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- Ghassemali, Ehsan, et al.
(författare)
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Optimization of axisymmetric open-die micro-forging/extrusion processes: An upper bound approach
- 2013
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Ingår i: International Journal of Mechanical Sciences. - : Elsevier BV. - 0020-7403 .- 1879-2162. ; 71, s. 58-67
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Tidskriftsartikel (refereegranskat)abstract
- There is a trend towards component miniaturization and strong drive towards cost effective and sustainable metal forming techniques of miniaturized components. This paper presents an upper bound solution for the optimization of open-die forging/extrusion processes in the forming of micro-pins from a sheet metal. Using such an analytical modeling approach, the critical blank thickness, the resulting final part geometry, together with the required forming load were predicted based on the location of the neutral plane under the punch during the process. Based on the phenomenological findings of the process, the geometry size factor, x, was introduced explaining its relative importance to the model. Experimental results obtained from C11000 copper samples using a progressive microforming process was found to agree well with the results predicted by the model. The results were also validated with other results reported before from a similar process.
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| 2. |
- Wang, Yongsheng, et al.
(författare)
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Corrosion Behavior and Surface Analysis of Melt-spun Mg-based Metallic Glass in Physiological Saline Solution
- 2012
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Ingår i: Materials Science Forum. - Switzerland : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 706-709, s. 606-611
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Tidskriftsartikel (refereegranskat)abstract
- The developed Mg-based metallic glass shows great potential as implants in biomedicalapplications instead of crystalline Mg alloys, which may possesses acceptable corrosion properties. Inthis study, corrosion behaviors of melt-spun amorphous Mg67Zn28Ca5 ribbons were investigated inphysiological saline solution. Electrochemical testing and hydrogen evolution rate indicated that theglassy ribbons obtained at lower wheel speed were more noble with smaller corrosion current, andpossessed a comparatively lower corrosion rate in physiological saline solution. Surface morphologyanalysis revealed that glassy Mg67Zn28Ca5 ribbons exhibited a strong susceptibility to localizedpitting corrosion. A Zn-rich passive layer was formed on the surfaces of the glassy ribbons, indicatingthat Zn was an effective alloying element to enhance the corrosion resistance of amorphousMg67Zn28Ca5 alloys.
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