| Currently, steel balls are mostly used as balls of the common rolling bearings,greater centrifugal force may emerge in condition of higher speed, which can result in increased frictional heat, thereby accelerate the process of bearing wear, reduce bearing life, cause serious bearing failure. The low density, corrosion resistance good tribological properties, easy processing before heat treatment make TiNi60 alloy a new material in high-speed bearings. Early results have indicated of the group Qunfeng Zeng et al., TiNi60 GCr15 alloy plate Pair in castor oil lubrication conditions after the run to the emergence of a low friction coefficient of 0.008 low friction phenomenon, analysis of the reasons may be the low-speed, light-load conditions easier low friction phenomenon. Thus, it is necessary through the load, speed, temperature, surface roughness and other factors studied conditions, to achieve ultra-low friction obtain optimal conditions for TiNi60 alloys used in low-friction bearing areas of great significance.Firstly, pair GCr15 steel balls and Si3N4 ceramic ball with TiNi60 alloy, study the tribological properties under dry conditions. Pair GCr15 ball with TiNi60 alloy, studied the tribological properties under three different lubricants.The experimental results indicate that the coefficient of friction and wear of Si3N4 Ceramic Balls and TiNi60 alloy pair are lower than GCr15 ball, which owns tribological properties at low light load condition; the coefficient of friction is far less than PAO oil and 1000# oil in castor oil lubrication, the wear of TiNi60 alloy and can reduced effectively. Therefore, castor oil was chosen for lubrication in the following research.Secondly, the problems in practical work of bearing, such as different load, speed, surface roughness, temperature were solved. GCr15 ball was paired with TiNi60 alloy, they were studied in the castor oil. Statistical analysis the relationship between different loads, frequency, temperature and the amount of wear, and the relationship between the kinematic viscosity of castor oil and the heating temperature by SPSS.The result shows that with the increase of load, the friction coefficient between 30-70N decrease, the relationship between the amount of wear and frequency meet the cubic equation. For different frequencies, with the increase of the reciprocating frequency, friction coefficient decreases, the wear increases gradually, but indistinctly. For different surface roughness, with the increase of surface roughness, the friction coefficient and wear increase not obviously. The relationship between kinematic viscosity of castor oil and the heating temperature of the power function. The relationship between the kinematic viscosity of castor oil and the heating temperature of the power function equation; For different heating temperatures, with the increase of the heating temperatures, the friction coefficient decreases, the relationship between the heating temperature and the amount of wear consistent with cubic equation.Followed were compared the samples at different times strengthen by supersonic particle bombardment, the results showed that:In this chapter, with the increase of the time, the Surface hardness of TiNi60 alloy increase, the maximum increase of 33%. With the increase of time the wear increases, but less than the untreated sample.Finally, based on the previous study, by TiNi60 alloy and high-speed steel pins Pair of various parameters to choose the best working conditions, at different sliding speeds repeatedly to achieve a low friction verified at low speed, light load, smooth surface conditions TiNi60 alloy prone to low friction. |
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