Abstract
Investigations have been made on the epitaxial growth of columnar grains in niobium and aluminum weld metals, and also on the crystallographic properties of dendrites developed in the weld crater. Conclusions obtained are as follows:
(1) It was confirmed by X-ray diffraction method that the columnar grains grew epitaxially in the weld metal.
(2) The weld metal in an aluminum single crystal grew in the same crystallographic direction as the original single crystal.
(3) A columnar grain had a single crystallographic direction, whereas the direction of growth changed gradually.
(4) Dendrites were observed in the weld craters of many metals. It was found that the dendrites in niobium weld metal grew in the direction of ‹100› regardless of the welding speed.
