抄録
Test pieces of large grains of aluminium and iron were made and they were subjected to tensile deformation at the o-dinary temperature and at elevated temperatures as high as the melting point of aluminium and the transformation point of alpha iron into gamma iron. Changes of elongation from point to point were obtained by measuring mean values between gauge length of two millimeters. It was found that the hardness in the vicinity of the grain boundary is always different from that within the grain, which varies also with the direction of tension relative to the crystal axis. Possible explanations of the structure of grain boundary are discussed.
