For the normal contact mechanical seal
, the wear of the end face is one of the main causes of failure. The wear rate of the end face has an important influence on the life of the mechanical seal. At present, the study on the wear of mechanical seal faces mainly depends on the test method to observe the wear principle of the end surface, and the rate of wear is estimated according to the empirical formula. However, the wear performance test of materials is a basic research work which costs a lot of money and time. It is of great significance to study the wear characteristics and wear regularity of mechanical seal face and establish a reasonable theoretical model of end face wear, which is of great importance to rational design of mechanical seal structure, optimization of working conditions, selection of material evaluation, improvement of work performance, prolongation of service life and guiding wear test. The results show that the profile curves of the mechanical seal face are all isotropic.
Based on the wear theory and the fractal parameters with scale independence, the surface morphology and the change of the wear surface were characterized, and the fractal model of the mechanical seal face was established. According to the established model , the factors influencing wear rate of mechanical seal face are analyzed. The material of mechanical seal face usually adopts soft-hard group to form, the hard ring end face is much smoother than the soft ring end face, and the deformation and wear is very small, and it can be simplified as a rigid and ideal smooth plane. For the design and use of reasonable mechanical seal, the wear form of the soft end face is mainly the adhesive wear. When working, the contact between mechanical seal faces occurs on the asperity with a higher end face of the soft ring.
At the point of friction, deformation occurs at the contact point, resulting in adhesion. Subsequently, the adhesive nodes in the sliding are shear damaged by friction. This adhesion, destruction, and adhesion of the alternating process constitutes adhesive wear. There are many ways to calculate adhesive wear, but most of them are based on the Archard wear theory model.