PHASE-CHANGE IN AL2AU INTERMETALLIC COMPO UND UNDER ELECTRON-IRRADIATION

Fine damage structure induced by electron irradiation in Al2Au was stu died with an electron microscope. Irradiation was done with 3.2044 x 1 0(-13) J (2 MeV) electrons at 170 K and room temperature using a high voltage electron microscope. Secondary defects such as dislocation loo ps are not formed at the irradiated region but a dotted structure deve lopped there. Unknown intensity distribution appears in the diffractio n pattern. It suggests that the fine structure is different from Al2Au . Taking the diffraction patterns and the X-ray spectra observed at th e different parts of the irradiated region into consideration, the cry stal phases formed by the irradiation were identified to be Al and AlA u. The orientation relationships between Al, AlAu and the matrix(Al2Au ) exist as the followings, [001](Al2Au)//[(1) over bar 11](AlAu)//[001 ](Al) and (010)(Al2Au)//(101)(AlAu)//(110)(Al) It was concluded that t he Au atoms diffuse towards the periphery of the irradiation area caus ed the phase change.