TiH2 nanopowder was made by high energy ball milling. The milled TiH2 and CNT powders were then simultaneously synthesized and consolidated using pulsed current activated sintering (PCAS) within one minute under an applied pressure of 80 MPa. The milling did not induce any reaction between the constituent powders. Meanwhile, PCAS of the TiH2-CNT mixture produced a Ti-TiC composite according to the reaction (0.92TiH2 + 0.08CNT→0.84Ti + 0.08TiC + 0.92H2, 0.84TiH2 + 0.16CNT→0.68Ti + 0.16TiC + 0.84H2). Highly dense nanocrystalline Ti-TiC composites with a relative density of up to 99.7% were obtained. The hardness and fracture toughness of the dense Ti-8 mole% TiC and Ti-16 mole% TiC produced by PCAS were also investigated. The hardness of the Ti-8 mole% TiC and Ti-16 mole% TiC composites was higher than that of Ti. The hardness value of the Ti-16 mole% TiC composite was higher than that of the Ti-8 mole% TiC composite without a decrease in fracture toughness.

In order to clarify the effect of C/Ti atom ratios(χ) on the deformation behavior of TiCχ at high temperature, singlecrystals having a wide range of χ, from 0.56 to 0.96, were deformed by compression test in a temperature range of 1183~2273Kand in a strain rate range of 1.9×10−4~5.9×10−3s−1. Before testing, TiCχ single crystals were grown by the FZ method ina He atmosphere of 0.3MPa. The concentrations of combined carbon were determined by chemical analysis and the latticeparameters by the X-ray powder diffraction technique. It was found that the high temperature deformation behavior observedis the χ-less dependent type, including the work softening phenomenon, the critical resolved shear stress, the transitiontemperature where the deformation mechanism changes, the stress exponent of strain rate and activation energy for deformation.The shape of stress-strain curves of TiC0.96, TiC0.85 and TiC0.56 is seen to be less dependent on χ, the work hardening rate afterthe softening is slightly higher in TiC0.96 than in TiC0.85 and TiC0.56. As χ decreases the work softening becomes less evidentand the transition temperature where the work softening disappears, shifts to a lower temperature. The τc decreasesmonotonously with decreasing χ in a range of χ from 0.86 to 0.96. The transition temperature where the deformationmechanism changes shifts to a lower temperature as χ decreases. The activation energy for deformation in the low temperatureregion also decreased monotonously as χ decreased. The deformation in this temperature region is thought to be governed bythe Peierls mechanism.

Ti(C,N) solid solutions in hot-pressed Ti() (x=0.0, 0.3, 0.5, 0.7, 1.0) and 40TiC-40TiN-20Ni (in wt.%) cermet were characterized in this study. For hot-pressed Ti(C,N)s, the lattice parameters and hardness values of Ti(C,N) were determined by using XRD (X-Ray Diffraction) and nanoindentation. The properties of hot-pressed Ti(C,N) samples changed linearly with their carbon or nitrogen contents. For the TiC-TiN-Ni cermet, the hardness of the hard phase and binder phase were determined by nanoindentation in conjunction with microstructural observation. The measured hardness values were GPa for the binder phase and GPa for the hard phase, which was close to the hardness of hot-pressed Ti().

Ti 안경 태 의 nm 부분과 temple 부분을 분리 한 후， temple 부분을 시 료로 사용하 였다. 실험에 사용한 장비는 아크 이온플레이팅 장비이며， 이 장비를 이용하여 TiN과 TiC 이온도금을 하였다. Ti temple의 성분과 TiN, TiN 도금층과 TiC 도금층의 과 밀착성 시험을 행하였다. 그 결과， TiN temple은 Al을 첨가한 알파형 티탄테 temple이었으며， TiN 이온도금 층은 XPS data로부터 TiN으로， Ti와 결합을 잘하는 Oxygen이나 Carbon과의 결합 이 없다는 것을 알 수 있었다. 염수분무시험에서는 10 일이 경과 후에도 “이상없음”으 로 결과가 나왔으며， 이온도금층의 두께는 약 l.9 ]lm 이었다. 밀착성 시험에서 180。굽 혔을 때 도금층의 박리가 육안으로도 없었으며， 색상은 골드색에 가까운 색상이었다. TiC 이온도금층은 주로 TiC로 이루어져 있으며 N과 0가 약간 섞어있는 형태이었 다. 이온도금층의 두께는 약 l.6 jlm로 TíN 도금층보다 약간 작게 나왔으며， 염수분무 시험과 밀착성시험에서도 TiN 도금층과 같이 “이상없음”으로 결과가 나왔으며， 밀착 성 시험에서 도금층의 박리가 육안으로도 없었으며， 색상은 흑색이었다.

We have studied the effect of C/Ti atomic ratio of TiCx (x=0.5, 0.75 and 1.0) raw powder on the properties of the Ti-Mo-WTiC sintered hard alloy. The decrease of C/Ti atomic ratio accelerated the densification in the sintering process. The hardness was remarkably improved up to 1350HV with decreasing the C/Ti atomic ratio because of increase of TiCx phase volume content and its fine dispersion. From the results of electro-chemical tests in acid and 3% NaCl solutions, it was obvious that every alloy had excellent corrosion resistance, which meant about 200 times better than that of WC-Co cemented carbide.

본 연구는 티타늄과 활성탄소 원료분말을 반응밀링법에 의해 합성시, 밀링시간에 따른 Ti-TiC 복합재료의 미세조직과 기계적 성질에 미치는 TiC vol.% 및 열간압축성형온도의 영향에 관해 조사하였다. 티타늄과 활성 탄소 원료분말을 300시간 밀링 후 5μm이하의 미세한 구형의 Ti-TiC복합분말을 생성시킬 수 있었다. 반응밀링된 분말을 1000˚C이상에서 1시간동안 진공열간압축성형한 경우 이론밀도의 98%에 가까운 우수한 성형체를 얻었으며, TiC입자가 티타늄 기지 전반에 걸쳐 고르게 분산되어 Ti-TiC 복합재료의 기계적 특성을 향상시켰다. Ti-TiC복합재료의 고온안정성을 고찰하기 위해 600˚C등온열처리한 결과 80시간까지는 경도의 큰 변화없이 열적으로 안정하였다. Ti-20vol%TiC 복합재료를 700˚C에서 고온압축시험을 한 경우 330MPa의 높은 항복강도값을 나타내었다.