This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused laye...This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused layer. XRD and SEM energy spectrum prove that trace RE element actually penetrates into the surface layer of steels. The result shows that RE can reduce the gradient of change of hardness in diffused layer, improve the morphology and distribution of compounds , and reduce the degree of surface alligator crack for thermal fatigue. The behavior of thermal fatigue of hot-working die steels is raised by 70% or so after the application of RE. The effect of RE is analysed according to the theory.展开更多
Sodium beta alumina（Na-β-alumina） films were synthesized by heat treatment of NaAl6O（9.5）and γ-NaA1O2 films at temperatures of 1 373-1 573 K.Single-phase γ-NaA1O2 and NaAl6O（9.5） films were prepared by laser ...Sodium beta alumina（Na-β-alumina） films were synthesized by heat treatment of NaAl6O（9.5）and γ-NaA1O2 films at temperatures of 1 373-1 573 K.Single-phase γ-NaA1O2 and NaAl6O（9.5） films were prepared by laser chemical vapor deposition at the deposition temperatures of 976 and 1 100 K,respectively.Subsequent heat treatment of the films resulted in the formation of Na-β-alumina with α-Al2O3 at temperatures above 1 373 K for NaAl6O（9.5） and 1 473 K for γ-NaA1O2.On heat treatment at temperatures of 1 473-1 573 K,the faceted morphology with terraces of the as-deposited（110）-oriented γ-NaAlO2 films transformed to a porous morphology with platelet grains comprising Na-β-alumina and α-Al2O3.On heat treatment at temperatures of1 373-1 473 K,the pyramidal,faceted grains of as-deposited NaAl6O（9.5） films transformed to planer,shapeanisotropic morphology in the film of mixed Na-β-alumina and α-Al2O3.A dense morphology was observed in both the as-deposited and heat-treated NaAl6O（9.5） films.展开更多
TiO_2 films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO...TiO_2 films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO2 films were investigated through SEM, TEM, X-ray diffraction analysis, Raman spectroscopy, FTIR, and XPS. The results showed that when being heat-treated at 600 ℃, the amorphous TiO_2 film transfered to the anatase film which bonded well with diamond substrate. Meanwhile, the Ti-O-C bond formed between TiO2 film and diamond substrate. When being heat-treated at 800 ℃, TiO2 film was still anatase, and partial diamond began to graphitize. The graphitizated carbon could also form the Ti-O-C bond with TiO_2 film, although TiO_2 film would tend to crack in this case.展开更多
文摘This paper studies a compound treatment. i. e. liquid S , N,C co-diffusing with rare earth (RE) and then oxidization , for hot-working die steels , and the effect of RE on thermal fatigue behavior of the diffused layer. XRD and SEM energy spectrum prove that trace RE element actually penetrates into the surface layer of steels. The result shows that RE can reduce the gradient of change of hardness in diffused layer, improve the morphology and distribution of compounds , and reduce the degree of surface alligator crack for thermal fatigue. The behavior of thermal fatigue of hot-working die steels is raised by 70% or so after the application of RE. The effect of RE is analysed according to the theory.
基金Funded by the Ministry of Education,Culture,Sports,Science and Technology,a Grant-in-Aid for Challenging Exploratory Research(No.26560235)the ARCMG–IMR Cooperative Program(No.14G0402)of Tohoku Universitythe China Scholarship Council and the 111 Project(No.B13035)of China
文摘Sodium beta alumina（Na-β-alumina） films were synthesized by heat treatment of NaAl6O（9.5）and γ-NaA1O2 films at temperatures of 1 373-1 573 K.Single-phase γ-NaA1O2 and NaAl6O（9.5） films were prepared by laser chemical vapor deposition at the deposition temperatures of 976 and 1 100 K,respectively.Subsequent heat treatment of the films resulted in the formation of Na-β-alumina with α-Al2O3 at temperatures above 1 373 K for NaAl6O（9.5） and 1 473 K for γ-NaA1O2.On heat treatment at temperatures of 1 473-1 573 K,the faceted morphology with terraces of the as-deposited（110）-oriented γ-NaAlO2 films transformed to a porous morphology with platelet grains comprising Na-β-alumina and α-Al2O3.On heat treatment at temperatures of1 373-1 473 K,the pyramidal,faceted grains of as-deposited NaAl6O（9.5） films transformed to planer,shapeanisotropic morphology in the film of mixed Na-β-alumina and α-Al2O3.A dense morphology was observed in both the as-deposited and heat-treated NaAl6O（9.5） films.
基金Funded by National Natural Science Foundation of China(No.51375157)Shanghai Aerospace Eighth Research Institute SAST Foundation(No.2015044)+1 种基金the Central University Basic Scientific Research Business Expenses,State Key Laboratory of Silicate Materials for Architectures Program(No.SYSJJ2015-09)the Hunan Province Key Laboratory of Environmental Photocatalysis Application Technology Program(No.CCSU-KF-1504)
文摘TiO_2 films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO2 films were investigated through SEM, TEM, X-ray diffraction analysis, Raman spectroscopy, FTIR, and XPS. The results showed that when being heat-treated at 600 ℃, the amorphous TiO_2 film transfered to the anatase film which bonded well with diamond substrate. Meanwhile, the Ti-O-C bond formed between TiO2 film and diamond substrate. When being heat-treated at 800 ℃, TiO2 film was still anatase, and partial diamond began to graphitize. The graphitizated carbon could also form the Ti-O-C bond with TiO_2 film, although TiO_2 film would tend to crack in this case.
