クマゼミの胚および1齢幼虫の生理生態学的研究 : 気候変化に注目して

博士(理学)大阪市立大

TiN-TiAl複合体の機械的特性

applicationTiN-TiAl ceramics/intermetallic composites containing no additives were hot-pressed from a mixture of TiN, Ti and Al powders containing 5 up to 100massl%TiAl (5, 20, 40, 60, 80, 100mass%TiAl), which were formed from a reaction between Ti and Al. Hot-pressing was conducted at 1000℃ for 7.2 ks under a pressure of 13.9 MPa in an Ar gas atmosphere. The mechanical and electrical properties were examined as a function of compositional change from 5 to 100mass%TiAl. TiN-TiAl composites containing 60～100mass%TiAl had a relative density of 67.3～71.1%, bulk density of 2380～2830kg m^, Vickers hardness of 506～2771MPa, flexural strength of 50～123MPa, Young's modulus of 45.9～82.4GPa, and electrical conductivity of 606～778k S・m^. The sufficient densification was not necessarily performed because the reaction from Ti and Al to TiAl phase was not completed by the use of coase Ti and Al powders.departmental bulletin pape

CVD法を用いた絶縁性セラミックス膜の合成と特性評価

Alumina film was deposited on several metallic and ceramic substrates by thermal decomposition of metal-organic compound (aluminum-isopropoxide) using thermal CVD to get a insulated ceramic film. The film was characterized by a electric conductivity, morphology observation using scanning electron microscope (SEM), diffraction pattern of X-ray and film thickness.departmental bulletin pape

ホットプレス法によるTiB_2-ZrB_2系セラミックス焼結体の作製とその機械的特性

applicationThe TiB_2-ZrB_2 ceramic system, which have high hardnesses and electrical conductivities, were sintered by the hot-pressing method from the mixed powders of TiB_2 and ZrB_2. The mixed powders with the compositions from TiB_2 to ZrB_2 (0.2mol step) were calcined at 1450℃ and then hotpressed at 2000℃ for 3.6ks under a pressing pressure of 32MPa in ambient Ar gas of normal pressure. As a result, the system had the solid solutions between TiB_2 and ZrB_2 crystal structures. The (TiB_2)_0.6(ZrB_2)_0.4 ceramics, for example, had the relative density of 96.5%, hardness of 33GPa, flexural strength of 354MPa, fracture toughness (K) of 3.87 MPa m and Young's modulus of 449GPa. The ceramics is expected to use as ceramic mold materials that can form with electrical discharge machine, corrosion-resistant electrode materials, and electro-conductive hightemperature structural materials.departmental bulletin pape

常圧焼結TiNセラミックスの機械的及び電気的特性に及ぼすCIP成形圧の影響

applicationThe pure TiN ceramic compacts were manufactured by the pressure-less sintering method from pure TiN powders with no additives. The ball-milled TiN powders were pre-formed at a uni-axial pressure of 100MPa, and then CIPed (Cold iso-static pressured) at 0, 50, 100, 200, 300 and 350MPa, respectively. The green compacts were sintered at 2100℃ for 2h in ambient pure Ar gas. The sintered compacts had a relative density of 87.6～89.6%, linear contraction coefficient of 12.2～13.6%, hardness of 12.3～20.0GPa, tensile stress of 79.3～146.3MPa, tensile strain of 124～230με, Young's modulus of 313～366GPa, Rigidity of 131～150GPa, Poisson's ratio of 0.19～0.24 and electrical conductivity of 1.83～2.12MS m^". The ceramics is expected to be used as a ceramic mold material that can be machined by electrical discharge and as electro-conductive high-temperature structural materials.departmental bulletin pape

フェライト磁石の作製とその評価 : 学生実験

applicationThe experiment of making ferrite magnet has been introduced to the school experiment for fifth-grade students in the department of electronics and control engineering of Nagano National College of Technology since 1998. The intentions of designing this experiment are as follows. ① The students entertain friendly sentiments toward a functional material such as a magnet, ② they improve their knowledge of chemistry as they make the magnet using chemical reaction, ③ they can be interested in a hand-make magnet that is near by in the daily life. The largest feature of the experiment is that manufacturing process is highly pure chemical. The start materials are not regular raw powders sold on the market but chemical reagents such as FeCl_2 and BaCl_2. They react with NaOH and Na_2CO_3 in the liquid phase and precipitate the solid phase of both iron hydroxide and barium carbonate. The sediments are calcined at 950℃, formed under a pressure of 98MPa, sintered at 1100℃ for 7.2ks, and then magnetized in a strong magnetic field using solenoid coils. The students have to calculate the required moles of reagents based on the chemical reaction, and they can compare the experimental results with theoretical ones. They seem to be interested in the hand-made magnet and understand a chemical reaction.departmental bulletin pape

Electrochemical Nitrite-ion Sensor Based on Perovskite-type Oxide

九州工業大学博士学位論文 学位記番号：工博甲第492号 学位授与年月日：令和2年3月25日第1章 序論|第2章 ペロブスカイト型酸化物ナノ粉末の合成|第3章 種々のペロブスカイト型酸化物担持電極亜硝酸イオン応答特性|第4章 触媒担持電極材料の検討|第5章 塩基性条件での亜硝酸イオン応答特性|第6章 結論九州工業大学令和元年