1992 Fiscal Year Final Research Report Summary
DEVELOPMENT OF FUNCTIONALLY GRADIENT COATINGS FOR WEAR-RESISTANCE BY LASER SPRAYING
| Project/Area Number |
03555033
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械要素
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| Research Institution | KYUSHU INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
KANETA Motohiro KYUSHU INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING, PROFESSOR, 工学部, 教授 (90039123)
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| Co-Investigator(Kenkyū-buntansha) |
YONEDA Masafumi GOVERNMENT INDUSTRIAL RESEARCH INSTITUTE, SHIKOKU, CHIEF INVESTIGATOR, 四国工業技術試験所, 室長
KATSUMURA Munehide GOVERNMENT INDUSTRIAL RESEARCH INSTITUTE, SHIKOKU, CHIEF SENIOR RESEARCHER, 四国工業技術試験所, 首席研究官
NISHIKAWA Hiroshi KYUSHU INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING, RESEARCH ASSOCIATE, 工学部, 助手 (40208161)
MATSUDA Kenji KYUSHU INSTITUTE OF TECHNOLOGY FACULTY OF ENGINEERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (40229480)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Tribology / Wear resistance / Thermal shock resistance / Surface modification / Functionally gradient coatings / Laser spraying / Titanium / Titanium nitride |
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| Research Abstract |
Functionally gradient coatings, which consists of titanium and titanium nitride, have been developed by a laser spraying method. The spray gun has a center outlet for a wire as a spraying material and two coaxial ring-nozzles for assist gas. A titanium wire was melted by a high-energy-density carbon dioxide laser beam. An argon stream produced a fine spray of melted titanium particles which coated an aluminum and a mild steel substrates. The subsequent layers having different ratio of titanium nitride content to titanium were formed by changing the argon-to-nitrogen ratio in the gas. The last layer was coated with titanium nitraide by using nitrogen only. The chemical components of each layer were graded through the coatings (about 1 mm thick); the hardness and the thermal expansion coefficient of each layer are graded through the coatings. The reversal gradient coatings were also produced by the reverse process. The functionally gradient coatings produced have the following characteristics: (1)Excellent resistance for repeated thermal shock. (2)The hard surface coatings provide a good wear resistance. (3)The wear resistance is not influenced by the order of coatings and the degree of graduation but depends on the hardness of the rubbing surface. The higher hardness of the surface, the higher wear resistance. (4)The adhesion strength between the coated film and the substrate material under rubbing conditions increases with increase in the coating thickness. The adhesion strength in case where the substrate is coated with titanium nitride is stronger than that in case where the substrate is coated with titanium.
That is, the developed compositionally gradient laser-sprayed coatings can provide a good wear resistance and thermal shock resistance surface if they have a relatively thick layer of titanium nitride at the surface and a low titanium nitride content film on the substrate.
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Research Products
(6 results)
