Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys
碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 99 === Nanoindentation has been widely used for measuring mechanical behavior of nanocrystalline (nc) metals that cannot be measured by tensile and compressive test. The hardness and elastic modulus are usually obtained by Oliver and Pharr method. However, this may...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Others |
Language: | zh-TW |
Published: |
2011
|
Online Access: | http://ndltd.ncl.edu.tw/handle/48745785710634301249 |
id |
ndltd-TW-099NSYS5124015 |
---|---|
record_format |
oai_dc |
spelling |
ndltd-TW-099NSYS51240152015-10-19T04:03:18Z http://ndltd.ncl.edu.tw/handle/48745785710634301249 Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys 電鍍鎳與鎳鐵合金集合組織與機械性質研究 Lian-Hao Yi 易廉皓 碩士 國立中山大學 材料與光電科學學系研究所 99 Nanoindentation has been widely used for measuring mechanical behavior of nanocrystalline (nc) metals that cannot be measured by tensile and compressive test. The hardness and elastic modulus are usually obtained by Oliver and Pharr method. However, this may not be true for materials showing viscoelastic characteristics. This study aims at clarifying the effect of testing parameters, especially loading rate and holding time, on the hardness and elastic modulus of a nanocrystalline Fe-51Ni coating obtained in nanoindentation tests as the material exhibits anelastic and creep characteristics. An analytical method based on the correspondence principle for linear viscoelasticity was developed. The holding displacement-time data obtained in indentation creep tests at a high loading rate of 20 mN/s were analyzed and material parameters related to the elastic, anelastic and creep characteristic were derived using a model containing one Maxwell unit and two Kelvin units. The anelastic deformation thus contains at least two relaxation processes having relaxation times of 0.37 s and 6.8 s, respectively and the creep deformation is described by a viscosity value of 4.2x104 GPa.s for the alloy in an as-deposited state. Moreover, electrodeposited (ED) Ni was analyzed by electron backscatter diffraction. Results indicated that the ED Ni exhibits a bimodal distribution of grain size. The grains having sizes larger than 2 μm shows a strong fiber texture of <100>//ND, whereas the small grains (<2 μm) are mainly randomly oriented. L. W. Chang 張六文 2011 學位論文 ; thesis 62 zh-TW |
collection |
NDLTD |
language |
zh-TW |
format |
Others
|
sources |
NDLTD |
description |
碩士 === 國立中山大學 === 材料與光電科學學系研究所 === 99 === Nanoindentation has been widely used for measuring mechanical behavior of nanocrystalline (nc) metals that cannot be measured by tensile and compressive test. The hardness and elastic modulus are usually obtained by Oliver and Pharr method. However, this may not be true for materials showing viscoelastic characteristics. This study aims at clarifying the effect of testing parameters, especially loading rate and holding time, on the hardness and elastic modulus of a nanocrystalline Fe-51Ni coating obtained in nanoindentation tests as the material exhibits anelastic and creep characteristics. An analytical method based on the correspondence principle for linear viscoelasticity was developed. The holding displacement-time data obtained in indentation creep tests at a high loading rate of 20 mN/s were analyzed and material parameters related to the elastic, anelastic and creep characteristic were derived using a model containing one Maxwell unit and two Kelvin units. The anelastic deformation thus contains at least two relaxation processes having relaxation times of 0.37 s and 6.8 s, respectively and the creep deformation is described by a viscosity value of 4.2x104 GPa.s for the alloy in an as-deposited state.
Moreover, electrodeposited (ED) Ni was analyzed by electron backscatter diffraction. Results indicated that the ED Ni exhibits a bimodal distribution of grain size. The grains having sizes larger than 2 μm shows a strong fiber texture of <100>//ND, whereas the small grains (<2 μm) are mainly randomly oriented.
|
author2 |
L. W. Chang |
author_facet |
L. W. Chang Lian-Hao Yi 易廉皓 |
author |
Lian-Hao Yi 易廉皓 |
spellingShingle |
Lian-Hao Yi 易廉皓 Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
author_sort |
Lian-Hao Yi |
title |
Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
title_short |
Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
title_full |
Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
title_fullStr |
Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
title_full_unstemmed |
Study on texture and mechanical properties of electrodeposited Ni and NiFe alloys |
title_sort |
study on texture and mechanical properties of electrodeposited ni and nife alloys |
publishDate |
2011 |
url |
http://ndltd.ncl.edu.tw/handle/48745785710634301249 |
work_keys_str_mv |
AT lianhaoyi studyontextureandmechanicalpropertiesofelectrodepositedniandnifealloys AT yìliánhào studyontextureandmechanicalpropertiesofelectrodepositedniandnifealloys AT lianhaoyi diàndùnièyǔniètiěhéjīnjíhézǔzhīyǔjīxièxìngzhìyánjiū AT yìliánhào diàndùnièyǔniètiěhéjīnjíhézǔzhīyǔjīxièxìngzhìyánjiū |
_version_ |
1718093892131225600 |