Analysis of Rivet Head Falling off of Bearing

The aluminum rivet heads of bearing fell off during transportation and service process. The macroscopic and microscopic morphology and microstructure of the fracture and cross section of the rivet which has fallen off were analyzed and measured by the stereo picroscope, metallographic microscope and scanning electron microscope. The results show that the rivets were unilaterally detached, and they were located on one side of the original riveted head. The fracture type was brittle intergranular fracture, and the reason was related to the brittle interface caused by the secondary solution recrystallization of the original riveting molding head and the stress concentration vacancy generated in the riveting process. It is recommended to use the double-sided riveting method to ensure the consistency of the riveting state of the rivet heads on both sides of the bearing, and optimize the bearing riveting process to improve the bearing riveting quality.