Temperature dependent mechanical properties and thermal activation plasticity of nanocrystalline and coarse grained Ni-18.75 at.% Fe alloy

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Tabachnikova, E.D.^1 ; Podolskiy, A.V.^1 ; Smirnov, S.N.^1 ; Psaruk, I.A.^1 ; Liao, P.K.^2

B. Verkin Institute for Low Temperature Physics and Engineering, NASU, Lenin Ave. 47, Kharkov, 61103, Ukraine^1

Tennessee University, 37996, Knoxville, United States^2

关键词: Different mechanisms;    Dislocation interaction;    Nanocrystalline state;    Strain rate sensitivity;    Temperature dependence;    Temperature dependent;    Thermal activation analysis;    Uni-axial compression;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012105/pdf
DOI  :  10.1088/1757-899X/63/1/012105

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Mechanical properties of Ni-18.75 at.% Fe in coarse grained (average grain size 15 gm) and nanocrystalline (average grain size 22 nm) states were studied in uniaxial compression in the temperature range 4.2-350 K. Temperature dependences of the flow stress, strain rate sensitivity and activation volume of plastic deformation were measured. The thermal activation analysis of the experimental data has been fulfilled for the the plastic deformation value of 2 %. It was shown that plastic deformation in temperature range from 35 to 350 K in both studied structural states has the thermally activated type. Comparative analysis of low temperature thermal activation plastic deformation was carried out for the alloy in coarse grained and nanocrystalline states. Empirical estimates of parameters of the dislocation interaction with local barriers and internal stress value estimates were obtained for the both studied structural states. Analysis of the results indicates that different mechanisms control the thermal activation plasticity of the Ni-18.75 at.% Fe alloy in coarse grained and nanocrystalline states. Possible mechanisms, which control plactisity of the studied states, are disscussed.