Guide for material design in strengthening and toughening of biodegradable magnesium alloy through heterogeneous distribution of solute near grain boundary

2015 Fiscal Year Final Research Report

• Project/Area Number: 25246012
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanomaterials engineering
• Research Institution: Kobe University
• Principal Investigator: MUKAI TOSHIJI 神戸大学, 自然科学系先端融合研究環, 教授 (40254429)
• Co-Investigator(Kenkyū-buntansha): SHIMIZU Yoshinaka 東北大学, 歯学研究科, 助教 (30302152) ; YAMAGUCHI Masatake 日本原子力研究開発機構, システム計算科学センター, 研究主幹 (50360417) ; SINGH Alok 物質・材料研究機構, 元素戦略材料センター, 主席研究員 (60354213) ; IKEO Naoko 神戸大学, 工学研究科, 助教 (80647644)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: ヘテロ・ホモ構造 / 粒界凝集エネルギー / 結晶粒微細化 / 溶質原子 / 共偏析 / 高強度化 / 高靱性化 / 生体内分解性

Outline of Final Research Achievements

To develop a biodegradable magnesium alloy exhibiting high strength with toughness and/or ductility, the generalized stacking fault energy and grain boundary cohesive energy were estimated by the first-principles calculations. On one hand, evaluated impact toughness suggested that addition of Ca along with Zn or Al reduced plastic anisotropy and strengthened the grain boundaries, leading to higher in impact toughness of Mg alloys. Biocompatibility of the alloy was confirmed by investigating its degradation behavior and the response of extraperitoneal tissue around the ternary alloy. The Mg-Zn-Ca alloy clip successfully occluded the renal vein, and nail penetrated the skull. Little gas generation was observed following implantation of the developed Mg-Zn-Ca clip or nail by in vivo micro-CT. Histological analysis, minimal observed inflammation, and an only small decrease in the volume of the implanted Mg-Zn-Ca clip confirmed its excellent biocompatibility.

Free Research Field

機械材料学