Contribution of damage by multiple crack growth to the strain-rate sensitivity of a polycrystalline alumina at elevated temperatures

1989 ◽  
Vol 24 (2) ◽  
pp. 671-680 ◽  
Author(s):  
D. P. H. Hasselman ◽  
A. Venkateswaran ◽  
K. Y. Donaldson
Keyword(s):  
Strain Rate ◽  
Crack Growth ◽  
Strain Rate Sensitivity ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Multiple Crack ◽  
Polycrystalline Alumina

Strain Rate Sensitivity of Commercial Aluminum Alloys

2019 ◽  
Author(s):  
R.C. Picu
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Solid Solutions ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Solute Diffusion ◽  
Rate Dependent ◽  
Ultrafine Grained ◽  
Using Data

This article presents a review of the strain rate-dependent mechanical behavior of aluminum and its commercial alloys. The importance of strain rate sensitivity (SRS) stems from its relation with ductility and formability. Plastic deformation is stable and localization less likely in alloys with higher SRS. After discussing the basic formulation used to interpret experimental data, the methods used to measure the SRS parameter are presented. This is followed by a brief review of the main mechanisms that render the flow stress sensitive to the deformation rate, including mechanisms leading to positive and negative SRS. The generic dependence of the SRS parameter on the strain, temperature, and strain rate are further presented using data for pure Al. The effect of alloying is analyzed in the context of solid solutions and precipitated commercial alloys. Results on solid solutions are discussed separately at low and elevated temperatures in order to evidence the role of solute diffusion on SRS. This article ends with a brief discussion of the grain size dependence of SRS, with emphasis on recent efforts to produce nanocrystalline and ultrafine-grained materials by severe plastic deformation.

scholarly journals The Effect of Small Additions of Solutes on the Flow Stress and the Strain Rate Sensitivity of Aluminium at Elevated Temperatures

1968 ◽  
Vol 32 (12) ◽  
pp. 1276-1280
Author(s):  
Takao Endo ◽  
Tôru Aramaki ◽  
Toshio Enjyo ◽  
Masao Adachi
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Elevated Temperatures ◽  
Rate Sensitivity

Experimental investigation on strain rate sensitivity of ultra-fine grained copper at elevated temperatures

2011 ◽  
Vol 43 (3) ◽  
pp. 111-118 ◽  
Author(s):  
Tao Suo ◽  
Yu-long Li ◽  
Kui Xie ◽  
Feng Zhao ◽  
Ke-Shi Zhang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Fine Grained

Determination of Material Parameters during Superplastic Forming of AZ31B Magnesium Alloy at Elevated Temperatures in Uniaxial Tensile Test

2015 ◽  
Vol 787 ◽  
pp. 437-441
Author(s):  
S. Ramesh Babu ◽  
Vijul Shah ◽  
M.P. Shyam
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Elevated Temperatures ◽  
Rate Sensitivity ◽  
Superplastic Forming ◽  
Uniaxial Tensile ◽  
Sensitivity Index ◽  
Percentage Elongation ◽  
Strain Rate Sensitivity Index

Superplasticity is the ability of the material to produce neck free elongations within a material before fracture. For the past three decades superplastic forming has gained a major development in many industries to produce complex shapes. To perform the superplastic forming at elevated temperatures, the material parameters such as strain rate and strain rate sensitivity index has to be determined. These parameters affect the formability in such a way that higher the strain rate during deformation, lesser will be the percentage elongation and which in turn increases the flow stress of the material there by limiting the formability. Similarly, the strain rate sensitivity index is a measure of resistance to neck formation during deformation. Lesser the strain rate sensitivity value, more will be the neck formation thereby limiting the formability. Hence in this work, an experimental setup is designed to perform the uniaxial tensile testing at elevated temperatures to determine the flow stress, percentage elongation, strain rate and strain rate sensitivity. The determination of these parameters will be helpful in executing the forming at certain temperature and pressure to attain maximum formability. Also the SEM photographs of the fractured specimen were analysed to determine at what temperature and strain rate, the cavitation density increases.

Strength, Plasticity, Thermal Stability and Strain Rate Sensitivity of Nanograined Nickel with Amorphous Ceramic Grain Boundaries

2021 ◽  
pp. 116918
Author(s):  
Bingqiang Wei ◽  
Wenqian Wu ◽  
Dongyue Xie ◽  
Michael Nastasi ◽  
Jian Wang
Keyword(s):  
Thermal Stability ◽  
Strain Rate ◽  
Grain Boundaries ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity

scholarly journals Negative Strain Rate Sensitivity Induced by Structure Heterogeneity in Zr64.13Cu15.75Ni10.12Al10 Bulk Metallic Glass

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 339
Author(s):  
Xiang Wang ◽  
Zhi Qiang Ren ◽  
Wei Xiong ◽  
Si Nan Liu ◽  
Ying Liu ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Strain Rate ◽  
Bulk Metallic Glass ◽  
Strain Rate Sensitivity ◽  
Critical Role ◽  
Rate Sensitivity ◽  
Confined Compression ◽  
Negative Strain Rate Sensitivity ◽  
Cast Specimen ◽  
Structure Heterogeneity

The negative strain rate sensitivity (SRS) of metallic glasses is frequently observed. However, the physical essence involved is still not well understood. In the present work, small-angle X-ray scattering (SAXS) and high-resolution transmission electron microscopy (HRTEM) reveal the strong structure heterogeneity at nanometer and tens of nanometer scales, respectively, in bulk metallic glass (BMG) Zr64.13Cu15.75Ni10.12Al10 subjected to fully confined compression processing. A transition of SRS of stress, from 0.012 in the as-cast specimen to −0.005 in compression processed specimen, was observed through nanoindentation. A qualitative formulation clarifies the critical role of internal stress induced by structural heterogeneity in this transition. It reveals the physical origin of this negative SRS frequently reported in structurally heterogeneous BMG alloys and its composites.

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