The role of matrix dislocations in the superplastic deformation of a copper alloy

1986 ◽  
Vol 34 (7) ◽  
pp. 1203-1214 ◽  
Author(s):  
L.K.L. Falk ◽  
P.R. Howell ◽  
G.L. Dunlop ◽  
T.G. Langdon
2007 ◽  
Vol 48 (560) ◽  
pp. 787-792
Author(s):  
Masafumi NODA ◽  
Hisashi MORI

1990 ◽  
Vol 196 ◽  
Author(s):  
Yan Ma ◽  
Terence G. Langdon

ABSTRACTIt is well known that cavities are nucleated and grow during the superplastic deformation of many materials. The various theories for cavity growth are examined with special emphasis on the role of growth by diffusion. It is demonstrated that the normal model for the diffusion growth of cavities is inadequate for superplastic materials when the grain boundary lengths are very small. By developing a new model for the growth of an isolated cavity to sizes exceeding the grain size, it is shown that the diffusion process may play a major role in cavity growth under a range of experimental conditions.


2015 ◽  
Vol 81 ◽  
pp. 311-341 ◽  
Author(s):  
Jonathan A. Horn

Iron Age tankards are stave-built wooden vessels completely covered or bound in copper-alloy sheet. The distinctive copper-alloy handles of these vessels frequently display intricate ‘Celtic’ or La Tène art styles. They are characterised by their often highly original designs, complex manufacturing processes, and variety of find contexts. No systematic analysis of this artefact class has been undertaken since Corcoran’s (1952a) original study was published in Volume 18 of these Proceedings. New evidence from the Portable Antiquities Scheme for England and Wales and recent excavations have more than quadrupled the number of known examples (139 currently). It is therefore necessary and timely to re-examine tankards, and to reintegrate them into current debates surrounding material culture in later prehistory. Tankards originate in the later Iron Age and their use continued throughout much of the Roman period. As such, their design was subject to varying influences over time, both social and aesthetic. Their often highly individual form and decoration is testament to this fact and has created challenges in developing a workable typology (Corcoran 1952a; 1952b; 1957; Spratling 1972; Jackson 1990). A full examination of the decoration, construction, wear and repair, dating, and deposition contexts will allow for a reassessment of the role of tankards within the social and cultural milieu of later prehistoric and early Roman Britain.


2021 ◽  
Vol 146 ◽  
pp. 103108
Author(s):  
Min Zha ◽  
Hongmin Zhang ◽  
Hailong Jia ◽  
Yipeng Gao ◽  
Shenbao Jin ◽  
...  

1990 ◽  
Vol 196 ◽  
Author(s):  
T. R. Parayil ◽  
G. L. Dunlop ◽  
P. R. Howell

ABSTRACTTransmission electron microscopy (TEM) has been employed to examine the role of dislocations in the superplastic deformation of a duplex stainless steel. In particular, matrix, grain boundary and interphase interface dislocation distributions have been documented after testing in region II. It is concluded that dislocation activity is of importance during superplastic flow and both loop sources and dislocation pile-ups have been observed. The presence of highly distorted dislocation arrays also suggests that grain and interphase boundary sliding is intimately linked to the motion of grain and interphase boundary dislocations. Finally, it is argued that dislocation multiplication in interphase interfaces can involve the operation of loop sources.


2015 ◽  
Vol 7 (4) ◽  
pp. 2310-2321 ◽  
Author(s):  
Abdel-Aziz El Mel ◽  
Farah Boukli-Hacene ◽  
Leopoldo Molina-Luna ◽  
Nicolas Bouts ◽  
Adrien Chauvin ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document