Semi-solid Twin-roll Casting Process of Magnesium Alloy Sheets

2004 ◽  
Author(s):  
H. Watari
Keyword(s):  
Magnesium Alloy ◽  
Casting Process ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Semi Solid ◽  
Twin Roll

Study on Molten Zone in Twin-Roll Casting of Magnesium Alloy Strip

2013 ◽  
Vol 395-396 ◽  
pp. 209-213
Author(s):  
Zhi Pu Pei ◽  
Hong Yang Zhao ◽  
Xiao Dong Hu ◽  
Dong Ying Ju
Keyword(s):  
Magnesium Alloy ◽  
Molten Pool ◽  
Casting Process ◽  
Solidification Structure ◽  
Molten Zone ◽  
Deformation Bands ◽  
Twin Roll Casting ◽  
Structure Changes ◽  
Roll Casting ◽  
Twin Roll

Thermal flow finite element simulation was carried out to deeply understand the solidification and deformation phenomena of magnesium alloy in molten zone during twin-roll casting process. The results show that temperature near the nip of the rolls is about 680K based on current conditions, and there are two vortexes in the molten pool during casting, a peak formed at solidus. Due to the metal flows in molten pool and relative rotates of the rolls, temperature field of molten zone is different from normal casting, which will cause the solidification structure changes. An experiment by using a vertical type twin-roll caster was also conducted, and the amount of deformation bands at the joint line is larger than that at the two sides. Substructures can be found due to dynamic recrystallization during casting process.

Thermal Flow-Solidification Simulation and Analysis of Strip Defects in Vertical Twin-Roll Casting of Magnesium Alloy

2015 ◽  
Vol 833 ◽  
pp. 15-18 ◽  
Author(s):  
Zhi Pu Pei ◽  
Dong Ying Ju ◽  
Hong Yang Zhao ◽  
Xiao Dong Hu
Keyword(s):  
Temperature Distribution ◽  
Magnesium Alloy ◽  
Casting Process ◽  
Thermal Flow ◽  
Twin Roll Casting ◽  
Solidification Simulation ◽  
Roll Casting ◽  
Pool Level ◽  
Cast Magnesium ◽  
Twin Roll

A quantitative understanding of the twin-roll casting process is required to get high quality as-cast magnesium alloy strips. In this paper, a thermal flow-solidification simulation was carried out to study the behavior of casting zone and its effects on defects generation deeply. Results show that a lower pouring temperature is not suitable for producing defect-free magnesium alloy strips. With increasing of the casting speed, the tendency of cracks formation will getting smaller because of the more uniform temperature distribution. A low pool level leads to a small metal-roll contact area, and a sharp temperature distribution will generates under this situation, which is not good for strips quality.

Numerical simulation of the twin-roll casting process of magnesium alloy strip

2009 ◽  
Vol 209 (5) ◽  
pp. 2321-2328 ◽  
Author(s):  
Jian Zeng ◽  
Roger Koitzsch ◽  
Herbert Pfeifer ◽  
Bernd Friedrich
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Casting Process ◽  
Alloy Strip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

scholarly journals Magnesium Alloy Strip Produced by a Melt-Conditioned Twin Roll Casting Process

2011 ◽  
Vol 690 ◽  
pp. 129-132 ◽  
Author(s):  
Iman Bayandorian ◽  
Yan Huang ◽  
Geoff M. Scamans ◽  
Zhong Yun Fan
Keyword(s):  
Magnesium Alloy ◽  
Tensile Elongation ◽  
Casting Process ◽  
Downstream Processing ◽  
Alloy Strip ◽  
Az91 Magnesium Alloy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Az91 Magnesium ◽  
Twin Roll

Melt conditioning by intensive shear was used prior to twin roll casting of an AZ91 magnesium alloy strip to promote heterogeneous nucleation and produce a refined and uniform microstructure without severe macro-segregation. The as-cast strip was then processed by homogenization, hot rolling and annealing and the microstructural behaviour during the downstream processing was examined and compared with the strip of the same alloy produced without melt conditioning. The melt conditioned strip after downstream processing displayed significantly improved mechanical properties with an average tensile elongation of ~16%, compared with ~10% for the strip produced without melt conditioning and the reported values of ~1.5-6.2% in the literature.

The Microstructure and Processing in Twin Roll Casting of Magnesium Alloy Strip

2005 ◽  
Vol 488-489 ◽  
pp. 427-430 ◽  
Author(s):  
Chun Mei Yang ◽  
Ding Fei Zhang ◽  
Pei Dao Ding ◽  
Fu Sheng Pan
Keyword(s):  
Magnesium Alloy ◽  
Casting Process ◽  
Strip Casting ◽  
Casting Temperature ◽  
Process Stability ◽  
Cast Strip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll ◽  
Cast Microstructure

Magnesium has a hexagonal close-packed crystal structure which makes it more difficult to deform than aluminum. Conventional strip production usually requires several process steps to reach the final strip thickness. Strip casting can reduce some of the process steps and make strip processing simpler and easier, especially for alloys with poor deformability. The twin-roll casting process can directly obtain strips with thickness less than one or two millimeters. In this paper, the metallurgical characteristics of the twin-roll strip casting process were analyzed and discussed. A laboratory scale vertical twin roll caster in prepared AZ31 magnesium alloy strips, with 1.0 to 2.0 mm thick and 150mm wide. Process stability in the thin strip casting process of the alloy has been studied, the casting temperature (superheat) was proven to be a key factor influencing process stability and casting strip quality. The as-cast microstructure of the alloy was analyzed and evaluated by optical microscopy, which showed that the as-cast microstructure was composed of developed dendrites when the superheat was high, and of a rosebush-like structure when the superheat was low. When the casting temperature was close to the liquid phase temperature，the as-cast microstructure became global or grainy, and the grain size of the cast strip was very small. This remarkably improved the deformability of the as-cast strip.

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