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Subsequent Heat Treatment (subsequent + heat_treatment)
Selected AbstractsSemi-Solid Processing of Tailored Aluminium-Lithium Alloys for Automotive Applications,ADVANCED ENGINEERING MATERIALS, Issue 4 2007R. Sauermann Abstract This paper describes the development and evaluation of thixoformable Al-Li-Mg-based alloys performed at the collaborative research center SFB 289, RWTH Aachen. Scandium and zirconium were added to AlLi2.1Mg5.5 (A1420) with the aid of DoE (Design of Experiments), and precursor billets were manufactured by pressure induction melting (PIM). To evaluate the thixoformability of the synthesized alloys semi-solid processed connecting rods were manufactured by the rheo container process (RCP). Subsequent heat treatment raised the mechanical properties to maximum values of tensile strength, 430,MPa, yield strength of 250,MPa, and an elongation to fracture of 13,%. The RCP process was designed for the special requirements of highly reactive alloys. The paper presents the remarkable property and process benefits of the semi-solid processing of Al-Li alloys. [source] Hafnium Oxide Doped Mesostructured Silica FilmsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 18 2007Ralf Supplit Abstract Hafnium oxide doped silica films with ordered mesostructures were produced with hafnium:silicon ratios between 1:60 and 1:6. A surfactant,hafnium alkoxide complex was synthesized and used as a template in a sol,gel dip-coating process. Face-centred orthorhombic, 2D centred rectangular and lamellar films were formed by evaporation-induced self-assembly (EISA). The influence of subsequent heat treatment was studied by GISAXS and TEM. The surface and in-depth molecular composition of the films was studied by XPS.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Solution-Deposited Zinc Oxide and Zinc Oxide/Pentacene Bilayer Transistors: High Mobility n-Channel, Ambipolar, and Nonvolatile Devices,ADVANCED FUNCTIONAL MATERIALS, Issue 12 2008Bhola Nath Pal Abstract A solution processed n-channel zinc oxide (ZnO) field effect transistor (FET) was fabricated by simple dip coating and subsequent heat treatment of a zinc acetate film. The field effect mobility of electrons depends on ZnO grain size, controlled by changing the number of coatings and zinc acetate solution concentration. The highest electron mobility achieved by this method is 7.2,cm2 V,1 s,1 with On/Off ratio of 70. This electron mobility is higher than for the most recently reported solution processed ZnO transistor. We also fabricated bilayer transistors where the first layer is ZnO, and the second layer is pentacene, a p-channel organic which is deposited by thermal evaporation. By changing the ZnO grain size (or thickness) this type of bilayer transistor shows p-channel, ambipolar and n-channel behavior. For the ambipolar transistor, well balanced electron and hole mobilities are 7.6,×,10,3 and 6.3,×,10,3,cm2 V,1 s,1 respectively. When the ZnO layer is very thin, the transistor shows p-channel behavior with very high reversible hysteresis. The nonvolatile tuning function of this transistor was investigated. [source] Ordered Mesoporous Thin Films of Rutile TiO2 Nanocrystals Mixed with Amorphous Ta2O5CHEMPHYSCHEM, Issue 5 2008Jin-Ming Wu Dr. Abstract Ordered mesoporous thin films of composites of rutile TiO2 nanocrystals with amorphous Ta2O5 are fabricated by evaporation-induced self-assembly followed by subsequent heat treatment beyond 780,°C. Incorporation of selected amounts of Ta2O5 (20 mol,%) in the mesoporous TiO2 film, together with the unique mesoporous structure itself, increased the onset of crystallization temperature which is high enough to ensure the crystallization of amorphous titania to rutile. The ordered mesoporous structure benefits from a block-copolymer template, which stabilizes the mesostructure of the amorphous mixed oxides before crystallization. The surface and in-depth composition analysis by X-ray photoelectron spectroscopy suggests a homogeneous intermixing of the two oxides in the thin film. A detailed X-ray absorption fine structure measurement on the composite film containing 20 mol,% Ta2O5 and heated to 800,°C confirms the amorphous nature of the Ta2O5 phase. Photocatalytic activity evaluation suggests that the rutile nanocrystals in the synthesized ordered mesoporous thin film possess good ability to assist the photodegradation of rhodamine B in water under illumination by UV light. [source] | |||||||||||||