Prediction of Development of Inhomogeneous Plastic Deformation and Fracture Based on Change in Elastic Height Distribution in Polycrystalline Metals

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01337
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Okayama University
• Principal Investigator: Tada Naoya 岡山大学, 自然科学研究科, 教授 (70243053)
• Co-Investigator(Kenkyū-buntansha): 上森 武 岡山大学, 自然科学研究科, 准教授 (70335701) ; 坂本 惇司 岡山大学, 自然科学研究科, 助教 (50752052)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 弾性不均一変形 / 塑性不均一変形 / 表面高度分布 / 多結晶金属材料 / 表面あれ

Outline of Final Research Achievements

Tensile tests were carried out using plate and thin sheet specimens of polycrystalline pure titanium. Microscopic inhomogeneous deformations under elastic and plastic conditions were discussed focusing on the deformation of thin sheet specimens where the effect of interior crystal grains was week. The following resutls were obtained. Height changes at the center of grains were correlated with those near the grain boundaries. Correlation between the height changes on the front and back surfaces changed when the deformation changed from elastic to plastic. The initiation of slip lines near the notch could be predicted by slip activity.

Free Research Field

固体力学

Academic Significance and Societal Importance of the Research Achievements

本研究では純チタンの微視的不均一変形を変形初期に相当する弾性状態から塑性状態まで詳細に観察・測定し，弾性不均一変形と塑性不均一変形の関係等を明らかにした．本材料では，塑性不均一変形が主としてすべりによって生じるが，切欠き材のような応力集中部が存在する場合を含め，すべり線の発生を予測する手法を提案した．すべりの発生予測や弾性不均一変形と塑性不均一変形の関係は，材料の破壊と深く関連するため，各種構造材料の破壊防止に有用であると考える．