Ni-20Cr powders mixed with tungsten,aluminum,titanium,and different contents of molybdenum disulfides were hot-pressed in graphite mould by powder metallurgy method. Their tribological properties from room temperature...Ni-20Cr powders mixed with tungsten,aluminum,titanium,and different contents of molybdenum disulfides were hot-pressed in graphite mould by powder metallurgy method. Their tribological properties from room temperature to 600 ℃ and mechanical properties at atmosphere were tested. The results show that the hardness and anti-bending strength of composites increase by more than 20% when containing 6%(mass fraction) MoS2. But when molybdenum disulfide content exceeds 6%,the hardness and anti-bending strength will decrease gradually. The addition of MoS2 is favored to the reduction of friction coefficient of composite. The friction coefficient of composite decreases with the increase of molybdenum disulfide until the percentage of lubricant reaches 12%. In excess of this value,the friction coefficient value starts to ascend. The wear rates of composite with molybdenum disulfide are one order of magnitude lower than the alloy without lubricant. When the addition amount of MoS2 is in the range of 6% and 12%,the wear rates keep at the resemble level.展开更多
Nickel-based graphite-containing composites were prepared by powder metallurgy method. The effect of graphite addition on mechanical properties of nickel-based alloy was investigated and the tribological properties fr...Nickel-based graphite-containing composites were prepared by powder metallurgy method. The effect of graphite addition on mechanical properties of nickel-based alloy was investigated and the tribological properties from room temperature to 600 ℃ were tested by a pin-on-disk tribometer with alumina,silicon nitride and nickel-based alloy as counterfaces. The microstructure was analyzed by X-ray diffraction(XRD) and scanning electron microscope(SEM) attached with energy dispersive spectroscopy(EDS). The worn surfaces at high temperature were observed by optical microscope and SEM. The results show that the tensile strength and hardness of composites decrease after adding graphite,while the friction and wear properties are all improved by adding 12%(mass fraction) graphite. Compared with the counterface of alumina and silicon nitride,the friction coefficients and wear rates are lower when the composite rubs against nickel-based alloy containing molybdenum disulfide.展开更多
研究了Ni Cr Mo S合金的自润滑机理。结果表明:合金的显微组织主要是由金属基体和硫化物相与Ni(Cr)合金形成的共晶体两部分构成。随着温度的升高,Ni Cr Mo S合金的摩擦因数逐渐降低;合金材料中生成的共晶体在摩擦面的温度作用下可以变...研究了Ni Cr Mo S合金的自润滑机理。结果表明:合金的显微组织主要是由金属基体和硫化物相与Ni(Cr)合金形成的共晶体两部分构成。随着温度的升高,Ni Cr Mo S合金的摩擦因数逐渐降低;合金材料中生成的共晶体在摩擦面的温度作用下可以变软或熔化形成具有转移性的自润滑膜。在实验的高温下,MoO3和NiO也参与了润滑作用:随着温度的上升,MoO3所起的固体润滑作用逐渐减小,NiO所起的固体润滑作用逐渐增大。在室温摩擦时,轻微粘着磨损为主要磨损形式;在高温摩擦时,磨粒磨损为主要磨损形式,同时也会出现氧化磨损。展开更多
基金Project(BG2007046) supported by the High Technology Research of Jiangsu ProvinceProject(06-A-044) supported by the "Six Kinds of Excellent Peak" of Personnel Office of Jiangsu ProvinceProject(JHB06-04) supported by the College Scientific Research Production Translation of Jiangsu Educational Office
文摘Ni-20Cr powders mixed with tungsten,aluminum,titanium,and different contents of molybdenum disulfides were hot-pressed in graphite mould by powder metallurgy method. Their tribological properties from room temperature to 600 ℃ and mechanical properties at atmosphere were tested. The results show that the hardness and anti-bending strength of composites increase by more than 20% when containing 6%(mass fraction) MoS2. But when molybdenum disulfide content exceeds 6%,the hardness and anti-bending strength will decrease gradually. The addition of MoS2 is favored to the reduction of friction coefficient of composite. The friction coefficient of composite decreases with the increase of molybdenum disulfide until the percentage of lubricant reaches 12%. In excess of this value,the friction coefficient value starts to ascend. The wear rates of composite with molybdenum disulfide are one order of magnitude lower than the alloy without lubricant. When the addition amount of MoS2 is in the range of 6% and 12%,the wear rates keep at the resemble level.
基金Project(BG2007046) supported by the High Technology Research of Jiangsu ProvinceProject(06-A-044) supported by the "Six Kinds of Excellent Peak" of Personnel Office of Jiansu ProvinceProject(JHB0604) supported by the College Scientific Research Production Translation Jiangsu Educational Office
文摘Nickel-based graphite-containing composites were prepared by powder metallurgy method. The effect of graphite addition on mechanical properties of nickel-based alloy was investigated and the tribological properties from room temperature to 600 ℃ were tested by a pin-on-disk tribometer with alumina,silicon nitride and nickel-based alloy as counterfaces. The microstructure was analyzed by X-ray diffraction(XRD) and scanning electron microscope(SEM) attached with energy dispersive spectroscopy(EDS). The worn surfaces at high temperature were observed by optical microscope and SEM. The results show that the tensile strength and hardness of composites decrease after adding graphite,while the friction and wear properties are all improved by adding 12%(mass fraction) graphite. Compared with the counterface of alumina and silicon nitride,the friction coefficients and wear rates are lower when the composite rubs against nickel-based alloy containing molybdenum disulfide.
文摘研究了Ni Cr Mo S合金的自润滑机理。结果表明:合金的显微组织主要是由金属基体和硫化物相与Ni(Cr)合金形成的共晶体两部分构成。随着温度的升高,Ni Cr Mo S合金的摩擦因数逐渐降低;合金材料中生成的共晶体在摩擦面的温度作用下可以变软或熔化形成具有转移性的自润滑膜。在实验的高温下,MoO3和NiO也参与了润滑作用:随着温度的上升,MoO3所起的固体润滑作用逐渐减小,NiO所起的固体润滑作用逐渐增大。在室温摩擦时,轻微粘着磨损为主要磨损形式;在高温摩擦时,磨粒磨损为主要磨损形式,同时也会出现氧化磨损。
