Precipitate Formation and Grain Refinement of MG-AL-SN Alloy during Hot Deformation

2012 ◽  
pp. 549-554
Author(s):  
Abu Syed Humaun Kabir ◽  
Jing Su ◽  
Phuong Vo ◽  
In-Ho Jung ◽  
Stephen Yue
Keyword(s):  
Grain Refinement ◽  
Hot Deformation ◽  
Precipitate Formation

scholarly journals Grain Refinement of a Powder Nickel-Base Superalloy Using Hot Deformation and Slow-Cooling

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1978 ◽  
Author(s):  
Xianqiang Fan ◽  
Zhipeng Guo ◽  
Xiaofeng Wang ◽  
Jie Yang ◽  
Jinwen Zou
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Hot Deformation ◽  
Nickel Base Superalloy ◽  
Polycrystalline Nickel ◽  
Slow Cooling ◽  
Homogeneous Microstructure ◽  
Average Grain Size ◽  
Nickel Base ◽  
Base Superalloy

A pre-hot-deformation process was applied for a polycrystalline nickel-base superalloy to active deformation twins and dislocations, and subsequent slow cooling treatment was used to achieve grain refinement and microstructure homogenization. The microstructural evolution of the alloy was investigated, and the corresponding underlying mechanism was discussed. It was found that twinning mainly occurred in large grains during pre-hot-deformation owing to the stress concentration surrounding the large grains. High density dislocations were found in large grains, and the dislocation density increased approaching the grain boundary. The average grain size was refined from 30 μm to 13 μm after slow cooling with a standard deviation of grain size decreasing from 10.8 to 2.8, indicating a homogeneous microstructure. The grain refinement and microstructure homogenization during cooling process could be achieved via (i) static recrystallization (SRX), (ii) interaction of twin tips and γ’ precipitates, and (iii) grain coarsening hindered by γ’ precipitates in grain boundaries.

Mechanism of grain refinement in an equiatomic medium-entropy alloy CrCoNi during hot deformation

2020 ◽  
Vol 815 ◽  
pp. 152382 ◽  
Author(s):  
Guoai He ◽  
Yifan Zhao ◽  
Bin Gan ◽  
Xiaofei Sheng ◽  
Yu Liu ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Hot Deformation

Hot deformation behaviour and grain refinement of intermetallic compound Ni3Al

1996 ◽  
Vol 60 (1-4) ◽  
pp. 575-580 ◽  
Author(s):  
I. Schindler ◽  
J. Machacek ◽  
J. Kliber ◽  
M. Greger ◽  
M. Kursa
Keyword(s):  
Intermetallic Compound ◽  
Grain Refinement ◽  
Hot Deformation ◽  
Deformation Behaviour ◽  
Hot Deformation Behaviour

Effect of Initial Grain Size on Deformation Behavior and Dynamic Recrystallization of Magnesium Alloy AZ31

2005 ◽  
Vol 488-489 ◽  
pp. 223-226 ◽  
Author(s):  
Xu Yue Yang ◽  
Masayoshi Sanada ◽  
Hiromi Miura ◽  
Taku Sakai
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
Hot Deformation ◽  
Structural Changes ◽  
Kink Bands ◽  
Alloy Az31 ◽  
Continuous Dynamic Recrystallization ◽  
Magnesium Alloy Az31 ◽  
Continuous Dynamic

Hot deformation and associated structural changes were studied in compression of a magnesium alloy AZ31 with initial grain sizes (D0) of 22 µm and 90 µm at a temperature of 573K. D0 influences significantly the flow curve and the kinetics of grain refinement during hot deformation. For D0 = 22 µm, grain fragmentation takes place due to frequent formation of kink bands initially at corrugated grain boundaries and then in grain interiors in low strain, followed by full development of new fine grains in high strain. For D0 = 90 µm, in contrast, twinning takes place in coarser original grains, and then kink bands and new fine grains are formed mainly in finer ones at low strains. Then new grains are formed in necklace along the boundaries of coarse original grains, followed by their development into the grain interiors. Grain refinement in the Mg alloy can be concluded to result from a series of deformation-induced continuous reactions, they are essentially similar to continuous dynamic recrystallization (cDRX).

Optimisation of Precipitation for the Development of Improved Wrought Fe3Al-based Alloys

2004 ◽  
Vol 842 ◽  
Author(s):  
Satoru Kobayashi ◽  
Stefan Zaefferer ◽  
André Schneider
Keyword(s):  
Grain Refinement ◽  
Hot Deformation ◽  
Single Phase ◽  
Fine Particles ◽  
Phase Region ◽  
Air Cooling ◽  
Two Phase ◽  
Kinetics Of ◽  
Very High ◽  
Grain Refinement Strengthening

ABSTRACTEffect of TiC precipitates on the kinetics of static recrystallisation has been studied by using a Fe-26Al-5Cr (at%) single-phase (α:A2/B2/D03) alloy and two-phase (α+TiC) alloys with different amounts of TiC precipitates. Based on the results, a desirable thermo-mechanical processing is proposed for the development of wrought Fe3Al-based alloys with strengthening MC carbides.In the alloys with a high amount of TiC, needle-like TiC precipitates with 1–10 μm in length formed during air-cooling after homogenisation. Hot deformations with such large precipitates cause inhomogeneous deformation around the particles, leading to particle stimulated nucleation (PSN) and hence accelerate recrystallisation.The occurrence of PSN is harmful for the embrittlement problem, i.e. ductility drastically decreases when recrystallisation occurs, but useful for grain refinement. The following process is proposed to accomplish grain refinement, strengthening by precipitates and avoidance of the embrittlement: hot deformation with a large amount of precipitates to make grain refinement possible by using PSN, followed by hot deformation with a small amount of precipitates near α single-phase region and a subsequent heat treatment to obtain fine precipitates. The fine particles would also act to pin the boundaries of growing grains, thus leading to extended recovery rather than recrystallisation. This process is difficult to carry out in the (Fe-26Al-5Cr)-TiC system because the temperature necessary to enable precipitation is very high and the kinetics is quick. The precipitation temperature is significantly decreased by replacing TiC by VC or MoC.

scholarly journals Microstructure evolution and grain refinement behavior during hot deformation of Fe micro-alloyed Ti-6Al-4V

2021 ◽  
Vol 15 ◽  
pp. 1881-1895
Author(s):  
Guoqing Dai ◽  
Jingzhe Niu ◽  
Yanhua Guo ◽  
Zhonggang Sun ◽  
Zhenhua Dan ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Microstructure Evolution ◽  
Hot Deformation
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