In this study, molecular dynamics simulations were employed to investigate the effect of symmetrical tilt grain boundaries (STGBs) on the cascade collision evolution at the SiC/PyC interface. We observed that the tilt angle size of grain boundary (GB) spatial structures significantly influences both the type and number of defects caused by primary knock-on atom (PKA) collisions at the interface, altering the cascade damage morphology. Under the PKA range from 1.5$$keV to 15$$keV at 1000$$K, the interplay between GB and interface damage throughout various cascade collision stages impacts defect generation and PKA efficiency. Integrating the analyses of displacement cascade morphology, threshold displacement energy (TDE), and Frenkel pairs (FPs) evolution, it is evident that GBs introduced into the SiC/PyC interface with single crystals exhibit reduced defect absorption efficiency. This implies the existence of competing mechanisms of GB damage and interfacial damage. Notably, the GB plane near the interface exhibits enhanced irradiation resistance and atomic arrangement stability compared to areas without GB. Overall, our results offer crucial insights into the irradiation resistance mechanics of ceramic composite interfaces, laying the groundwork for future studies.

在本研究中，采用分子动力学模拟研究对称倾斜晶界（STGB）对 SiC/PyC 界面级联碰撞演化的影响。我们观察到，晶界（GB）空间结构的倾斜角大小显着影响界面处初级碰撞原子（PKA）碰撞引起的缺陷的类型和数量，从而改变级联损伤形态。 PKA范围从1.5以下$$keV 至 15$$1000 keV$$K，在各个级联碰撞阶段，GB 和界面损伤之间的相互作用会影响缺陷的产生和 PKA 效率。综合位移级联形态、阈值位移能 (TDE) 和 Frenkel 对 (FP) 演化的分析，很明显，引入单晶 SiC/PyC 界面的 GB 会降低缺陷吸收效率。这意味着晶界损伤和界面损伤存在竞争机制。值得注意的是，与没有GB的区域相比，界面附近的GB平面表现出增强的耐辐照性和原子排列稳定性。总的来说，我们的结果为陶瓷复合材料界面的耐辐照力学提供了重要的见解，为未来的研究奠定了基础。