2005 Fiscal Year Final Research Report Summary
Orientation control of Aluminum and Magnesium based alloys by the Viscous Motion of Dislocations
| Project/Area Number |
16560609
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Structural/Functional materials
|
|---|
| Research Institution | Yokohama National University |
|---|
Principal Investigator |
FUKUTOMI Hiroshi Yokohama National University, Department of Mechanical Engineering and Materials Science, Professor, 工学研究院, 教授 (90142265)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Keywords | dynamic recrystallization / preferred growth / texture / solute atomosphere dragging / non basal slip |
|---|
| Research Abstract |
In order to establish the basis for the texture control of aluminum and magnesium alloys by the viscous motion of dislocations, high temprature deformation and texture behaviors as well as microstructure change is investigated. Major results are summarized as follows. Uniaxial compression tests were conducted on Al-3mass%Mg alloy under various temperatures, amounts of strain and strain rates. High temperature yielding phenomena are seen at the temperatures higher than 623K and strain rates ranging from 1.0×10^<-3>s^<-1> to 1.0×10^<-4>s^<-1>. Texture examination elucidated that fiber textures are constructed in all the deformation conditions examined in this study. When the viscous motion of dislocation of the dominant deformation mechanism, the main component of fiber texture changes from {011} to {011}+{001} and to {001} with increase in strain and strain rate. It is considered that orientation stability against the lattice rotation by slip deformation as well as the rapid recovery du
… More
ring the deformation of the grains close to {001} orientation made it possible to grow by consuming the other deformed grains with the orientations such as {011}, resulting in the development of {001} texture in the former stage of deformation. In addition, it is attributed that {001} texture also developed bulging mechanism during occurrence of dynamicrecrystallization in the latter stage of deformation.
As for AZ31, the behaviors are investigated by uniaxial compression tests at temperatures, strain rates and final strains ranging from 573 to 773K, 1.0x10^<-3> to 5.0x10^<-5>s^<-1> and -0.2 to -1.5, respectively. Fiber texture is formed in all of the deformation conditions. The main component of the texture varies depending on deformation conditions ; it appears about 33°〜38° away from the basal pole after the deformation at higher temperatures and lower strain rates. This can be attributed to the increased activity of the secondary pyramidal slip system. With a decrease in temperatures and an increase in strain rate, the tilting angle of the main component (compression plane) from the basal pole decreases down to about 20°. Construction of a basal fiber texture was detected after deformations at the lowest temperature and high strain rates. Microstructure observations suggest that dynamic recrystallization occurs in most of the experimental conditions. Less
|
