Effect of proton and neutron irradiation on the structure and properties of ZTA composite ceramics

This paper presents the results of the influence of proton and neutron irradiation on the structure and properties of α- Al 2 O 3 + n% YSZ (ZrO 2 + 3 mol.% Y 2 O 3 ) (n = 0, 1, 5, 10, 15 wt.%) composite ceramics. Powdered mixtures of metastable phases γ/θ-Al 2 O 3 was the basis for producing the composite ceramics. The irradiation was carried out at the EG-5 accelerator (FLNP, JINR) using protons and neutrons. The proton irradiation dose with an energy of 2 MeV was (D p ) = 1·10 17 ions/cm 2 , while for neutrons with an energy of 4.5 MeV it was (D n ) = 2·10 12 particles/cm 2 . Investigation of the surface structure by SEM revealed the formation of a large number of defects in the structure of ZTA ceramics as a result of the impact of high-energy particles. It was found that the largest number of defects were formed in the material composed of α-Al 2 O 3 + 10% YSZ due to neutron irradiation, leading to structural degradation and a reduction in the physical and mechanical properties of the composite ceramics. In addition, SEM analysis recorded the effect of grain fragmentation of YSZ in the composite ceramics under the influence of proton and neutron irradiation. This resulted in a significant reduction in the average grain size of the zirconia matrix filler and changes in the structure of the composite ceramics. It was established that the hardness and density of the studied ceramics exhibited a non-monotonic behaviour depending on the concentration of the YSZ alloying addition. In the materials containing 5 and 15% YSZ, minimum values of the physical and mechanical properties were observed due to the effect of mutual protection of the powder mixtures from crystallisation during annealing (5% YSZ) and the formation of YSZ grain agglomerates during sintering (15% YSZ)