Study on Microstructural Evolution of Deformed Magnesium Alloy during Partial Remelting

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.

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

Materials Science and Engineering A ◽

10.1016/j.msea.2008.12.042 ◽

2009 ◽

Vol 506 (1-2) ◽

pp. 8-15 ◽

Cited By ~ 44

Author(s):

Zude Zhao ◽

Qiang Chen ◽

Yanbin Wang ◽

Dayu Shu

Keyword(s):

Solid State ◽

Magnesium Alloy ◽

Microstructural Evolution ◽

Semi Solid

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Microstructure Evolution of Mg-6Zn-6Al Magnesium Alloy during Semi-Solid Partial Remelting

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.608 ◽

2011 ◽

Vol 306-307 ◽

pp. 608-612

Author(s):

Xiao Feng Huang ◽

K. Feng ◽

Y. Ma ◽

F.Y Yan ◽

Ti Jun Chen

Keyword(s):

Solid State ◽

Magnesium Alloy ◽

Shape Factor ◽

Solid Particles ◽

Dendritic Microstructure ◽

Partial Remelting ◽

Semi Solid ◽

Average Size ◽

Microstructure Of The Material ◽

Holding Temperature

A new magnesium alloy, named as Mg-6Zn-6Al(ZA66), using for thixoforming production has been developed. The microstructure of the material during partial remelting holding in the semi-solid state was characterized. The results indicate that non-dendrite microstructure in ZA66 magnesium alloy billets can be obtained, but the proper partial remelting temperature and holding time should be select. After being treated at 575°Cfor 20 min, the ZA66 alloys can obtain a non-dendritic microstructure with finer unmelted primary solid particles (37 μm) and shape factor about 0.6. With the increasing holding temperature from 575°C to 590°C,the average size of unmelted primary solid particles increases and globular tendency becomes more obvious.

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Microstructure Evolution of Deformed Magnesium Alloy in Semi-Solid State

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.313 ◽

2005 ◽

Vol 488-489 ◽

pp. 313-316

Author(s):

Sen Yuan ◽

Wu Xiao Wang ◽

Bai Ling Jiang

Keyword(s):

Solid State ◽

Magnesium Alloy ◽

Microstructure Evolution ◽

High Energy ◽

Mg Alloy ◽

Continuous Heating ◽

Heating Process ◽

Semisolid State ◽

Semi Solid ◽

Temperature Time

Magnesium alloy slurry was prepared using Strain-Induced Melt Activation(SIMA) technique. The samples were quenched into water so as to fix the high temperature instantaneous microstructures. The microstructure evolution of compressed deformation Mg alloy is studied in the process of continuous heating and iso-temperature of semi-solid state. The results indicate that deformed Mg alloy (AZ91) has first occurred to have the conversion of dendrite crystal-oriented isometric crystals in the continuous heating process. When the temperature rises to the range of semisolid state, the region with high energy at the pressed stripes begins to melt, showing that the cellular structures emerge in the crystal boundary and melting micro-pool phenomena appear within the crystals. With the iso-temperature time in semisolid state prolongs, the isometric crystals can be gradually converted into spherical crystal grains.

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Microstructural Evolution of SiCp/AZ61 Composites during Partial Remelting

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.141-143.545 ◽

2008 ◽

Vol 141-143 ◽

pp. 545-549 ◽

Cited By ~ 1

Author(s):

Hong Yan ◽

Fa Yun Zhang ◽

Wei Pan

Keyword(s):

Microstructural Evolution ◽

High Stability ◽

Isothermal Holding ◽

Holding Time ◽

Technological Parameters ◽

Partial Remelting ◽

Initial Stage ◽

Semi Solid

The microstructural evolution of SiCp/AZ61 composites during partial remelting was investigated. The results indicated that the suitable technological parameters of SiCp/AZ61 composites were the reheating temperature of 595°C ~ 600°C and isothermal holding time of 30min ~ 60min. The separation of microstructure of AZ61 matrix was faster than that of SiCp/AZ61 composites during the initial stage. In the meantime, SiCp/AZ61composites hold high stability during remelting process and a fine semi-solid thixoforming microstructure can be obtained with increases in temperature and holding time. In addition, the samples of SiCp/AZ61composites were susceptible to serious deformation and running out above 610°C.

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Study on Partial Remelting Microstructures and Mechanical Properties of ZK60-RE Magnesium Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.279 ◽

2006 ◽

Vol 116-117 ◽

pp. 279-283

Author(s):

Wei Wei Shan ◽

Zhi Ming Du ◽

Shou Jing Luo

Keyword(s):

Mechanical Properties ◽

Solid State ◽

Magnesium Alloy ◽

Magnesium Alloys ◽

Equal Channel Angular Extrusion ◽

High Strength ◽

High Quality ◽

Partial Remelting ◽

Semi Solid ◽

Re Elements

ZK60-RE is a kind of high strength magnesium alloy. Here, starting materials are casting ZK60-RE magnesium alloy and ZK60-RE magnesium alloy extruded by equal channel angular extrusion (ECAE), reheating to semi-solid state and studied on their partial remelting microstructures by means of microscope. The results show that ZK60-RE magnesium alloy extruded by ECAE are much finer and lead to the formation of spheroids quite rapidly while RE elements modified casting need a little longer time. At the same time, the mechanical properties of two kinds of ZK60-RE magnesium alloys are given. To do that, we want to find better magnesium alloys with high mechanical properties and good thixotropy, which adapt to semi-solid process to form the high quality complex component one time.

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Study on Nitridation Behavior of Mg-Ca Alloy under Nitrogen

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.415-417.1127 ◽

2011 ◽

Vol 415-417 ◽

pp. 1127-1131

Author(s):

Xiao Xia Yang ◽

Dun Qiang Tan ◽

Dong Fei Xiao ◽

Yi Jie Zhan

Keyword(s):

Magnesium Alloy ◽

Profile Analysis ◽

Surface Film ◽

Spray Forming ◽

Holding Time ◽

Mg Alloy ◽

Nitride Film ◽

Forming Process ◽

Small Cracks

To study the ignition-proof behavior in the spray deposited magnesium alloy with nitrogen as atomizing gas, SEM and XRD were employed to study the morphology and elements profile of nitride film formed on the Mg-5Ca alloy melt in different conditions, and the ignition proof principle was also analyzed preliminarily. The results indicated that under ordinary nitrogen (99.5%), a layer of smooth and continuous nitride film was formed on the surface of Mg-5Ca alloy after sintered at 740°C for 2 hours, and with the increasing of temperature and holding time, small cracks and cavities appeared locally on the surface film. The surface film was mainly composed of CaO、MgO、Ca3N2and Mg3N2.The profile analysis of the nitride film indicated that Ca element collected on the surface of the nitride film, and a multiple film was formed which filled the loose and holes of single film, avoided the burning of Mg alloy during spray forming process.

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