| To study the spalling failure mode of aeroengine ball bearings, atomic emission spectroscopy, automatic wear particle
analysis, ferrography, and energy-dispersive X-ray spectroscopy analysis were used to analyze the number, size, morphology, and composi?
tion of the wear particles in the lubricating oil from the equivalent accelerated test of ball bearings. The results show that the metal particle
contaminants lead to the initial fatigue spalling of the bearing. The characteristic particles of the ball bearing spalling were rolling fatigue
particles and spherical particles. The characteristic particles of neck bushing fretting wear were black iron oxide and red iron oxide
particles. Approaching bearings failure, the mass fraction of iron element in the lubricating oil increased from 7.49×10 -6 to 21.74×10 -6 , the
number of characteristic particles also increased sharply from 48.9/mL to 1433.8/mL, with the size of particles distributed mainly in the
range of 25 to 50 microns. The presence of metal particle contaminants accelerated the contact fatigue spalling of the raceway of the load-
bearing inner half ring. After the raceway spalling to a certain extent, the fretting wear occurred at the interface between the bushing and
the inner half ring under the combined effect of axial force, friction, and preload, which further aggravated the fatigue spalling of the
raceway and ultimately led to the failure of the ball bearing. |