Development of torsion and back-torsion process to minimize bending radius of magnesium pipe

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06868
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Tokyo University of Technology
• Principal Investigator: FURUI Mitsuaki 東京工科大学, 工学部, 教授 (90262972)
• Co-Investigator(Kenkyū-buntansha): 會田 哲夫 富山大学, 学術研究部都市デザイン学系, 教授 (20283062)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: ねじり・ねじり戻し加工 / 引張・圧縮降伏応力比 / 結晶方位ランダム化

Outline of Final Research Achievements

It was clarified that the tensile-compression yield stress ratios of magnesium alloys were almost equal by applying 0.25 unidirectional shear strain. It was confirmed that the peak strength of magnesium (0002) plane decreased and the non-basal plane slip such as prismatic plane (1010) and pyramidal plane (1011) became active as the torsion angle increased. When the shear strain exceeds 0.27, bending without cracking or crushing can be performed. These research results promote the application of lightweight magnesium to transportation equipment such as automobiles and aircraft. It was also shown that magnesium is usually plastically worked in the warm region, can be performed at room temperature by processes such as torsion and back-torsion that improve the crystal structure.

Free Research Field

材料加工

Academic Significance and Societal Importance of the Research Achievements

環境調和性が高いプロセス制御型の材料加工研究の一環として実施した本研究の成果は、自動車や航空機など輸送機器へ軽量なマグネシウム部材の適用を促進するものであり、それにより燃費の大幅な低減が期待される。また、通常は温間領域で塑性加工されるマグネシウムのような難加工材料も、ねじり・ねじり戻しのような組織と構造を改善するプロセスによって、室温における製品の成形加工が可能であることを示した。