纳米孔洞对单晶/多晶Ni复合体拉伸性能的影响  

Effect of Nanopores on Tensile Properties of Single Crystal/Polycrystalline Nickel Composites

作　　者：李源才 江五贵[1] 周宇 LI Yuancai;JIANG Wugui;ZHOU Yu(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063

出　　处：《金属学报》2020年第5期776-784,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.11772145。

摘　　要：采用分子动力学方法研究了预制纳米孔洞缺陷对单晶/多晶Ni复合体拉伸性能的影响。结果表明,与多晶Ni相比,单晶Ni能够提高单晶/多晶Ni复合体的抗拉强度。对比了孔洞位置分布对单晶/多晶Ni复合体拉伸性能的影响。模拟结果表明,处于单晶区域的纳米孔洞缺陷显著加剧了单晶/多晶Ni复合体界面的断裂。相反,孔洞处于多晶区域时,界面一侧的单晶Ni阻碍了多晶Ni侧非晶化的传播,抑制了孔洞向界面一侧的单晶扩展。随后讨论了界面孔洞的孔隙率对单晶/多晶Ni复合体拉伸性能的影响。结果表明,当孔隙率超过0.8%后,单晶/多晶Ni复合体的抗拉强度迅速下降。最后分析了当保持界面孔洞孔隙率不变的情况下空洞数量对拉伸性能的影响,结果显示,相比于大孔洞,分散的小孔洞具有更好的拉伸性能。The performance of the new generation aero-engine is strongly dependent on the application of integral blisk technologies,while the high-risk failure of integral disk joints severely restricts the promotion of those technologies.Therefore,the molecular dynamics method is used to investigate the influence of nanopores on the tensile properties of single crystal/polycrystalline Ni composites.The results show that the addition of single crystal nickel can increase the tensile strength of single crystal/polycrystalline Ni compared with polycrystalline nickel.The influence of pore position distribution on the tensile properties of single crystal/polycrystalline Ni is investigated.The simulation results show that nanopore defects in a single crystal region significantly aggravate the fracture at the single crystal/polycrystalline Ni interface.Pores not only penetrate the interface of composites but also rapidly expand inside the single crystal and the polycrystalline crystal,in which the interface of composites is further reduced resulting in the failure acceleration of single crystal/polycrystalline Ni composites.On the contrary,when the pores are in a polycrystalline region,the interface of single crystal/polycrystalline Ni hinders the amorphization of the polycrystalline nickel side and inhibits the pores from spreading toward the interface.When the pores are in the interface region,the pores do not continue to expand into the single crystal,but propagate inside the polycrystalline crystal.The effect of the porosity of interface pores on the tensile properties of single crystal/polycrystalline Ni is also discussed.It is found that the tensile strength of single crystal/polycrystalline Ni decreases rapidly when the void porosity exceeds 0.8%.Finally,the influence of the number of voids on the tensile properties while maintaining the porosity of the interface pores is analyzed.When the porosity of the prefabricated pores of the interface is kept constant at 0.8%,the larger the number of pores(i.e.,the smaller the pore

关 键 词：分子动力学 预制纳米孔洞 单晶/多晶Ni 复合体 拉伸性能 孔洞位置 孔隙率 

分 类 号：TB31[一般工业技术—材料科学与工程]