Papers by Author: Xin Wang

Abstract: Steel-bonded cemented carbide GT35 was fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effects of C content on the mechanical properties and microstructures of GT35 composites were investigated. As an excellent reducer, carbon provides an impetus for a series of reductive process. C content determines the melting point of the steel matrix, and directly affects the mechanism of dissolving and segregating of TiC particles, forming a netlike microstructure. Besides, the liquid steel whose viscosplasticity is determined by C content was coated on the surface of the composite and refrained the release of CO. The results showed that the good mechanical properties of steel-bonded cemented carbide GT35 composite were obtained with 0.9wt.% C at the same sintering conditions and the density reached 6.12g/cm3, the average bending strength was over 1229MPa after heat treatment, the mean hardness HRC was 69.4. It also showed that in-situ reduction of natural limonite was a feasible way to fabricate good performance GT35 composite with a relatively low cost.

Abstract: In the present study, steel-bonded cemented carbide GT35 has been fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effect of different carbon source on the mechanical properties and microstructure of GT35 composite was studied. The quality of the composite synthesized from natural graphite is higher than those from other carbon source. Some good results were obtained from experiments: the density is about 6.2g/cm3, and the bending strength is 1390MPa, which higher than that of other samples. The structures and ingredient of different carbon source were analyzed to elucidate their different performance in the reactions.

Abstract: Steel-bonded cemented carbide GT35 was fabricated from natural ilmenite by in-situ carbothermic reduction and vacuum pressureless sintering. The effects of Mo-doped on the mechanical properties and microstructures of GT35 composites were investigated. That the good mechanical properties of steel-bonded cemented carbide GT35 with 9wt% Mo were obtained at the same sintering condition that the density reached 6.223g/cm3 and the average bending strength reached about 1155.6MPa after heat treatment, but the hardness dropped the lowest value HRC 60.94 and the difference was not apparent with the change of Mo content. The additive of Mo is beneficial to be refinement of carbide particle size, sphericity of grains and formation of compact composite. In-situ reduction of natural ilmenite was a feasible way to fabricate good performance composite GT35 with a relative low cost.