热处理对电沉积Ni-Fe合金箔组织和力学性能的影响

Effect of heat treatment on the microstructure and mechanical properties of electrodeposited Ni-Fe alloy foil

电沉积法制备Ni-Fe合金箔具有工艺简单,能耗低,产品规格不受限制等优点,但其塑性和弹性模量较低限制了其应用发展.为了改善电沉积Ni-Fe合金箔的力学性能并扩大其应用范围,本文通过高温热处理方法改善其力学性能,采用SEM,XRD,EBSD分析手段对电沉积Ni-Fe合金箔晶粒组织和结构进行了分析,通过高温热台显微镜进行原位在线观测晶粒组织的演变过程,并对热处理后的电沉积Ni-Fe合金箔进行力学性能分析.研究表明,热处理过程中电沉积Ni-Fe合金箔经历细晶组织阶段、混晶组织阶段和粗晶组织阶段,其中,在1 000~1 050℃容易发生晶粒异常长大.细晶组织阶段,电沉积Ni-Fe合金箔能够保证较高的强度,且塑性和弹性模量明显提高,综合性能较好;混晶组织阶段,强度和塑性较低,弹性模量有一定程度提高;粗晶组织阶段,强度很低,但塑性和弹性模量有较大程度提高.

The electrodeposition is well known as a technological and economical method to produce large scale and high purity nanocrystalline Ni- Fe alloy foil in one step. However,the low plasticity and elastic modulus restrict its application. In order to improve the mechanical properties and expand the application range of the electrodeposited nanocrystalline Ni- Fe alloy foil,the mechanical properties were improved by heat treatment at high temperatures in this study. The microstructure and texture of the samples were analyzed with a combination of SEM,XRD and EBSD. The evolution of grain microstructure during annealing was in situ investigated using high temperature thermo-stage microscope and the mechanical properties were also studied in this paper. The results indicate that the evolution of grain microstructure of the foil underwent 3stages in the heat treatment process： fine grain microstructure,mixed grain microstructure and coarse grain microstructure. The abnormal grain growth appeared after annealed at 1 000 ~ 1 050 ℃. In the fine grain microstructure stage,the alloy foils obtained a relatively high strength and better comprehensive property. The plastic and modulus were improved significantly. The strength and plasticity of the alloy foils with mixed grain microstructure were low,but the elastic modulus was increased. The strength of the alloy foils with coarse grain microstructure was low,but the plasticity and elastic modulus were greatly improved.