Tailoring of Oxidation-Resistant Nb-base Alloys at Ultra-High Temperatures and Understanding of their Oxidation Mechanism

超高温抗氧化铌基合金的定制及其氧化机制的理解

• 批准号: 13650770
• 负责人: HABAZAKI Hiroki
• 金额: $ 0.45万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650770/
• 关键词: High temperature oxidation; Nb-Al-Cr alloys; Sputter deposition; Oxidation-resistant coating; Alumina scale; High temperature materials; SO_2; Sulfidation; スパッタ蒸着; 耐酸化性コーティング; アルミナスケール; SO_2; 硫化

Sputter-deposited Nb alloys containing both aluminum and chromium reveal high oxidation resistance above 1073 K, in contrast to less oxidation-resistant Nb-Al and Nb-Cr binary alloys. The oxidation of the ternary alloys generally follows the parabolic rate law, indicating that diffusional transport of matter is the rate-determining step. However, the high oxidation resistance of the ternary alloys containing about 40 at% niobium is not due to the formation of an alumina scale, but due to an outer chromia layer with the inner layer consisting of a mixture of alumina, chromium-niobium and/or aluminum-niobium double oxides. When the ternary alloys containing about 40 at% niobium were oxidized in O_2-SO_2 atmospheres, preferential oxidation of aluminum occurs as a consequence of a transient sulfidation of aluminum at the alloy/scale interface. However, the preferential oxidation results in internal oxidation of the alloys, not in the formation of continuous external alumina scale. Further increase in aluminum content by reducing niobium content, finally results in the formation of highly protective α-alumina scales above 1073 K. Coating of this aluminum-rich niobium alloy to niobium-base alloys with high mechanical properties at high temperatures may induce interdiffusion between the coating and substrate, leading to degradation of the oxidation resistance. The authors have successfully demonstrated that introduction of an anodic alumina layer between the coating and substrate as a diffusion barrier layer suppresses effectively the interdiffusion, thus high oxidation resistance of the coating is sustained at high temperatures.

溅射沉积的NB合金含有高于1073 K B-AL和NB-CR二进制二进制二元合金的高氧化耐药性。 。由于形成氧化铝尺度，因此三分之一的三元式氧化量为t是t，但是由于外部铬铁层的内在层，由铝，niobium和或铝niobium double氧化物组成。在O_2-SO_2大气中，由于合金/比例尺界面的铝制氧化而导致铝的优先氧化。高于1073 K的高度保护性α-氧化铝尺度。尼伯碱合金的涂层与ynduce interdiffueen。涂层在高温下持续。

项目成果

H.Habazaki: "Sulfidation-and oxidation-resistant Nb-Al-Si alloy coatings prepared by sputter deposition"Materials at High Temperatures. 18. 95-100 (2001)

H.Habazaki：“通过溅射沉积制备的抗硫化和抗氧化的Nb-Al-Si合金涂层”高温材料。

K.Yoshimi: "Oxidation behavior of Mo_5SiB_2-based alloy at elevated temperatures"Intermetallics. 10. 407-414 (2002)

K.Yoshimi：“Mo_5SiB_2基合金在高温下的氧化行为”金属间化合物。

K. Hashimoto, H. Habazaki, M. Yamazaki, A. Kawashima, K. Izumiya, H. Ukai, K. Asami, S. Meguro: "Extremely corrosion-resistant bulk amorphous alloys"Mater. Sci. Forum. 377. 1-8 (2001)

K. Hashimoto、H. Habazaki、M. Yamazaki、A. Kawashima、K. Izumiya、H. Ukai、K. Asami、S. Meguro：“极耐腐蚀大块非晶合金”。

K.Hashimoto: "Extremely corrosion-resistant bulk amorphous alloys"Materials Science Forum. 377. 1-8 (2001)

K.Hashimoto：“极耐腐蚀大块非晶合金”材料科学论坛。

H. Habazaki, H. Mitsui, K. Asami, K. Hashimoto, S. Mrowec: "Roles of aluminium and chromium in sulfidation and oxidation of sputter-deposited Al-and Cr-refractory metal alloys"Corros. Sci.. 44. 285-302 (2002)

H. Habazaki、H. Mitsui、K. Asami、K. Hashimoto、S. Mrowec：“铝和铬在溅射沉积铝和铬难熔金属合金的硫化和氧化中的作用”Corros。