High quality dissimilar joining using stress relaxation insert layer of porous structure with low thermal expansion fabricated by metal additive manufacturing

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06097
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Production engineering/Processing studies
• Research Institution: Kindai University
• Principal Investigator: Ikeshoji Toshi-Taka 近畿大学, 次世代基盤技術研究所, 特任准教授 (40302939)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 付加製造 / パウダーベッド / ニッケル基合金 / 異材接合 / 熱膨張係数

Outline of Final Research Achievements

A dissimilar material joint between a Ni-based alloy and a C/C composites was obtained using a Ni-based brazing filler alloy by inserting a porous interlayer fabricated by the laser powder bed fusion (PBF-LB), which was expected to relief the residual stress. In the course of the research, a numerical calculation method was developed to simulate the PBF-LB process considering the melt solidification phenomenon in order to confirm the modeling accuracy possible with PBF-LB, and the minimum thickness was estimated to be about twice the laser spot diameter. The CTE value of Ni-based brazing material was measured in the range of 100-1100 °C to obtain basic data for brazing joint strength prediction. It was also clarified that the change in the powder bed temperature during the PBF-LB process was large enough to require modification of the molding conditions.

Free Research Field

接合工学

Academic Significance and Societal Importance of the Research Achievements

C/C複合材やセラミクスなどの高温部材に従来接合困難とされてきた耐熱超合金を接合する新しい方法を開発した。レーザ式粉体溶融法（PBF-LB）といった三次元付加製造を生産工学における新しい可能性を示すことができた。また，PBF-LBを模擬する溶融凝固現象を考慮した数値計算方法の開発やNi基合材のCTE値測定などの成果が副次的に得られた。