Progress in Solid Mechanics, vol. 4

Sneddon, I. N.; Hill, Robert H.; Jahsman, W. E.

doi:10.1115/1.3625865

Cited by 11 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using relations developed by Sneddon, [17] the contact area, in turn, may be related to the measured contact stiffness, S, by S = 2bE r (A/p) 1/2 , where b is a constant that depends on the geometry of the indenter (b = 1.034 for a Berkovich indenter) and E r is the reduced elastic modulus given by 1/E r = (1 À m 2 )/E + (1 À m i 2 )/E i , where E and m are the elastic modulus and Poisson's ratio for the sample, respectively, and E i and m i are the same quantities for the indenter. All parameters were calculated with the inbuilt software in the instrument.…”

Section: Methodsmentioning

confidence: 99%

Mechanical Properties and Nanocrystallization Behavior of Al-Ni-La Alloys

Sahu

Chatterjee

Sahoo

2010

Metall Mater Trans A

View full text Add to dashboard Cite

Rapidly solidified Al 89 Ni 6 La 5 ribbons were obtained by induction melting and ejecting the melt onto a rotating Cu wheel in an Ar atmosphere. The ribbons were investigated by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), transmission electron microscopy (TEM), microindentation, and nanoindentation techniques. The XRD and TEM studies revealed that the ribbon was fully amorphous; however, DSC did not show any glass transition. The alloy undergoes two stages of crystallization. The growth of fcc-Al is responsible for the first stage, and precipitation of Al 3 Ni and Al 11 La 3 is responsible for the second stage of crystallization. Microhardness of ribbons in the as-melt-spun, partially, and fully devitrified conditions was examined and subsequently correlated with evolved microstructure. Significant improvement in hardness was observed, with the progress of primary nanocrystallization, due to the effective barrier to shear band by a hard La-rich shell around the fcc-Al nanocrystals and enrichment of the remaining amorphous matrix by the solute elements. The pile up of materials in the form of semicircular shear bands was observed around all the indentations. During nanoindentation, it was observed that hardness and modulus values were initially increased and then decreased. The reasons for such observation were also discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

Mechanical Properties and Nanocrystallization Behavior of Al-Ni-La Alloys

Sahu

Chatterjee

Sahoo

2010

Metall Mater Trans A

View full text Add to dashboard Cite

show abstract

“…The power dissipation map was composed of various η values at different deformation temperatures and strain rates. Based on the extremum principle of irreversible thermodynamics, the instability criterion that was applied to the large plastic flow was given by Equation (6) [ 25 ].…”

Section: Resultsmentioning

confidence: 99%

High Temperature Deformation Behavior of In-Situ Synthesized Titanium-Based Composite Reinforced with Ultra-Fine TiB Whiskers

Liu

et al. 2018

Materials

View full text Add to dashboard Cite

A TiB/Ti-6Al-4V composite reinforced with ultra-fine TiB whiskers (UF-TiB) was prepared by the powder metallurgy method. High temperature compression tests were carried out to study the hot deformation behavior of the UF-TiB/Ti-6Al-4V composite. The compressive deformation was performed in the temperature range of 900–1200 °C and the strain rate range of 0.001–10 s−1. The results showed that stable flow occurred at the condition of 900–1200 °C/0.001–0.01 s−1. The optimum working condition was 900 °C/0.001 s−1, with the deformation mechanism of dynamic recrystallization (DRX). Instable flow occurred when the strain rate was higher than 0.01 s−1, where the failure modes included adiabatic shear deformation, whisker breakage and whisker/matrix debonding. The deformability of the UF-TiB/Ti-6Al-4V composite was much better than the traditional casted and the pressed + sintered TiB/Ti-6Al-4V composites, which are typically reinforced with coarse-grained TiB whiskers. The high deformability was primarily attributed to the ultra-fine reinforcements, which could coordinate the deformation more effectively. In addition, a fine matrix microstructure also had a positive effect on deformability because the fine matrix microstructure could improve the grain boundary sliding.

show abstract

“…For the as-deposited TiC film single contact between the indenter tip and a homogeneous, investigated here, the maximum indentation depth of the perfectly elastic material having a smooth surface. [24] These smallest indentation exceeds the rms roughness by a factor assumptions become more difficult to meet as the size of of 22 and it can be assumed that the hardness values obtained the indentations decreases, for the following reasons:…”

Section: A Load-variation Methodsmentioning

confidence: 99%

“…Thus, for materials having a high ratio of yield stress ( y ) to Young's modulus (E ), e.g., rubber, the elastic properties will dominate the contact hardness rather than the plastic properties, in contrast to the traditional hardness, where the elastic properties do not influence the hardness value determined. For metals, however, the ratio y /E, and thus the If the initial deformation upon unloading is purely elastic, the reduced elastic modulus E r can be described by [24] B. Roughness…”

Section: Hardness Measurements and Data Evaluationmentioning

confidence: 99%

Hardness-depth profiling on nanometer scale

Kunert

Baretzky

Baker

et al. 2001

Metall Mater Trans A

View full text Add to dashboard Cite

Three methods for hardness-depth profiling were applied to a 200-nm-thick TiC film deposited onto a Ti-6Al-4V substrate. The methods were evaluated and compared with regard to their ability to detect local changes in hardness with a depth resolution on the order of a few nanometers. In the cross section method (CSM), the indentations are performed on a cross section of the sample, i.e., in a direction perpendicular to the hardness gradient. In the load-variation method (LVM) and in the constant-load method (CLM), the indentations are made in the direction of the hardness gradient, i.e., perpendicular to the as-prepared surface. In the LVM, the hardnessdepth profile is assessed using a stepwise increase of the maximum load applied to the surface. In the CLM, sublayers are removed successively by ion sputtering and hardness measurements are performed at each newly exposed surface using the same low maximum load. The CSM revealed a nearly constant hardness across the TiC film and a sharp transition from the TiC film to the Ti-6Al-4V substrate. The hardness profile obtained using the LVM and the CLM is smeared out because the recorded response is due to both the TiC film and the underlying softer Ti-6Al-4V substrate.

show abstract

Progress in Solid Mechanics, vol. 4

Cited by 11 publications

References 0 publications

Mechanical Properties and Nanocrystallization Behavior of Al-Ni-La Alloys

Mechanical Properties and Nanocrystallization Behavior of Al-Ni-La Alloys

High Temperature Deformation Behavior of In-Situ Synthesized Titanium-Based Composite Reinforced with Ultra-Fine TiB Whiskers

Hardness-depth profiling on nanometer scale

Contact Info

Product

Resources

About