Microstructural evolution of an ECAE-formed ZK60-RE magnesium alloy in the semi-solid state

2009 ◽  
Vol 506 (1-2) ◽  
pp. 8-15 ◽  
Author(s):  
Zude Zhao ◽  
Qiang Chen ◽  
Yanbin Wang ◽  
Dayu Shu
Keyword(s):  
Solid State ◽  
Magnesium Alloy ◽  
Microstructural Evolution ◽  
Semi Solid

Study on Microstructural Evolution of Deformed Magnesium Alloy during Partial Remelting

2012 ◽  
Vol 192-193 ◽  
pp. 246-250 ◽  
Author(s):  
Qiang Chen ◽  
Gao Zhan Zhao ◽  
Da Yu Shu
Keyword(s):  
Solid State ◽  
Magnesium Alloy ◽  
Microstructural Evolution ◽  
Eutectic Phase ◽  
Holding Time ◽  
Mg Alloy ◽  
Liquid Droplets ◽  
Grain Coarsening ◽  
Partial Remelting ◽  
Semi Solid

Microstructural evolution of ZK60 Mg alloy during partial remelting was investigated in this paper. The results show that ZK60 Mg alloy semi-solid billets were successfully produced by recrystallisation and partial remelting (RAP) process. Following partial remelting in each case, grain coarsening had occurred in the semi-solid state with increasing holding time. Liquid was present, during partial remelting all four temperatures, in the form of isolated intragranular droplets. These liquid droplets were produced by intragranular eutectic phase and entrapped liquid. Intragranular liquid droplets migrated and merged into some large rounded liquid droplets. After the spheroidization was completed, coarsening and coalescence occurred. When temperature is relatively low (the thickness of liquid is relatively thin), grains contacted with each other, which produced irregular-shaped grains.

Casting in the Semi-Solid State of ZK60 Magnesium Alloy Modified with Rare Earth Addition

2014 ◽  
Vol 922 ◽  
pp. 694-699 ◽  
Author(s):  
E.P. Silva ◽  
Larissa Fernandes Batista ◽  
Bruna Callegari ◽  
Ivan Feierabend ◽  
Ricardo Henrique Buzolin ◽  
...  
Keyword(s):  
Solid State ◽  
Magnesium Alloy ◽  
Cast Alloy ◽  
Casting Process ◽  
Aged Alloy ◽  
Mechanical Agitation ◽  
Solution Treated ◽  
Homogeneous Chemical ◽  
Semi Solid ◽  
Zk60 Magnesium Alloy

In this work, the casting process under mechanical agitation in the semi-solid state was investigated for the production of ZK60 magnesium alloy modified with the addition of 2.5% wt ofmischmetal. The results show that this process enables the production of ingots with homogeneous chemical composition and free of shrinkage, inner defects and internal oxidation. The as-cast microstructure consists of an α-Mg matrix with globular grains reinforced by a grid of distinct intermetallics of Mg-Zn, Mg-Zn-RE and Mg-RE type along the grain boundaries. The yield strength at room temperature undergoes more than 50% increase during direct T5 aging, thus reaching 170 MPa. At 300°C, however, the dispersion of nanometric precipitates does not modify the hot deformation behavior of the aged alloy, which undergoes dynamic recrystallization in a similar manner to the as-cast alloy. DRX at 300°C is fastest for the alloy solution-treated at 500°C.

Effect of Disturbing Conditions in Semi-Solid State on Microstructure Evolution of Magnesium Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 296-299 ◽  
Author(s):  
Hong Jin Zhao ◽  
Yong Lin Kang ◽  
Zhao Hui Wang ◽  
Hai Liang Du
Keyword(s):  
Solid State ◽  
Magnesium Alloy ◽  
Microstructure Evolution ◽  
High Efficiency ◽  
External Disturbance ◽  
Dendritic Structure ◽  
Good Effect ◽  
Mechanical Stirring ◽  
Β Phase ◽  
Semi Solid

In this paper the microstructure evolution of AZ91HP magnesium alloy casts produced under different disturbing treatment conditions such as non-disturbing, argon blowing and mechanical stirring in semi-solid state after holding a short time was studied. The results show that the grains of AZ91HP alloy casts refined, the secondary dendritic arms grown and the dendrites tend to rosette shape with the decrease of holding temperature. External disturbance can accelerate the evolution process, and the spherical primary α phase formed easily under mechanical stirring treatment condition. The formation of non-dendritic structure is owing to ripening of the dendritic arms, refinement of the grains and movement of the primary formed solid phases. Disturbing treatments in semi-solid state induce more equilibrium solidification and decrease the amount of brittle β-Mg17Al12 phase. Blowing argon into the refined and modified magnesium alloy in semi-solid state can obtain homogeneous non-dendritic structure and the net shaped β phase distributed on α-Mg phase boundaries become fine and thin, this may be have a good effect on the mechanical properties of the magnesium alloy casts. Due to the low disturbing strength, argon blowing can maintain the metallurgy quality of the semi-solid slurry well, and also have high efficiency to make it. This technology need not new complex equipments and can be practiced in conventional casting conditions, so it may be used in industrialize manufacture.

Research on Thixoforging Magazine Plate of AZ91D Magnesium Alloy in Semi-Solid State

2006 ◽  
Vol 116-117 ◽  
pp. 267-270 ◽  
Author(s):  
Ju Fu Jiang ◽  
Shou Jing Luo
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Solid State ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Great Influence ◽  
Technological Parameters ◽  
Az91d Magnesium Alloy ◽  
Preheating Temperature ◽  
Semi Solid

The thixoforging process in which magazine plates of AZ91D magnesium alloy were thixoforged in semi-solid state using semi-solid billets prepared by common SIMA method and new SIMA method was investigated. The results show that the pressure has a great influence on the semi-solid billet’s ability to fill die’s cavity. When the pressure is 500KN, the semi-solid billet can’t fill the die’s cavity completely. When the pressure is 2000KN, the semi-solid billet can fill the die’s cavity completely. Room temperature mechanical properties, such as yield strength of 201.4MPa, ultimate tensile strength of 321.8MPa and elongation of 15.3%, can be obtained successfully when the technological parameters, including pressure of 200KN, die preheating temperature of 723K, holding for 20min at 818K, are satisfied. Comparing with common SIMA, mechanical properties of room temperature and high temperature at 373Kare enhanced heavily.

scholarly journals The microstructural evolution and hardness of the equiatomic CoCrCuFeNi high-entropy alloy in the semi-solid state

2018 ◽  
Vol 745 ◽  
pp. 75-83 ◽  
Author(s):  
L.J. Zhang ◽  
J.T. Fan ◽  
D.J. Liu ◽  
M.D. Zhang ◽  
P.F. Yu ◽  
...  
Keyword(s):  
Solid State ◽  
Microstructural Evolution ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Semi Solid
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