This paper deals with the fabrication of titanium carbide using fine titanium hydride. The ratio of and C (Activated carbon) was 1:1 (mol) and milled in a planetary ball mill at a ball-to-powder weight ratio of 20:1. Thereafter, TGA was performed at to observe change of weight with milling time. Titanium carbide was obtained by using tempering the milled powders at . The microstructures of titanium carbide as well as the change of the lattice parameters and particle size have been studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Ultrafine titanium carbide particles were synthesized by the reaction of liquid-magnesium and vaporized TiCl+CCl(x = 1 and 2) solution. Fine titanium carbide particles with about 50 nm were successfully produced by combining Ti and C atoms released by chloride reduction of magnesium, and vacuum was then used to remove the residual phases of MgCl and excess Mg. Small amounts of impurities such as O, Fe, Mg and Cl were detected in the product, but such problem can be solved by more precise process control. The lattice parameter of the product was 0.43267 nm, near the standard value. With respect to the reaction kinetics, the activation energy for the reactions of TiCl+CCland Mg was found to 69 kJ/mole, which was about half value against the use of TiCl+CCl, and such higher reactivity of the former contributed to increase the stoichiometry until the level of TiC and decrease the free carbon content below 0.3 wt.%.

티타늄 및 티타늄합금은 강도/밀도 비가 높고, 내열성, 내부식성, 피로강도가 높기 때문에 지금까지 항공, 우주, 해양 및 화학 장치용 소재로서 많이 사용되어 왔다. 최근, 자동차 산업과 레저용 제품 등의 성능과 효율향상을 위해 항공ㆍ우주 산업이나 특수화학장치 산업에 한정되어 사용되고 있던 티타늄소재를, 이들 산업으로 확대하여 응용하고 있다. (중략)

In the present study, the focus is on the analysis of carbothermal reduction of the titanium-cobalt-oxygen based oxide powder by solid carbon for the optimizing synthesis process of ultra fined TiC/Co composite powder. The titanium-cobalt-oxygen based oxide powder was prepared by the combination of the spray drying and desalting processes using the titanium dioxide powder and cobalt nitrate as the raw materials. The titanium-cobalt-oxygen based oxide powder was mixed with carbon black, and then this mixture was carbothermally reduced under a flowing argon atmosphere. The changes in the phase structure and thermal gravity of the mixture during carbothermal reduction were analysed using XRD and TGA. The synthesized titanium-cobalt-oxygen based oxide powder has a mixture of and . This oxide powder was transformed to a mixed state of titanium car-bide and cobalt by solid carbon through four steps of carbothermal reduction steps with increasing temperature; reduction of to and Co, reduction of , to the magneli phase(, n>3), reduction of the mag-neli phase(, n>3) to the (2n3) phases, and reduction and carburization of the (2n3) phases to titanium carbide.

Ultra fine titanium carbide particles were synthesized by novel metallic thermo-reduction process. The vaporized TiC1+ gases were reacted with liquid magnesium and the fine titanium carbide particles were then produced by combining the released titanium and carbon atoms. The vacuum treatment was followed to remove the residual phases of MgC1 and excess Mg. The stoichiometry, microstructure, fixed and carbon contents and lattice parameter were investigated in titanium carbide powders produced in various reaction parameters.

Cell adhesion is used as a parameter to evaluate the biocompatibility of dental implant and also affected by the surface form of dental implant. Most study have showed different cell reaction by the composition and the surface morphology of implant. Therefore it is thought that the osteoblastic activity would be affected by the surface roughness and composition of implants. This study was performed to evaluate the biological activity and morphological change of normal human osteoblastic cells(NHost) depending on the variations of implant surfaces. We used grade 2 titanium disks which were being air-blasted with TiO2 50 ㎛, 110 ㎛, 250 ㎛ powder by 3psi compressed air and non-blasted as control. We evaluated and compared morphologic change, adhesion assay, and Ca, P, ALP concentration of NHost in vitro. The obtained results were as follows. 1. In the growth curve, although the growth of experimental groups were lower than that of the group of NHost only, there was no significant difference between each groups. 2. Inverted microscopic findings showed NHosts in early stage of each group were adherant perpendicular to the titanium disk and the multilayered NHosts were attached with various directions after 4 weeks. 3. Scanning electron microscopic(SEM) features showed that NHosts in all groups seemed to be attached multilayered and connected with each process after 2 weeks. 4. NHosts' processes were found by the SEM after one day culture. The cell adhesion of experiment group was higher than that of control group. 110 ㎛(the 3rd group) showed prominant process of NHost on the titanium disk surface. 5. Although the concentrations of Ca, P and ALP were gradually reduced, ANOVA analysis of each groups were partially different, and ANOVA analysis of 4th group were significantly different with others. From the aboving results, NHosts cultured on the titanium disks showed similar morphological change and cell proliferation. There were partially differences in each group except the 4th group, and the 4th group were significantly different with other's in biological activity. We thought that biological activity and adhesion of NHost cell on titanium had been affected by the variation of the titanium surface roughness.