純金属の高温硬さと硬さクリープ特性
1987 年 73 巻 9 号 p. 1186-1192
詳細
1987 年 73 巻 9 号 p. 1186-1192
In this study, eighteen kinds of polycrystalline pure metals were provided to investigate the hot-hardness and the indentation creep characteristics at elevated temperatures.
The inflection temperatures where the hot-hardness started to decrease quickly with increasing temperature were observed in the range from 0.35 to 0.68 Tm (where Tm was melting point on the absolute scale), and were calculated as 0.49 Tm on the average.
However, in some semi-conductor metals such as Si or Ge, the second inflection temperature appeared.
The slope of the plot of logHV-logt (t was indentation creep time in sec.) which was defined as "indentation creep rate" was the largest in Mo and the smallest in Si at 0.60 Tm. There was a tendency for the indentation creep rate to increase linearly with increasing homologous temperature, and the slope of the line was the largest in bcc and it became smaller with fcc and cph systems.
On the other hand, in the case of semiconductors the indentation creep rate decreased with increasing temperature up to the second inflection temperature.
The activation energies of pure metals calculated from the indentation creep were close to those for selfdiffusion.
