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Amano H., Yamaguchi Y., Ishimoto T., et al. Reduction of spatter generation using atmospheric gas in laser powder bed fusion of Ti-6Al-4V. Materials Transactions 62, 1225 (2021); https://doi.org/10.2320/matertrans.MT-M2021059., Laser powder bed fusion (LPBF), a typical additive manufacturing (AM) process, is a promising approach that enables high-accuracy manufacturing of arbitrary structures; therefore, it has been utilized in the aerospace and medical fields. However, several unexplained phenomena significantly affect the quality of fabricated components. In particular, it has been reported that the generation of spatters adversely affects the stability of fabrication process and degrades the performance of the fabricated components. To realize high-quality components, it is essential to suppress the generation of spatters. Thus far, the suppression of spatter generation has been attempted based on the process parameters; however, this has not been adequately discussed in terms of the fabrication atmosphere. Therefore, in this study, we focused on the fabrication atmosphere and investigated spatter generation using gas with different physical properties rather than conventionally used argon. It was observed that the spatter generation during the fabrication of the Ti6Al4V alloy could be significantly suppressed by changing the atmospheric gas, even under constant LPBF process parameters. We proved that the fabrication atmosphere is an important factor to be considered, apart from the process parameters, in AM technology.

Additional file 1.

For the construction of next-generation optical products and systems, the evolution of polariser sheets is a necessary requirement. To this end, a low-reflective wire-grid polariser (WGP) sheet for the visible light region is demonstrated, the nanowires of which consist of a sintered body of silver nanoparticle ink. The nanowires are formed by a nanoprinting process using a thermal nanoimprint method and ink filling. This process makes it easier to achieve multiple wafer-scale productions without using sophisticated equipment compared to conventional WGP nanofabrication techniques, which typically employ lithography and elaborate etching processes. The optical characteristics are controlled by the shape of the printed nanowires. A WGP sheet with a luminous degree of polarisation of 99.0%, a total luminous transmittance of 13.6%, and a luminous reflectance of 3.6% is produced. Its low reflectance is achieved through the uneven surface derived from the sintered body of the nanoparticle ink, and the shape of the bottom of the nanowire is derived from the tip shape of the mould structure. Furthermore, the printed WGP sheet has the durability required for the manufacturing of curved products, including sunglasses. The optical structures made of nanoparticle ink using this nanoprinting process have the potential to significantly contribute to the development of fine-structured optical elements with unprecedented functionality.

平成30年度宇宙輸送シンポジウム（2019年1月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2018 (January 17-18, 2019. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000136025, レポート番号: STCP-2018-025

Electrocatalytic Diels–Alder reactions have been designed and demonstrated based on the aromatic “redox tag” concept., Electrocatalysis was employed to promote Diels–Alder reactions between electronically mismatched substrates. A catalytic amount of electricity was enough to complete the overall reactions and GC-MS monitoring and CV measurements clearly illustrated the electrocatalytic nature of the reactions, which involve an EC-backward-E mechanism. The electrocatalytic Diels–Alder reactions were rationally designed based on the concept of redox tags. The results were supported by DFT calculations.

第33回宇宙構造・材料シンポジウム（2017年12月8日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)), 相模原市, 神奈川県, 33rd Symposium on Aerospace Structure and Materials (December 8, 2017. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000116002, レポート番号: A03

Results of the simulation study. We provide the following details related to designs and results of the simulation study: (i) density functions of the random effects distribution, (ii) full tables of the results, (iii) summary statistics of estimates for the transformation and the shift parameter. (PDF 2467 kb)

R code. Our Bayesian analyses in the simulation study and the application were implemented by using the R software. We provide R functions nremeta and bcremeta for the Bayesian estimations of the normal random effects model and the proposed model respectively. (PDF 45 kb)

平成27年度宇宙輸送シンポジウム（2016年1月14日-15日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県, Space Transportation Symposium FY2015 (January 14-15, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan, 資料番号: SA6000050040, レポート番号: STCP-2015-041