Hall-petch strengthening for the microhardness of twelve nanometer grain diameter electrodeposited nickel

Hughes, G.; Smith, Sherie; Pande, C. S.; Johnson, H.R.; Armstrong, Ronald W.

doi:10.1016/0036-9748(86)90219-x

Cited by 331 publications

(88 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accordingly, we have used the XRD grain size, d, to compile the Hall-Petch plot shown in Figure 10, which shows the Vicker's microhardness (H) as a function of d 1/2 . For comparison with the present data, we have also included data from nominally pure Ni [10,11,[61][62][63] and Co. [57] At grain sizes above ϳ15 nm (to the left of Figure 10), we see that all of the data from the present study (Ni-80Co), as well as from prior literature on pure Ni and Co, fall into a reasonably common trend that follows the expected Hall-Petch scaling. This result confirms the expectations developed previously, and supports the notion that twin boundaries are effective Hall-Petch strengtheners.…”

Section: Role Of Grain Boundary Character On Hardness Trendsmentioning

confidence: 77%

See 1 more Smart Citation

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Ferreira

Schuh

2005

Metall Mater Trans A

View full text Add to dashboard Cite

We present an experimental approach to systematically produce nanostructures with various grain sizes and twin densities in the Ni-Co binary system. Using electrodeposition with various applied current densities and organic additive contents in the deposition bath, we synthesize nanostructured fcc and hcp solid solutions with a range of compositions. Due to the low stacking fault energy (SFE) of these alloys, growth twins are readily formed during deposition, and by adjusting the deposition conditions, a range of twin boundary densities is possible. The resulting nanostructured alloys cannot be described by a single characteristic length scale, but instead must be characterized in terms of (1) a true grain size pertaining to general high-angle grain boundaries and (2) an effective grain size that incorporates twin boundaries. Analysis of Hall-Petch strength scaling for these materials is complicated by their dual length scales, but the hardness trends found in Ni-80Co are found to be roughly in line with those seen in pure nanocrystalline nickel.

show abstract

Section: Role Of Grain Boundary Character On Hardness Trendsmentioning

confidence: 77%

“…The presence of lattice fringes up to the boundary suggests that there is no amorphous film at the boundaries in this alloy. [10,11,[61][62][63] and pure Co. [57] The dashed trend lines are present for illustrative purposes only.…”

Section: Role Of Grain Boundary Character On Hardness Trendsmentioning

confidence: 99%

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Ferreira

Schuh

2005

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…Additionally, α phase laths frequently occupying the β grain boundaries aligned to the shear direction. This grain refinement consequently lead to an approximate 50% increase in hardness from that of the starting material, primarily due to locally enhanced Hall-Petch strengthening [18]. In regions adjacent to the fine equiaxed zone, there is a transition to firstly larger elongated β grains with α laths aligned to the shear direction, and then to larger diamond shaped β grains with α phase often located on their diagonal axes.…”

Section: Discussionmentioning

confidence: 99%

Insights Into Machining of a β Titanium Biomedical Alloy from Chip Microstructures

Kent¹,

Rashid²,

Bermingham³

et al. 2018

Preprint

View full text Add to dashboard Cite

bstract: New metastable β titanium alloys are receiving increasing attention due to their excellent biomechanical properties and machinability is critical to their uptake. In this study machining chip microstructure have been investigated to gain an understanding of strain and temperature fields during cutting. For higher cutting speeds, ≥60 m/min, the chips have segmented morphologies characterised by a serrated appearance. High levels of strain in the primary shear zone promote formation of expanded shear band regions between segments which exhibit intensive refinement of the β phase down to grain sizes below 100 nm. The presence of both α and β phases across the expanded shear band suggests that temperatures during cutting are in the range of 400-600°C. For the secondary shear zone, very large strains at the cutting interface result in heavily refined and approximately equiaxed nanocrystalline β grains with sizes around 20-50 nm, while further from the interface the β grains become highly elongated in the shear direction. An absence of the α phase in the region immediately adjacent to the cutting interface indicates recrystallization during cutting and temperatures in excess of the 720°C β transus temperature.

show abstract

“…In essence, according to the previous work [3] , the change of grain structure directly results in an uncertainty of surface material property and affects severely machining quality. During cutting process, the most commonly method to reveal the interactive relation between surface properties and microstructure is Hall-Petch (H-P) equation [28][29] . However, models on size effect remains proportional to internal grain, which cannot obtain an accurate evolution mechanism of microscopic deformation field and mechanical properties of grain refining in most of studies [30] .…”

Section: The Effect Of Grain Size On Microscopic Deformation Fieldmentioning

confidence: 99%

Evolution of surface grain structure and mechanical properties in orthogonal cutting of titanium alloy

Bai

Tong

et al. 2016

J. Mater. Res.

View full text Add to dashboard Cite

Abstract:In this study, a mesoscale dislocation simulation method was developed to study the orthogonal cutting of Titanium alloy. The evolution of the surface grain structure and its effects on the mechanical properties was studied using two-dimensional climb assisted dislocation dynamic technology. The motions of edge dislocations in an elastic matrix such as dislocation nucleation, lock, interaction with obstacles and grain boundaries, and annihilation were tracked. The results showed that the machined surface has a graded microstructure composed of ultrafine grains. A grain refinement process was observed in micro-cutting of titanium alloy. The process can be described as follows: (i) the development of dislocation lines in original grains, (ii) the formation of dense dislocation bands, (iii) the transformation of dislocation bands into subgrain boundaries, and (iv) the continuous dynamic recrystallization in subgrain boundaries. The fine-grains formed in this process bring appreciable scale effect and a mass of dislocations pile up in the grain boundary and persistent slip band (PSB). In particular, the flow stress and hardening rate was reduced by dislocation climb. However, this effect is significantly weakened when grain size was less than 1.65 µm. In addition, a Hall-Petch type relation is predicted depending on the amount of slips, the dislocation density, the grain arrangement and the range of grain sizes to which a Hall-Petch expression is fit. The numerical results obtained were compared with experimental data gathered from literature and a satisfied agreement was found.

show abstract

Hall-petch strengthening for the microhardness of twelve nanometer grain diameter electrodeposited nickel

Cited by 331 publications

References 7 publications

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Insights Into Machining of a β Titanium Biomedical Alloy from Chip Microstructures

Evolution of surface grain structure and mechanical properties in orthogonal cutting of titanium alloy

Contact Info

Product

Resources

About

Hall-petch strengthening for the microhardness of twelve nanometer grain diameter electrodeposited nickel

Cited by 331 publications

References 7 publications

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Nanostructured Ni-Co alloys with tailorable grain size and twin density

Insights Into Machining of a &beta; Titanium Biomedical Alloy from Chip Microstructures

Evolution of surface grain structure and mechanical properties in orthogonal cutting of titanium alloy

Contact Info

Product

Resources

About

Insights Into Machining of a β Titanium Biomedical Alloy from Chip Microstructures