抄録
It is well-known that viscosity is quite important as a “structure sensitive” property to investigate the structure of liquid metals and alloys. For the curpcse of obtaining some knowledges on the structure of liquid iron and nickel, viscosity was precisely measured on these metals in the temperatures between 1490 and 1700° and 1466 and 1665° respectively, by means of oscillating crucible method.
From the results of this measurement, it was found that the viscosity coefficient of liquid iron discontinuosly changed in the temperature range between 1580 and 1640°, and activation energies for viscous flow were 11·0 and 6·9 kcal/ mol at the temperaturesab ove 1640° and below 1580°, respectively. These facts indicate that certain structural change occurs in liquid iron at the temperatures corresponding to the discontinuous change of viscosity. This structural change may be well explained to be the break down of bcc-like short range order presumably existing at the lower temperatures and subsequent increase of randomness of atomic distribution. On the other hand, such a structural change in liquid nickel was not recognized in the range of experimental temperature between 1466 and 1665°.
