2022 Fiscal Year Final Research Report
Formation mechanism of stair-like c-dislocation and development to the forest-dislocation hardening in magnesium alloys
Project/Area Number |
18K04755
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 26040:Structural materials and functional materials-related
|
Research Institution | Toyama Prefectural University |
Principal Investigator |
Suzuki Mayumi 富山県立大学, 工学部, 教授 (20292245)
|
Project Period (FY) |
2018-04-01 – 2023-03-31
|
Keywords | 林転位 / 非底面すべり / クリープ機構 / 転位再結合 |
Outline of Final Research Achievements |
The addition of rare earth elements is effective to improve high-temperature long-term (creep) strength of magnesium (Mg). However, the effect of solid solution hardening of rare earth elements is limited to the high-temperature range above the temperature range for practical use, and high alloying content that can introduce precipitates is required to achieve the strength at elevated temperatures for practical use. In this study, the strengthening effect of the forest c-dislocations introduced by plastic deformation in Mg-Y-based dilute solid solutions at temperatures below 0.5Tm (Tm: melting point) was investigated. The strengthening by the forest c-dislocations is limited to the very early stage of creep deformation and acts rather as a weakening factor on the long-time creep strength. The recombination mechanism of a- and c-dislocations at elevated temperatures was proposed as a possible factor.
|
Free Research Field |
材料強度学
|
Academic Significance and Societal Importance of the Research Achievements |
本研究課題の目的の一つである階段状林立c転位の導入起源を明らかにし,また,階段状c転位と可動a転位の再結合による非底面すべりの再活性化の可能性を見出すことができた.この結果は研究開始時には予想していなかったもので,当初目的に掲げていた林転位強化とは逆の方向(すなわち弱化)の効果をもたらす結果となったが,マグネシウムのような塑性加工が比較的困難な材料に対して転位の再結合を利用し,その加工性を改善できる可能性を得ることが出来た.
|