TEM and computer image simulation studies on the dissociation of superdislocations in L1{sub 2} Al{sub 3}Ti alloy

TEM investigation associated with computer image simulations were conducted to determine the dislocation core structure in the L1{sub 2} Al{sub 67}Mn{sub 8}Ti{sub 25} alloy deformed at room temperature. It is identified that the a{l_angle}110{r_angle} superdislocations dissociated into pairs of a/3{l_angle}112{r_angle} superpartials with SISF between them. The theoretical and experimental micrographs are in good agreement under various diffraction conditions. The unusual temperature dependence of flow stress at low temperature can be related to the SISF-type dissociation.

[1]  W. W. Milligan,et al.  Identification of partial dislocations and faults in cubic Al_3Ti , 1994 .

[2]  M. Mills,et al.  Measurements of antiphase boundary and complex stacking fault energies in binary and B-doped Ni3Al using TEM , 1993 .

[3]  Y. Rong,et al.  Dissociation of dislocations in Al67Mn8Ti26 deformed at ambient and high temperatures , 1993 .

[4]  R. Schäublin,et al.  A method for simulating electron microscope dislocation images , 1993 .

[5]  D. G. Morris,et al.  Comment on ‘Transmission electron microscopy of dislocation structures in iron-doped Al3Ti with the L12 structure’ , 1993 .

[6]  Shipu Chen,et al.  Ductility improvement on Al67Ti25Mn8 intermetallic alloy via hot-working , 1992 .

[7]  D. G. Morris.  Dislocations in plastically deformed L1_2 compounds based on Al_3Ti , 1992 .

[8]  S. Brown,et al.  Tensile deformation of the forged L12 compound Al66Ti25Mn9 , 1992 .

[9]  D. G. Morris,et al.  PLASTIC DEFORMATION OF AN IRON-MODIFIED TITANIUM TRIALUMINIDE ALLOY , 1991 .

[10]  Hu Gengxiang,et al.  Plastic deformation and fracture behavior of a Fe-modified Al_3Ti-base L1_2 intermetallic alloy , 1991 .

[11]  E. George,et al.  Brittle cleavage of L1_2 trialuminides , 1990 .

[12]  J. Wert,et al.  Microstructure, deformation and fracture characteristics of an Al67Ni8Ti25 intermetallic alloy , 1989 .

[13]  G. Ackland,et al.  HIGH-TEMPERATURE ORDERED INTERMETALLIC ALLOYS III , 1989 .

[14]  D. Pope.  High Temperature Ordered Intermetallic Alloys , 1986 .

[15]  W. Drabik,et al.  On the Analytical Methods of Line Defect and Beam Direction Determinations , 1983, June 16.