Mechanical Hardness as a Probe of Nanocrystalline Materials

1994 ◽  
Vol 362 ◽  
Author(s):  
C. C. Koch ◽  
T. D. Shen ◽  
T. Malow ◽  
O. Spaldon
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Grain Boundary ◽  
Nanocrystalline Materials ◽  
Size Dependence ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Softening Effect ◽  
Mechanical Hardness ◽  
Solid Solution Softening

AbstractThe use of mechanical hardness as a probe of nanocrystalline materials is reviewed. The fact that the grain size dependence of hardness is very different for nanocrystalline materials compared to conventional (≥1 μm diameter) polycrystals suggests a different deformation mechanism may be operative in nanocrystalline materials. Hardness is useful for following the sintering, densification reactions of nanoparticles. Solid solution hardening in nanocrystalline alloys is found to be overwhelmed by the grain boundary hardening. If alloying decreases the grain boundary hardening, i.e. increases grain size, an apparent solid solution softening effect is observed.

scholarly journals Microstructure and mechanical behavior of Al-xMg/5Al2O3 nanostructured composites

2022 ◽  
Author(s):  
Mehdi Delshad Chermahini ◽  
Ghorbanali Rafiei Chermahini ◽  
Jamal Safari
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Nanostructured Composite ◽  
Powder Particles ◽  
Mg Content

Abstract The effect of Mg content and milling time were investigated on the microstructure and microhardness values of Al-xMg/5Al2O3 (x = 0, 4, 8 and 12 wt %) nanostructured composite prepared via high energy milling technique. XRD results showed an acceleration of alloying process and formation of Al (Mg) ss by enhancing percentage of Mg element. Also, by increase in Mg percentage the grain size reduction was more considerable during milling treatment. Additionally, increment of the Mg content up to 12 wt%, causes the increase in micro-strain of the samples (from 0.31 to 0.82%). Increase in Mg concentration accelerates the mechanical milling process. According to SEM results a coaxial and circular morphology with a uniform distribution of powder particles has been formed. Up to 12 wt% (for each milling time), significant increase in microhardness (215 HV) was carried out due to solid solution hardening and crystallite refinement. From 10 to 15 h, a slight increase in microhardness up to 218 HV can be observed.

A Tem Study of Slip Systems in MoSi2/WSi2 Alloys

1991 ◽  
Vol 49 ◽  
pp. 942-943
Author(s):  
Stuart A. Maloy
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Slip Systems ◽  
High Melting ◽  
Group 14 ◽  
Solution Hardening ◽  
Brittle To Ductile Transition ◽  
High Melting Temperature ◽  
Tetragonal Unit Cell ◽  
Structural Applications

MoSi2 has recently been investigated as a potential material for high temperature structural applications. It has excellent oxidation resistance up to 1700°C, a high melting temperature, 2030°C, and a brittle-to-ductile transition temperature at 900-1000°C. WSi2 is isomorphous with MoSi2 and has a body-centered tetragonal unit cell of the space group 14/mmm. The lattice parameters are a=3.20 Å and c=7.84 Å for MoSi2 and a=3.21 Å and c=7.88 Å for WSi2. Therefore, WSi2 was added to MoSi2 to improve its strength via solid solution hardening. The purpose of this study was to investigate the slip systems in polycrystalline MoSi2/WSi2 alloys.

Solid solution hardening and softening in MoSi2 alloys

2001 ◽  
Vol 44 (6) ◽  
pp. 879-884 ◽  
Author(s):  
A.A Sharif ◽  
A Misra ◽  
J.J Petrovic ◽  
T.E Mitchell
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Hardening And Softening

Influence of grain boundary energy on the grain size evolution in nanocrystalline materials

2009 ◽  
Vol 475 (1-2) ◽  
pp. 893-897 ◽  
Author(s):  
Zheng Chen ◽  
Feng Liu ◽  
Wei Yang ◽  
Haifeng Wang ◽  
Gencang Yang ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Nanocrystalline Materials ◽  
Boundary Energy ◽  
Grain Boundary Energy ◽  
Size Evolution

Solid-solution hardening in b c c metals

1980 ◽  
Vol 15 (1) ◽  
pp. 253-254 ◽  
Author(s):  
M. Z. Butt ◽  
P. Feltham
Keyword(s):  
Solid Solution ◽  
Solid Solution Hardening ◽  
Solution Hardening
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