No abstract

Ti(C, N)-based cermet materials represent the best choice of materials for the manufacturing industry and military products. In this study, we use cubic β-cobalt(β-Co) as the binder phase to strengthen constructed cermets. At the same time, to optimize the microstructure, (Ti, W, Mo, Ta) (C, N) powders are added to form two kinds of core-rim morphologies. Here, β-cobalt powders with face-centered cubic structures are obtained by the solid-phase reaction of high-energy ball milling. A solid-phase chemical reaction and a carbothermic reduction-nitridation method are used to prepare the (Ti, W, Mo, Ta) (C, N) powders. In our process, first we mix the cobalt and (Ti, W, Mo, Ta) (C, N) powders; then we press the powder mixtures into rectangular samples and sinter them in a pressure sintering furnace to obtain Ti(C, N)-based cermets with two kinds of core-rim structure, that is, black core/ white rim and white core/gray rim. e results show that the new cermets demonstrate excellent toughness and performance.

Ni-Co binary coatings with different compositions were electrodeposited from sulphate and chloride baths at room temperature without stirring, respectively. The different codeposition behaviors of the coatings deposited from sulphate and chloride with the same mole ratio of Ni2+/Co2+were studied and anomalous codeposition was investigated in both the sulphate and chloride baths. The Co atom content in the coatings deposited from chloride bath and sulphate bath increases with the mole ratio of Co2+/Ni2+in the baths increasing. The degree of anomalous codeposition in the sulphate bath is higher than that in chloride bath and the possible explanation was discussed. The difference of magnetic properties was also investigated.

Carbon-doped Ti-O films were deposited on steel and silicon wafer by DC reaction magnetron sputtering (R-MS) using CO2 as carbon and oxygen source. A series of films were prepared by means of changing the flow of CO2 or O2. The effects of annealing temperature ranging from 300 to 650°C on the properties of Ti-O films under vacuum were studied. X-ray diffraction (XRD) and field emission scanning electronic microscope (FESEM) were employed to analyze and observe structure and morphology of pre-or after-annealed Ti-O films. nanoindentation was used to measure nanohardness and modulus, and recovery was also calculated by the curves of load-displacement. Roughness and thickness were estimated by surface profiler. The XRD studies revealed that the doping of carbon was beneficial to the crystallization of the films. The results showed that the particle size of Ti-O films increased with the increase of annealing temperature, as-annealed carbon-doped Ti-O films have fair mechanical performance.