Study Of The Radiation-induced Microstructural Evolution Of Zr-based Amorphous Alloy

The nuclear power is a good choice to solve the energy problem.It is known that the service life of the reactor is dependent on the nuclear materials,while whose performance probably are failed in the terrible service environment after a long-time service.Amorphous alloys have excellent physical,chemical and mechanical properties,which are expected to be a new type of reactor materials.The disordered structure of amorphous alloys might lead to different radiation response from that of crystal alloys.However,so far,the radiation-induced structural and properties changes in the amorphous alloys are unknown.In this paper,synchrotron radiation technology combined with molecular dynamics was applied to analyze the radiation-induced microstructural changes in amorphous alloys.Synchrotron radiation technologies are used to detect the microstructure of prepared samples and irradiated samples,respectively.Both atomic models are obtained by RMC method.The atomic structure of the prepared model and irradiated model are analyzed,and we found that there are slight differences between these two models.It is found that,compared with crystalline alloys,metallic glasses have some specific structural responses to neutron irradiation.Although neutron irradiation can induce transient vacancy-like defects in metallic glasses,they are fully annihilated after structural relaxation by rearrangement of free volumes.In addition,the rearrangement of free volumes depends strongly on constituent elements.In particular,the change in free volumes occurs around the Zr atoms,rather than the Cu centers.This implies that there is a feasible strategy for identifying glassy materials with high structural stability against neutron irradiation by tailoring the microstructures,the systems,or the compositions in alloys.In addition,the atomistic structural evolution of metallic glasses under neutron irradiation is investigated,by performing a molecular dynamics simulation.It is found that irradiation-induced vacancy-like defects do appear in microstructure,due to the collision cascades.However,these defects are transient and unstable that they are fully annihilated after structural relaxation.In particular,as specific structural characters in metallic glasses,free volumes,are detected to rearrange themselves to annihilate these transient defects,so that the problems of irradiation-induced structural instability and energy imbalance are solved.This work is helpful in evaluating the structural stability of metallic glasses under neutron irradiation.