Investigation of Adhesion and Fracture Toughness of Thermally Grown Oxide Scales by Interface Indentation Test
来源期刊:材料热处理学报2004年第5期
论文作者:ZHANG Zhan-ping
关键词:Interface indentation test; oxide adhesion; Fracture toughness; Nickel oxide;
摘 要:The adhesion and the fracture toughness of thermally grown oxide scales for pure nickel were investigated using Vickers indentation technique. The nickel samples were oxidised at 1200℃ for 100h-600h. The crack length induced by Vickers indentation test at NiO/Ni interface increases linearly with the incresing of the applied load in a logarithmic scale for each oxide thickness. There is a critical load Pc, when the applied load P>Pc, the crack is produced at the oxide/metal interface. The critical load Pc decreases with the increasing of the oxide thickness. Therefore, the relation between the critical load Pc and the oxide thickness ho may be used as describing the adhesion of of thermally grown oxide scales. For pure nickel, the Pc-ho relation can be represented by the equation Pc = 761439e-0.0695h. The fracture toughness in oxide and at the interface decrease with the increasing of the oxide thickness in equation Ko = -1.0214Ln(ho) + 7.3382 (in oxide) and Ki = 529.71ho-0.9424 (at the interface). And there is a higher fracture toughness at the NiO/Ni interface. Therefore,for pure nickel, the oxide/metal interface is stronger than the oxide.
P. Lours1,QI Yu-hong2,p. Bruckel1,ZHANG Zhan-ping2
(1.Research Centre on Tools, Materials and Processes, Ecole des Mines d'Albi-Carmaux, France;
2.Institute of Materials and Technology, Dalian Maritime University, Dalian, China)
摘要:The adhesion and the fracture toughness of thermally grown oxide scales for pure nickel were investigated using Vickers indentation technique. The nickel samples were oxidised at 1200℃ for 100h-600h. The crack length induced by Vickers indentation test at NiO/Ni interface increases linearly with the incresing of the applied load in a logarithmic scale for each oxide thickness. There is a critical load Pc, when the applied load P>Pc, the crack is produced at the oxide/metal interface. The critical load Pc decreases with the increasing of the oxide thickness. Therefore, the relation between the critical load Pc and the oxide thickness ho may be used as describing the adhesion of of thermally grown oxide scales. For pure nickel, the Pc-ho relation can be represented by the equation Pc = 761439e-0.0695h. The fracture toughness in oxide and at the interface decrease with the increasing of the oxide thickness in equation Ko = -1.0214Ln(ho) + 7.3382 (in oxide) and Ki = 529.71ho-0.9424 (at the interface). And there is a higher fracture toughness at the NiO/Ni interface. Therefore,for pure nickel, the oxide/metal interface is stronger than the oxide.
关键词:Interface indentation test; oxide adhesion; Fracture toughness; Nickel oxide;
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