Project Fact Sheet 
REDUCTION OF ANNEALING TIMES 



 

	



	 
				
	 
		 
 				

 
	 
 	 	 


	 
 
	
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REDUCTION OF ANNEALING TIMES FOR ENERGY CONSERVATION 
Constituent 
Particles Recrystallized 
Grains 
Unrecrystallized 
Area 
IN ALUMINUM PROCESSING 
Aluminum strip, sheet, and plate products are produced by combinations of hot 
and cold rolling and annealing of large ingots. On the microstructure level, these 
products are composed of grains of aluminum. Grain size and orientation (texture) 
are very significant factors in controlling the strength, working, and forming 
properties of the final product. The mechanical forces involved in rolling change 
the original grain structure of the cast ingot. Annealing aluminum by heating to 
250-550oC and holding it at temperature restores the desirable properties. Many 
times, multiple annealing steps are necessary, which requires additional resources. 
Reducing or eliminating annealing steps will save energy and improve productivity. 
Annealing allows grain boundaries, size, and texture to reform and results in 
complex microstructural changes in aluminum. Most annealing is based on 
empirical experience. Annealing requirements vary significantly depending on the 
metal alloy and the amount of work performed by rolling. 
Project partners will study the kinetics of the annealing and rolling processes by 
making detailed measurements of the crystallographic and morphology of the 
internal structural changes. They will exploit new tools that are available for 
textural and microstructural characterization to measure recrystallization kinetics 
and texture evolution. A better understanding of these features will be 
incorporated into an annealing model. Better modeling will allow shorter annealing 
times. 


	
		 
Reduction of annealing times through study of recrystallization kinetics as a 
function of texture in hot deformation of alloys. 
OFFICE OF INDUSTRIAL TECHNOLOGIES 
ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY

	

 
Goals: The objective of this project is to provide new information on the kinetics 
of recrystallization in hot deformation. 
This research addresses the gap in the knowledge of how recrystallization in hot 
deformation depends on alloy type and crystallographic texture. The scope of the 
project covers characterization of recrystallization kinetics and mechanisms in 
the early stages of hot deformation of commercial aluminum alloys. Specific 
goals of this project include: 
• Developing automated method(s) for determining fraction recrystallized based 
on Orientation Imaging Microscopy (OIM) data sets. 
• Measuring fraction recrystallized as a function of annealing time for all major 
texture components based on hot deformation in the ingot breakdown phase. 
• Implementing texture-based computer simulation of recrystallization to provide 
a physical basis for the experimentally measured variation in recrystallization 
kinetics as a function of orientation. 
• Providing the data required by the industrial partner to construct a constitutive 
model for recrystallization in hot deformation (for ingot breakdown) that 
includes texture information. 







 
Year One 
• Conduct preliminary optical and scanning electron microscopy on alloys 1050 
and 5005 
• Complete preliminary hot deformation experiments on alloy 1050 
• Construct preliminary model of recrystallization kinetics 
• Complete recrystallization experiments on alloy 1050 
Year Two 
• Characterization of recrystallization kinetics on alloy 1050 
• Complete hot deformation experiments on alloy 5005 
• Develop analysis of recrystallization kinetics with model and OIM 
Year Three 
• Complete modeling of alloy 1050 
• Complete recrystallization experiments on alloy 5005 
• Conduct analysis of texture, recrystallization kinetics data 
• Transfer technology to modeling group 



 
The commercialization path is to take fundamental knowledge gained from 
research on kinetic recrystallization and transfer it to a wide cross-section of the 
thermomechanical industry through public papers and presentations. The 
industrial partner in the project will assist in the implementation of this technology 
from laboratory-scale experiments to industrial-scale hot deformation. 


	

 
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