack deflection were commonly observed toughening mechanisms. To design robust epoxy-alumina composites, increasing matrix-particle interface strength is recommended for future work.
AB - Polymer-ceramic composites are widely used in biomedical applications. This paper presents the results of an experimental investigation on the crack extension inside epoxy-alumina. Specimens with 5 vol.%, 10 vol.%, …, 25 vol.% fillers fractions were fabricated. Three-point bending on single-edge notched bend specimens were performed using conventional mechanical tester and in situ mechanical tester coupled with micro-CT, respectively. Fracture toughness was measured to be 2.10–2.51 MPam, and it decreased with increasing filler fraction. When cracks were shorter than 0.88 mm, crack resistance for 5 and 25 vol.% epoxy-alumina was similar. Beyond 0.88 mm, 25 vol.% epoxy-alumina exhibited no crack resistance, whereas stress intensity factor kept increasing in 5 vol.% epoxy-alumina. The matrix-particle interfaces were the weakest link, where cracks often initiated from. Crack bridging by uncracked ligament and crack deflection were commonly observed toughening mechanisms. To design robust epoxy-alumina composites, increasing matrix-particle interface strength is recommended for future work.
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U2 - 10.1007/s11837-021-04714-x
DO - 10.1007/s11837-021-04714-x
M3 - Article
AN - SCOPUS:85105805194
SN - 1047-4838
VL - 73
SP - 2452
EP - 2459
JO - JOM
JF - JOM
IS - 8
ER -