In order to clarify the problems involved in the measurement of the threshold stress for high-temperature deformation in a dispersion-strengthened alloy, using an Al-1.5 vol% Be alloy in which the strengthening mechanism has been identified, the threshold stress was measured by four different techniques: tensile test, stress relaxation test, creep test and stress abruptly loading test. The measured values were compared with the Orowan stress and the void-hardening stress calculated from dispersion parameters. The yield stress obtained from the tensile test at room temperature was higher than the Orowan stress: the proportional limit was about 1.3 times and the 0.2% proof stress was about 3 times. For the stress relaxation test, no clear zero-creep stress was observed at high temperatures and the approximately determined zero-creep stress strongly depended on temperature, decreasing as temperature rose. The threshold stress obtained from the creep test agreed approximately with the void-hardening stress of the slightly higher Orowan stress than the void-hardening stress. The threshold stress at high temperatures, 623 and 673 K, obtained from the stress abruptly loading test decreased from the Orowan stress to the void-hardening stress as the time elapsed under load. From these results, the problems in the measurement of threshold stress are discussed and the stress abruptly loading technique is recommended.
|ジャーナル||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|出版ステータス||出版済み - 1994|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry