1 0 0 0 OA 強加工により結晶粒を微細化したアルミニウムの耐孔食性
- 著者
- 孫 仁俊 中野 博昭 大上 悟 小林 繁夫 福島 久哲 堀田 善治
- 出版者
- 公益社団法人 日本金属学会
- 雑誌
- 日本金属学会誌 (ISSN:00214876)
- 巻号頁・発行日
- vol.69, no.10, pp.892-898, 2005 (Released:2005-10-20)
- 参考文献数
- 13
- 被引用文献数
- 12 13
The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl- and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were evidently shifted to the noble direction by ECAP process, indicating that this process improves resistance to pitting corrosion. SEM observation revealed that the pitting corrosion occurred near the impurity precipitates and the size of impurity precipitated decreased with ECAP process. The time-dependence of corrosion potential and the polarization resistance determined by AC impedance technique suggested that the formation rate of Al oxide films was increased with ECAP process. The improvement in pitting corrosion resistance of Al and Al-Mg by ECAP seems to be attributable to the decrease in the size of impurity precipitates and the increase in the formation rate of Al oxide films.
1 0 0 0 OA 高圧スライド(HPS)加工で結晶粒微細化したA2024合金板材の超高強度化と超塑性の発現
- 著者
- 増田 高大 瀧沢 陽一 湯本 学 小田切 吉治 堀田 善治
- 出版者
- 公益社団法人 日本金属学会
- 雑誌
- 日本金属学会誌 (ISSN:00214876)
- 巻号頁・発行日
- vol.80, no.9, pp.593-601, 2016 (Released:2016-08-25)
- 参考文献数
- 40
- 被引用文献数
- 2 7
In this study, the method of high-pressure sliding (HPS) was applied for grain refinement of an A2024 alloy. Sheet samples with 10-15 mm width and 100 mm length with 1 mm thickness were processed by HPS under pressures of 2-3 GPa. Microstructural observations revealed that the grain size was refined to ~200 nm. Tensile tests showed that the ultimate tensile strength reached 886 MPa with a total elongation of 7.1% and the anisotropy of samples was less developed in the HPS-processed samples. Extra strengthening was attained by aging at 423 K after HPS processing, leading to an ultimate tensile strength of 967 MPa at the peak aged condition. Superplastic elongation of more than 400% appeared when the A2024 alloy processed by HPS for 20 mm was deformed in tension at a testing temperature of 623 K with an initial strain rate of 1.0×10−3 s−1.