Effect of alloying elements and processing parameters on the Portevin-Le Chatelier effect of Al-Mg alloys

2015 ◽  
Vol 22 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Peng-cheng Ma ◽  
Di Zhang ◽  
Lin-zhong Zhuang ◽  
Ji-shan Zhang
Keyword(s):  
Processing Parameters ◽  
Mg Alloys ◽  
Alloying Elements ◽  
Chatelier Effect ◽  
Al Mg Alloys ◽  
Effect Of Alloying

scholarly journals Effect of alloying elements on the change of hydrogen content in Al-Mg alloys during annealing

2006 ◽  
Vol 56 (8) ◽  
pp. 423-428 ◽  
Author(s):  
Hidetoshi UMEDA ◽  
Goroh ITOH ◽  
Yoshinori KATO
Keyword(s):  
Hydrogen Content ◽  
Mg Alloys ◽  
Alloying Elements ◽  
Al Mg Alloys ◽  
Effect Of Alloying

Solute concentration dependence of strength and plastic instabilities in Al-Mg alloys

2005 ◽  
Vol 20 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Gy. Horváth ◽  
N.Q. Chinh ◽  
J. Lendvai
Keyword(s):  
Dislocation Line ◽  
Solute Concentration ◽  
Mg Alloys ◽  
Dynamic Strain ◽  
Solute Content ◽  
Serrated Flow ◽  
Indentation Tests ◽  
Power Law Function ◽  
Chatelier Effect ◽  
Al Mg Alloys

Characteristics of the dynamic strain aging (DSA) in the Portevin-Le Chatelier effect are experimentally investigated by dynamic indentation tests and numerically analyzed by using literature models. Experimental results obtained on Al–Mg alloys show that the occurrence and development of the plastic instabilities—serrated indentation—depend strongly on the solute content. During dynamic microindentation tests the amplitude of microhardness drops—similarly to the global hardness—and is changing as a power law function of Mg solute content with an exponent of 2/3. It has been shown that the term describing the effect of DSA in serrated flow is not proportional but rather a power expression of the local solute concentration, Cs, on the dislocation line with the exponent of 1/2. Together with this, the kinetics of solute segregation during DSA is controlled by the pipe diffusion.

scholarly journals Influence of precipitation on the Portevin-Le Chatelier effect in Al-Mg alloys

2011 ◽  
Vol 1 (1) ◽  
pp. 011007 ◽  
Author(s):  
Qi Hu ◽  
Qingchuan Zhang ◽  
Shihua Fu ◽  
Pengtao Cao ◽  
Ming Gong
Keyword(s):  
Mg Alloys ◽  
Chatelier Effect ◽  
Al Mg Alloys

scholarly journals Effect of Alloying Elements in Melt Spun Mg-alloys for Hydrogen Storage

2016 ◽  
Vol 19 (suppl 1) ◽  
pp. 20-26
Author(s):  
Silvia Rozenberg ◽  
Fabiana Saporiti ◽  
Julien Lang ◽  
Fernando Audebert ◽  
Pablo Botta ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Mg Alloys ◽  
Alloying Elements ◽  
Melt Spun ◽  
Effect Of Alloying

Microstructure Development in Powder Metallurgy Steels: Effect of Alloying Elements and Process Variables

2014 ◽  
Vol 782 ◽  
pp. 467-472 ◽  
Author(s):  
Eduard Hryha ◽  
Lars Nyborg
Keyword(s):  
Powder Metallurgy ◽  
Carbon Sources ◽  
Processing Parameters ◽  
Alloying Elements ◽  
Microstructure Formation ◽  
Prealloyed Powder ◽  
Conventional Sintering ◽  
The Difference ◽  
Characteristic Features ◽  
Effect Of Alloying

Microstructure of the powder metallurgy (PM) steels and especially mechanism of its formation differs significantly from the microstructure of the conventional steels even if composition will be exactly the same. The difference is not only connected to the presence of the pores, which are inalienable feature of the PM parts. Presence of the prior inter-particle boundaries, which can be contaminated by residual oxides, as well as microstructure heterogeneity are another characteristic features of the microstructure of PM steels. Microstructure heterogeneity is connected to the PM manufacturing process: powder mix, consisting of the base powder and additional alloying elements is compacted and then sintered. Fully prealloyed powder is not always possible to use in standard press & sintering route due to the solid solution strengthening of the ferrite resulting in bad powder compressibility. Hence, in order to provide good powder compressibility only pure iron or low-alloyed (typically <3 wt.%) powders are used. Required alloying elements and carbon (added as graphite) are further admixed in the powder form and are distributed during sintering by diffusion into iron particles at high temperatures. To assure satisfactory distribution of alloying elements, oxide layer, covering surface of the powder particles and hindering mass-transfer of the alloying elements, has to be removed first. This can be done by gaseous reducing agents as hydrogen and carbon monoxide. However, their cost and/or purity are of issue for modern alloyed PM steels. Admixed carbon, additionally to its function as alloying element, plays a role of effective reducing agent at higher temperatures. Paper summarizes the main features of microstructure formation during the whole sintering cycle (heating and isothermal sintering) and effect of alloying additives (different carbon sources, alloying elements) and processing parameters (sintering atmosphere composition, temperature profile) on the microstructure formation during conventional sintering process. Results indicate that for successful sintering of alloyed PM steels with homogeneous defect-free microstructure, hydrogen-rich atmospheres and high-temperature sintering are required.

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