Restoration of the fatigue limit of structural elements made of aluminum alloys by surface strain-hardening

1989 ◽  
Vol 21 (8) ◽  
pp. 981-985
Author(s):  
M. N. Stepnov ◽  
S. P. Evstratova ◽  
V. V. Logvinenko ◽  
V. V. Mozalev
Keyword(s):  
Aluminum Alloys ◽  
Strain Hardening ◽  
Fatigue Limit ◽  
Surface Strain ◽  
Structural Elements

Sensitivity Analysis of the Material Flow Stress in Machining

Manufacturing ◽  
2003 ◽  
Author(s):  
Ning Fang
Keyword(s):  
Sensitivity Analysis ◽  
Flow Stress ◽  
Aluminum Alloys ◽  
Strain Rate ◽  
Strain Hardening ◽  
Material Flow ◽  
Chemical Compositions ◽  
Wide Range ◽  
Strain Rate Hardening ◽  
Factor Governing

Among the effects of strain hardening, strain-rate hardening, and temperature softening, it has long been argued about which effect is predominant in governing the material flow stress in machining. This paper compares four material constitutive models commonly employed, including Johnson-Cook’s model, Oxley’s model, Zerilli-Armstrong’s model, and Maekawa et al.’s model. A new quantitative sensitivity analysis of the material flow stress is performed based on Johnson-Cook’s model covering a wide range of engineering materials, including plain carbon steels with different carbon contents, alloyed steels, aluminum alloys with different chemical compositions and heat treatment conditions, copper and copper alloys, iron, nickel, tungsten alloys, etc. It is demonstrated that the first predominant factor governing the material flow stress is either strain hardening or thermal softening, depending on the specific work material employed and the varying range of temperatures. Strain-rate hardening is the least important factor governing the material flow stress, especially when machining aluminum alloys.

Interrogations on the sub-surface strain hardening of grit blasted Ti–6Al–4V alloy

2009 ◽  
Vol 203 (14) ◽  
pp. 2036-2040 ◽  
Author(s):  
M. Multigner ◽  
E. Frutos ◽  
C.L. Mera ◽  
J. Chao ◽  
J.L. González-Carrasco
Keyword(s):  
Strain Hardening ◽  
Surface Strain

Experimental Test of Reinforcing a Masonry Column with Fiber Reinforced Strain Hardening Cementitious Composite

2015 ◽  
Vol 752-753 ◽  
pp. 568-571
Author(s):  
Marek Jašek ◽  
Jan Hurta ◽  
Jiri Brozovsky
Keyword(s):  
Strain Hardening ◽  
Experimental Test ◽  
Industrial Waste ◽  
Structural Elements ◽  
Cementitious Composite ◽  
Fiber Reinforced ◽  
Innovative Materials ◽  
Construction Practice

In construction practice, we often encounter a situation where there is overloading of the existing columns and pillars, namely due to various adaptations and extensions. Masonry columns and pillars are usually loaded with vertical forces. Overloading these structural elements leads to the crushing of masonry. To prevent the destruction of columns and pillars it is often proposed to reinforce these elements.The paper deals with the possibilities of using new innovative materials in the reinforcement of masonry columns, namely a "green" fiber cementitious composite with the so-called "strain hardening", which uses industrial waste mainly from the Moravian-Silesian Region.

scholarly journals Investigation of the Effect of End Mill-Geometry on Roughness and Surface Strain-Hardening of Aluminum Alloy AA6082

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3078
Author(s):  
Pavel Filippov ◽  
Michael Kaufeld ◽  
Martin Ebner ◽  
Ursula Koch
Keyword(s):  
Surface Roughness ◽  
Strain Hardening ◽  
Cutting Edge ◽  
Surface Strain ◽  
Micro Milling ◽  
End Mill ◽  
Cutting Edge Radius ◽  
Hardened Zone ◽  
Edge Radius ◽  
Machined Surfaces

Micro-milling is a promising technology for micro-manufacturing of high-tech components. A deep understanding of the micro-milling process is necessary since a simple downscaling from conventional milling is impossible. In this study, the effect of the mill geometry and feed per tooth on roughness and indentation hardness of micro-machined AA6082 surfaces is analyzed. A solid carbide (SC) single-tooth end-mill (cutting edge radius 670 nm) is compared to a monocrystalline diamond (MD) end-mill (cutting edge radius 17 nm). Feed per tooth was varied by 3 μm, 8 μm and 14 μm. The machined surface roughness was analyzed microscopically, while surface strain-hardening was determined using an indentation procedure with multiple partial unload cycles. No significant feed per tooth influence on surface roughness or mechanical properties was observed within the chosen range. Tools’ cutting edge roughness is demonstrated to be the main factor influencing the surface roughness. The SC-tool machined surfaces had an average Rq = 119 nm, while the MD-tool machined surfaces reached Rq = 26 nm. Surface strain-hardening is influenced mainly by the cutting edge radius (size-effect). For surfaces produced with the SC-tool, depth of the strain-hardened zone is higher than 200 nm and the hardness increases up to 160% compared to bulk. MD-tool produced a thinner strain-hardened zone of max. 60 nm while the hardness increased up to 125% at the surface. These findings are especially important for the high-precision manufacturing of measurement technology modules for the terahertz range.

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