材料期刊网

目的研究梯度材料抗低应力多冲碰撞塑性变形能力。方法对纯铁材料、铁镍突变材料和铁镍梯度材料进行多次冲击碰撞试验，分析3种材料的累积变形量、不同层深处的应变和形变硬化程度、表面微观组织。结果总形变量、不同层深处的应变和形变硬化程度方面，纯铁材料略大于铁镍突变材料，远大于铁镍梯度材料。铁镍突变材料和纯铁材料表层为单相多晶组织，且界面密度较小；铁镍梯度材料表层为多相多晶组织，且界面的密度大，其形变被抑制。结论铁镍梯度材料的抗低应力多冲碰撞塑性变形的能力最强，铁镍突变材料次之，纯铁材料最差。

ABSTRACT:Objective To study the resistance to plastic deformation of iron-nickel gradient materials under the low and repeated impact stress. Methods Repeated impact tests were conducted on pure iron material, iron-nickel mutation material and iron-nickel gradient material. The cumulative deformation, strain and deformation hardening degree with different depths, and the surface mi-crostructure were analyzed and compared. Results The total deformation, strain and deformation hardening degree with different depths of the pure iron material were a little larger than those of the iron-nickel mutation material, and much larger than those of the iron-nickel gradient material. The surface of the pure iron material and the iron-nickel mutation material was single-phase polycrys-talline structure and the density of interface was small. The surface of the iron-nickel gradient material was multiphase polycrystal-line structure, the density of interface was larger, and the plastic deformation was more suppressed. Conclusion For the resistance ability to plastic deformation under the low and repeated impact stress, the iron-nickel gradient material was the strongest, followed by the iron-nickel mutation material, and the pure iron material specimen was the worst.