Development of the high performance metal surfaces due to femtosecond-laser-induced nanostructure formed on surface modification layer

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360312
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Fukui National College of Technology
• Principal Investigator: YASUMARU Naoki 福井工業高等専門学校, その他部局等, 教授 (90158006)
• Co-Investigator(Renkei-kenkyūsha): MIYAZAKI Kenzo 京都大学, エネルギー理工学研究所, 教授 (50293957) ; KATO Hirotaka 福井工業高等専門学校, 機械工学科, 教授 (30311020) ; EISUKE Sentoku 福井工業高等専門学校, 機械工学科, 講師 (10436834)
• Research Collaborator: KIUCHI Junsuke
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: フェムト秒レーザー / アブレーション / 合金鋼 / 表面硬化層 / 窒化 / ナノ構造 / DLC / トライボロジー

Outline of Final Research Achievements

This paper reports the experimental results on fs-laser-induced nanostructuring of nitrided die steel (1.5C-12Cr), nitrided stainless steel (18Cr-8Ni) and the low carbon steel (0.1C). The minimum value of the mean spacing D for the nanostructures formed on the alloy steels was λ/3. In contrast, D for the low-carbon steel was larger. These results suggest that chromium nitrides generated on the specimen surfaces induce a reduction in D. The ablation rates of unnitrided steels increased linearly against fluence F of a logarithmic scale, however, it should be noted that the rates of nitirided die or stainless steels exhibited higher values at a large value of F and increased in the second order curve with an increase in F. Furthermore, DLC film coated on the nanostructured nitrided die steel surface was found to be effective for the purpose of decreasing the friction coefficient also to the hardened steel ball.

Free Research Field

材料工学