Irradiation hardening for metallic materials

Investigations on irradiation hardening of metallic materials have much sig- nificance for the design of anti-irradiation materials and engineering applications. Both irradiation-induced defects and gaseous impurities produced by nuclear reactions have dra- matic irradiation effects on the mechanical properties of materials, which include irradiation hardening, irradiation embrittlement and irradiation creep, etc. In this paper we are con- cerned with irradiation hardening, i.e., the strength of materials increases with irradiation, under low irradiation doses and low temperatures of T < 0.3 Tm with Tm the melting temper- ature. Besides, other factors such as the grain size, the grain boundary and the temperature affect mechanical behaviors of irradiated polycrystalline materials. The study of irradia- tion hardening of metallic materials is a multi-scale problem, for which the macroscopic mechanical behaviors of irradiated materials are determined by both the change of interior structures with irradiation at micro-scale and the interactions among irradiated grains at meso-scale. This paper reviews experimental results, numerical simulations and theoretical models for irradiation hardening of metallic materials. Some scientific problems for future study are also presented.