Fabrication of Nonporous Layer on Surface of ALPORAS by Friction Stir Incremental Forming

Porous metals having nonporous (skin) layer at the surface have a potential to improve the mechanical properties of the porous metals. To fabricate nonporous layer on surface of porous metals, friction stir incremental forming process is applied to form surface of a commercial closed-cell type aluminum foam (ALPORAS) in this study. In the process, the cell walls near the surface of the aluminum foam are plastically deformed by a rotating tool with a high rotation rate, fabricated the nonporous layer at the surface. The nonporous layer with thinner than 0.4 mm is fabricated at the surface without internal fracture of the aluminum foam under forming conditions of a tool rotation rate of 8000 rpm, a tool feed rate of 60 mm/min, and total forming depth of 7.0 mm.8th International Conference on Porous Metals and Metallic Foams, Metfoam 201

Plastic joining of open-cell nickel foam and polymethyl methacrylate (PMMA) sheet by friction stir incremental forming

Matsumoto R., Sakaguchi H., Otsu M., et al. Plastic joining of open-cell nickel foam and polymethyl methacrylate (PMMA) sheet by friction stir incremental forming. Journal of Materials Processing Technology 282, 116691 (2020); https://doi.org/10.1016/j.jmatprotec.2020.116691.Friction stir incremental forming (FSIF) process was applied to join a commercial open-cell type nickel foam with a polymethyl methacrylate (PMMA) sheet for fabrication of porous metal–nonporous resin composite. In this process, a rotating rod-shaped tool was vertically pushed and horizontally fed against the sheet on the foam. The sheet was frictionally heated and incrementally deformed by the rotating tool, while the cellular matrix of the foam was not plastically deformed. The sheet with a thickness of 1.0 mm was joined with the foam under FSIF conditions of rotation rate faster than 2000 rpm and feed rate slower than 60 mm/min. The joining strength between the foam and the sheet was investigated by performing tensile test. The joining strength was obtained over the fracture strength of the foam. The joining mechanism of the foam and the sheet was discussed from the microscopic observation of the foam–sheet interface and the temperature change in the sheet. It is concluded that the sheet was mechanically interlocked (anchored) to the porous structure of the foam by the plastic flow of the heated and softened PMMA into the surface pores of the foam

Specific Strength of Sandwich-Structured Composite of Open-Cell Metallic Foam/Resin Joined by Friction Stir Incremental Forming

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1007/978-981-19-3307-3_31The compressive deformation behavior of an open-cell nickel foam joined with polymethyl methacrylate (PMMA) sheets by friction stir incremental forming (FSIF) process was investigated with uniaxial compression test. The sheet was joined on each side face of the foam for fabrication of the foam/sheet composite for uniaxial compression test. In FSIF process, the bottom of the sheet was mechanically interlocked to the surface pores of the foam by plastic flow of the frictionally heated sheet. In uniaxial compression test, the cubic foam/sheet composite was compressed with an initial strain rate of 1.0 × 10−3 s−1. The compressive specific strength of the foam/sheet composite was approximately 30 times higher than that of the foam. This was due to not only high specific strength of the sheet but also the sandwich structure of the foam/sheet composite

Fabrication of skin layer on aluminum foam surface by friction stir incremental forming and its mechanical properties

Matsumoto R., Tsuruoka H., Otsu M., et al. Fabrication of skin layer on aluminum foam surface by friction stir incremental forming and its mechanical properties. Journal of Materials Processing Technology 218, 23 (2015); https://doi.org/10.1016/j.jmatprotec.2014.11.030.Porous metals with a nonporous skin surface layer (sandwich structure) have a potential to improve their mechanical properties. Friction stir incremental forming process for sheet metals is applied to form the surface of a closed-cell type aluminum foam. In this process, the cell walls near the aluminum foam surface are plastically deformed and stirred by the rotation of a forming tool at a very high rate, and the nonporous skin layer is fabricated on the surface of the aluminum foam. Nonporous aluminum skin layer with a thickness less than 400 μm is fabricated at the surface without internal fracture of the aluminum foam under the following forming conditions; a tool rotation rate of 8000 rpm, a tool feed rate of 60 mm/min, and a total forming depth of 7 mm. To investigate the mechanism of formation of the skin layer, the skin layers fabricated with friction stir incremental forming and incremental hammering are compared. The compressive deformation behavior of aluminum foam with a skin surface layer is investigated by performing uniaxial compression test. The specific compressive strength of aluminum foam with a nonporous skin surface layer is improved by approximately 20-50%

DMO デザインと観光アメニティ開発戦略の適合仮説開発

The main purpose of this paper is to elaborate on DMO as one of the main themes in tourism studies and to provide a theoretical framework for measuring its performance. Measuring DMO’s performance refers to examining to what extent an area can be industrialized into a tourist spot. One of the conditions for the industrialization of tourist spot lies in its continuity. However, many of the existing DMO studies are limited to descriptions of the success of events, which are presumptuous when claiming such short-term cases as equivalent to the achievement of DMO. Instead, this paper focuses on the theoretical analysis of DMO and thus serves as a preparatory work for empirical research as well.We developed a model for matching DMO strategy formulation and its organizational structure to measure DMO performances. That is, DMO can determine two types of strategies according to the situations in which it is placed, and the appropriate organizational structure differs depending on the strategy adopted. In conclusion, this paper developed a hypothesis for further empirical research.論

工具回転機能を有したダイヤモンドチップバニシング加工の基礎的検討

金沢大学理工研究域機械工学系立方体形状の工作物の表面仕上げ法として，表面の平滑化，加工硬化ならびに圧縮残留応力の付与を目指したバニシング加工法について検討する．本加工法はフライス加工の要領で，先端に半球形状を有するダイヤモンドチップを高速で回転させながら，対象面上を定力下で摺動させる．本報では，高硬度材の平坦面に本加工法を適用した場合の基礎的な加工特性について，仕上げ面形状の観点から評価した結果を報告する．The effectiveness of a diamond burnishing method with rotating tool, which is proposed by the authors, is investigated. A proposed hybrid-type parallel mechanism with spherical 5-degree-of-freedom range and force control was used as a burnishing machine. A diamond tipped tool, which is rotated by the high-speeed-motor spindle, was used as a burnishing tool. A hardened die steel surface were targeted. The fundamental characteristics of the proposed method were evaluated by the surface profile and appearance of the burnishing mark and metallographic structure of the burnished surface layer, and the advantages of the proposed method were clarified by comparing with the conventional method, which is without the tool rotation.出版者照会後に全文公