The effect of the atomic incident angle upon the microstructure of thick beryllium deposits produced by physical vapor deposition

Thick (1–3 mm) beryllium deposits were produced by physical vapor deposition on a carbon‐coated polished 4130 steel substrate at 400 °C and with rates of deposition from 0.1 to 0.3 mm/h. The deposit microstructure was examined by metallographic technique and the characteristics of the growing as well as fracture surfaces by scanning electron microscopy. The texture of the deposits was determined by x‐ray diffraction and correlated with the deposition parameters. The deposits have unique grain and crystalline texture characteristics. They consist of columnar grains with their major axis parallel to the direction of incident adatoms. The self‐shadowing mechanism was not observed to have a prevalent contribution to the development of the microstructure during the growing process. The deposits were found also to be highly oriented with the major axis of their columnar grains, corresponding to the [001] crystallographic direction and always pointing toward the evaporation source. Within the range of deposition parameters that have been analyzed, the deposition rate was shown to have an insignificant effect upon the microstructure and texture characteristics of the deposits.