Li Ben, Dong Chao, Yu Jingui, Zhang Qiaoxin, Zhou Hongyan, Liu Rong
School of Mechanical and Electronic Engineering, Wuhan University of Technology Wuhan 430070 P. R. China
State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology Wuhan 430074 P. R. China.
RSC Adv. 2018 Jun 15;8(39):22127-22135. doi: 10.1039/c8ra03129k. eCollection 2018 Jun 13.
Engine turbine blades are subjected to high-temperature and high-speed fragment impacts during use, and the ability of the blades to resist shocks affects their reliability. At present, there are few studies on the ability to withstand shocks of Ni-based single crystal alloys, especially with regards to their mechanical behaviour and microstructural evolution under shock loading. The solutions to the above problems can further help us understand the mechanisms of the mechanical responses and microstructural evolution of Ni-based single crystal alloys under shock loading. Thus, we study the mechanical behaviour and microstructural evolution characteristics of Ni-based single crystal alloys with different crystal orientations under shock loading using molecular dynamics simulations. We find that the (001) phase interface has the strongest impediment ability due to its dislocation network structure and the expansion of dislocations, which lead to the greatest reinforcing effect on the matrix. The penetration force of the (001) phase interface is the greatest with fragment penetration. Moreover, the energy dissipation capacity of the (001) phase interface is the highest with fragment penetration because it has the strongest resistance to shock loading. The second highest is the (110) phase interface, and the minimum dissipation capacity comes from the (111) phase interface. This study has an important theoretical significance for the in-depth understanding of the failure mechanisms of Ni-based single crystal alloys under shock loading.
发动机涡轮叶片在使用过程中会受到高温和高速碎片冲击，叶片的抗冲击能力会影响其可靠性。目前，关于镍基单晶合金抗冲击能力的研究较少，尤其是其在冲击载荷下的力学行为和微观结构演变方面。解决上述问题有助于我们进一步了解镍基单晶合金在冲击载荷下的力学响应和微观结构演变机制。因此，我们使用分子动力学模拟研究了不同晶体取向的镍基单晶合金在冲击载荷下的力学行为和微观结构演变特征。我们发现，(001)相界面由于其位错网络结构和位错扩展而具有最强的阻碍能力，这对基体产生了最大的强化作用。在碎片穿透时，(001)相界面的穿透力最大。此外，在碎片穿透时，(001)相界面的能量耗散能力最高，因为它对冲击载荷的抵抗力最强。其次是(110)相界面，而(111)相界面的耗散能力最小。该研究对于深入理解镍基单晶合金在冲击载荷下的失效机制具有重要的理论意义。
