Increasing Cathode Potential of Homogeneous Low Voltage Electron Beam Irradiation (HLEBI) to Increase Impact Strength of Carbon Fiber Reinforced Polycarbonate and Characterization by XPS C1s and O1s Peaks
Year: 2025
Type: article
Abstract: In an interlayered carbon fiber reinforced polycarbonate (CFRPC) composite constructed of nine CF plies alternating between ten PC sheets, designated [PC]10[CF]9, applying homogeneous low voltage electron beam irradiation (HLEBI) at 200 kV cathode potential, with Vc setting at a 43.2 kGy dose, to both finished sample surfaces resulted in a 47% increase in Charpy impact strength and auc at median fracture probability (Pf) of 0.50 over that of untreated, from 118 kJm−2 to 173 kJm−2. Increasingly higher Vc settings of 150, 175, and 200 kV successively increased auc at median-Pf of 0.50 to 128, 155, and 173 kJm−2, respectively. Strengthening is attributed to increasing the HLEBI penetration depth, Dth, into the sample thickness. Since the [PC]10[CF]9 has an inhomogeneous structure, Dth is calculated for each ply successively into the thickness. Scanning electron microscopy (SEM) photos showed a hierarchy of fracture mechanisms from poor PC/CF adhesion in untreated; to sporadic PC adhesion with aggregated CF at 150 kV; to high consolidation of CFs by PC at 200 kV. X-ray photoelectron spectroscopy (XPS) examination of the CF surface in the fracture area showed C1s carbonate O–(C=O)–O and ester O–(C=O)–R peak generation at 289 to 292 eV to be non-existent in untreated; well-defined at 150 kV; and increased in intensity at 200 kV, after which a reduction was observed at 225 kV. Moreover, the 200 kV yielded the largest area sp3 peak at 49.5%, signifying an increase in graphitic edge planes in the CF, apparently as dangling bonds, for increased adhesion sites to PC. For O1s scan, 200 kV yielded the largest area O–(C=O)–O peak at 34%, indicating maximum PC adhesion to CF. At the higher 225 kV, increase in auc at Pf of 0.50 was less, to 149 kJm−2, and XPS indicated a lower amount of O–(C=O)–O groups, apparently by excess bond severing by the higher Vc setting.
Source: Materials
DOI: 10.3390/ma18235471
Authors: Fumiya Sato, Kouhei Sagawa, Helmut Takahiro Uchida, Hirotaka Irie, Michael C. Faudree, Michelle Salvia, Akira Tonegawa, Satoru Kaneko, Hideki Kimura, Yoshitake Nishi
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4417043964