The microstructures and mechanics properties of TiC-based cermets composed of TiC, WC, Ni, Co, Mo, and Cr3C2 were investigated. The results show that Mo has a great effect on the sintering densification, microstructur...The microstructures and mechanics properties of TiC-based cermets composed of TiC, WC, Ni, Co, Mo, and Cr3C2 were investigated. The results show that Mo has a great effect on the sintering densification, microstructures, and mechanical properties. The microstructures and distribution of Mo and Ti in the TiC-based cermets were analyzed. It was indicated that a new phase with Ti, Mo, W, and C was formed on the rim of （Ti,W）C grains by means of an addition of Mo into the TiC-based cermets. The new phase with a surrounding structure was of great aid to improve the wettability of the liquid phase on the solid phase surface of TiC, decrease the porosity and refine the grains of the hard phase, which gave rise to the increase in strength and hardness. The properties of the TiC-based cermets could be further improved to some extent by adding WC, Cr2C3, and Co.展开更多
AlCrN coating was prepared on the surface of TiC-based cermet cutting tool with cathodic arc ion plating,and the surface-interface morphologies,compositions of chemical elements,and phases were analyzed by scanning el...AlCrN coating was prepared on the surface of TiC-based cermet cutting tool with cathodic arc ion plating,and the surface-interface morphologies,compositions of chemical elements,and phases were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD),respectively.Bonding strength of the coating-substrate interface was measured with scratching test,and the wear mechanism and friction coefficient of TiC-based cermet cutting tool and AlCrN coating were investigated with friction and wear testing machine.The results show that the interface binding of AlCrN coating is metallurgical mode,and its binding strength is 83 N.The average friction coefficient of TiC-based cermet cutting tool under the load of 6 N is 0.8409,while that under the load of 8 N decreases by about 11%,and the wear mechanism of TiC cermet cutting tool is fatigue wear,abrasive wear,and oxidation wear.The average friction coefficient of AlCrN coating is 0.6363 under the load of 6 N,and the change is relatively stable,decreasing by about 25%than that of TiC-based cermet cutting tool;when the load increases to 8 N,the average friction coefficient of AlCrN coating decreases by 9%.The wear mechanism of AlCrN coating is abrasive wear and oxidation wear,showing lower friction coefficient and good wear resistance.展开更多
Steel reinforced TiC composites are an attractive choice for wear resistance and corrosion resistance applications. TiC- reinforced 17-4PH maraging stainless matrix composites were processed by conventional powder met...Steel reinforced TiC composites are an attractive choice for wear resistance and corrosion resistance applications. TiC- reinforced 17-4PH maraging stainless matrix composites were processed by conventional powder metallurgy （P/M）. TiC-reinforced maraging stainless steel composites with 〉97% of theoretical density were fabricated. The microstructure, mechanical and wear properties of the composites were evaluated. The microstructure of these composites consisted of spherical and semi-spherical TiC particles. A few microcracks appeared in the composites, showing the presence of tensile stress in the composites produced during sintering. Typical properties, namely, hardness and bend strength were reported for the sintered composites. After heat treatment and aging, the increase of hardness was observed. The increase of hardness was attributed to the aging reaction in the 17-4PH stainless steel. The precipitates appeared in the microstructure and were responsible for the increase in hardness. The specific wear behavior of the composites was strongly dependent on the content of TiC particles, the interparticle spacing, and the presence of hard precipitates in the binder phase.展开更多
文摘The microstructures and mechanics properties of TiC-based cermets composed of TiC, WC, Ni, Co, Mo, and Cr3C2 were investigated. The results show that Mo has a great effect on the sintering densification, microstructures, and mechanical properties. The microstructures and distribution of Mo and Ti in the TiC-based cermets were analyzed. It was indicated that a new phase with Ti, Mo, W, and C was formed on the rim of （Ti,W）C grains by means of an addition of Mo into the TiC-based cermets. The new phase with a surrounding structure was of great aid to improve the wettability of the liquid phase on the solid phase surface of TiC, decrease the porosity and refine the grains of the hard phase, which gave rise to the increase in strength and hardness. The properties of the TiC-based cermets could be further improved to some extent by adding WC, Cr2C3, and Co.
基金financially supported by the Jiangsu Province Science and Technology Support Program(Industry)(No.BE2014818)。
文摘AlCrN coating was prepared on the surface of TiC-based cermet cutting tool with cathodic arc ion plating,and the surface-interface morphologies,compositions of chemical elements,and phases were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD),respectively.Bonding strength of the coating-substrate interface was measured with scratching test,and the wear mechanism and friction coefficient of TiC-based cermet cutting tool and AlCrN coating were investigated with friction and wear testing machine.The results show that the interface binding of AlCrN coating is metallurgical mode,and its binding strength is 83 N.The average friction coefficient of TiC-based cermet cutting tool under the load of 6 N is 0.8409,while that under the load of 8 N decreases by about 11%,and the wear mechanism of TiC cermet cutting tool is fatigue wear,abrasive wear,and oxidation wear.The average friction coefficient of AlCrN coating is 0.6363 under the load of 6 N,and the change is relatively stable,decreasing by about 25%than that of TiC-based cermet cutting tool;when the load increases to 8 N,the average friction coefficient of AlCrN coating decreases by 9%.The wear mechanism of AlCrN coating is abrasive wear and oxidation wear,showing lower friction coefficient and good wear resistance.
文摘Steel reinforced TiC composites are an attractive choice for wear resistance and corrosion resistance applications. TiC- reinforced 17-4PH maraging stainless matrix composites were processed by conventional powder metallurgy （P/M）. TiC-reinforced maraging stainless steel composites with 〉97% of theoretical density were fabricated. The microstructure, mechanical and wear properties of the composites were evaluated. The microstructure of these composites consisted of spherical and semi-spherical TiC particles. A few microcracks appeared in the composites, showing the presence of tensile stress in the composites produced during sintering. Typical properties, namely, hardness and bend strength were reported for the sintered composites. After heat treatment and aging, the increase of hardness was observed. The increase of hardness was attributed to the aging reaction in the 17-4PH stainless steel. The precipitates appeared in the microstructure and were responsible for the increase in hardness. The specific wear behavior of the composites was strongly dependent on the content of TiC particles, the interparticle spacing, and the presence of hard precipitates in the binder phase.
