Sc含有Al-Mg合金及びAl-Mg-Si合金の高温疲労特性の評価と改善

フォーマット:

論文

責任表示:

渡邊, 千尋 ; Watanabe, Chihiro

言語:

日本語

出版情報:

金沢大学理工研究域機械工学系, 2010-05-12

著者名:

• 渡邊, 千尋
• Watanabe, Chihiro

掲載情報:

平成21(2009)年度 科学研究費補助金 若手研究(B) 研究成果報告書 = 2009 Fiscal Year Final Research Report

巻:

2007-2009

開始ページ:

4p.

バージョン:

author

概要:

Scを添加したAl-Mg合金及びAl-Mg-Si合金を作製し,高温における疲労挙動の調査を行った.その結果,Al-Mg合金においては,Al_3Sc粒子サイズが小さい場合には,運動転位による粒子のせん断が生じ疲労軟化を示し,粒子サイズが大きな場合には変形は均一となり疲労軟化は生じなかった.Al-Mg-Si合金においては,Scを添加する事で,・'-Mg_2Si析出物に加えてAl_3Sc粒子が析出し,このAl_3Sc粒子の存在により,変形の局在化を抑制し,疲労寿命が大きく … 改善する事を示した.<br />The effects of small amount of Sc addition on the fatigue properties of Al-Mg and Al-Mg-Si alloys at elevated temperatures have been examined. Cyclic softening after initial hardening is found in the Al-Mg alloys with small Al_3Sc particles, but no cyclic softening takes place in the alloys with larger particles. The cyclic softening is explained by a loss of particle strengthening through particle shearing within strongly strained slip bands. The larger Al_3Sc particles have a stronger retardation effect on the formation of fatigue-induced stable dislocation structure than small particles even at a high temperature. After peak-aging treatments, the Al-Mg-Si alloys has fine lath-shaped β' precipitates. In the Sc-containing Al-Mg-Si alloy, spherical Al_3Sc precipitates of about 11 nm in diameter are co-existed. The Al-Mg-Si alloy with Sc exhibits cyclic hardening to saturation, while the alloy without Sc shows clear cyclic softening after initial hardening. In the Sc-bearing Al-Mg-Si alloy, owing to the existence of non-shearable Al_3Sc precipitates, dislocations were uniformly distributed, resulting in the improvement of fatigue life. 続きを見る

URL:

http://hdl.handle.net/2297/00052191