Effects of irradiation on nano-pore phenol-formaldehyde resin infiltrated IG-110 graphite

Abstract

• The PF filler in pores of IG-110 shrinks after irradiation. • The irradiated densified isostatic graphite has smaller change ratio of L a . • The irradiation behavior depends on the initial graphitization degree of graphite. Iso-molded nuclear graphite (IG-110) was infiltrated with phenol–formaldehyde (PF) resin to get the densified isostatic graphite with different bulk density (IG-110-PF, 1.86 g/cm 3 and IG-110-PF-D, 1.91 g/cm 3 ). The IG-110-PF and IG-110-PF-D samples were irradiated with 7 MeV Xe 26+ to study their surface topography and microstructure evolution. The impregnation process of PF resin affects the initial graphitization degree of graphite, which lead to the difference in irradiation behavior. Due to the irradiation-induced graphitization, the PF filler (carbonized products of PF resin infiltrated into pores) in pores of IG-110 shrinks after irradiation, which confirmed by the smaller change ratio of crystallite size along the a-axis direction (L a ) in IG-110-PF and IG-110-PF-D after irradiation than IG-110. L a of IG-110-PF-D decreased with the dose increase, resulting from the introduction of irradiation-induced in-plane defects, which is similar to IG-110.The increase in L a of PF filler in IG-110-PF and decrease of increase rate in dislocation density after irradiation with surface irradiation dose of 0.02–0.11dpa, provide supporting evidence for the change of PF filler. The difference in irradiation behavior confirms that disordered structure of PF filler and initial crystallinity play an important role in microstructure evolution.