Study On Preparation And Tribological Properties Of NiAl Matrix Self-lubricating Composites

Currently，solid self-lubricating composites over a wide temperature range aresignificantly needed to be researched. Compared with the traditional lubricants，solidlubricants have obvious advantages in the field of high temperature friction. But mostcommon lubricants only perform within a special temperature range，such asgraphite，molybdenum disulfide. Thus，the combination of two or more than twolubricants is one of the effective methods to realize lubrication over a widetemperature range.The study designs solid self-lubrication composites utilized in a widetemperature range from the wettability between the lubricant and matrix，thecombination of a variety of lubricant and lubricant addition amount. The NiAl baseself-lubrication composites containing Ti3SiC2，MoS2and nickel coated MoS2wereprepared by spark plasma sintering. The physical properties，mechanical propertiesand tribological properties from room temperature to600℃of NiAl baseself-lubrication composites were measured. Also wear mechanisms and lubricationmechanisms were analyzed.For the NiAl matrix self-lubricating composites containing Ti3SiC2-MoS2andTi3SiC2-nickel coated MoS2，the composite that containing nickel coated MoS2hashigher consistency，lower density and higher microhardness. The NiAl matrixself-lubricating composite containing Ti3SiC2and nickel coated MoS2exhibited thelower friction coefficients and wear rates over a wide temperature range，especially at400℃，it exhibited the best tribolgical properties.For the NiAl matrix self-lubricating composites containing Ti3SiC2-nickel coatedMoS2，the wide temperature range self-lubrication properties were realized by MoS2play a role of lubrication at low and medium temperatures，as well as Ti3SiC2at hightemperatures. The tribological properties of NiAl base self-lubricating compositeswere effectively improved by taking advantage of the synergetic lubricating actions ofTi3SiC2and MoS2. The friction coefficients of NiAl matrix self-lubricatingcomposites with5wt.%Ti3SiC2and5wt.%nickel coated MoS2decreased to the lowest value over a wide temperature range．For the NiAl matrix self-lubricating composites containing Ti3SiC2-nickel coatedMoS2，at different working conditions(temperature，sliding speed，load)，the frictioncoefficients of the composite decreased at first and then increased with the increase intemperature，while the wear rates increased with the increase in temperature，and thefriction coefficients of the composite decreased to the lowest value at400℃；thefriction coefficients of the composite increased at first and then decreased with theincrease in the sliding speed，the wear rates of the composite decreased at first andthen increased with the increase in the sliding speed. When the sliding speed is0.6m/s，the friction coefficients increased to the highest value and the wear ratedecreased to the lowest value. The friction coefficients of the composite decreasedwith the increase in load and the wear rates increased with the increase in load.