Kinematic characteristics of ultrasonic surface treatment

Abstract

We investigate the kinematic characteristics of ultrasonic surface-plastic deformation when the oscillations are introduced in the direction tangential to the treated surface in order to assess the potential of this method for treating parts made of metals and alloys of various hardness. The kinematic parameters (trajectory, velocity, acceleration) of ultrasonic surface-plastic deformation were calculated in a rectangular coordinate system. Analytical dependencies were obtained for the trajectory length, resulting velocity, and acceleration as functions of the constituent types of motion (rotational, translational, oscillatory). The obtained equations and their graphical solutions allowed us to establish that, under ultrasonic surface-plastic deformation, the indenter moves along a complex trajectory with a variable velocity and acceleration. It is shown that the translation of ultrasonic oscillations to the indenter determines the complex nature of its movement, which differs significantly from that in the diamond burnishing method. In this case, the process parameters (velocity and acceleration) change according to a cyclic (sinusoidal) law, the periodicity of which depends on the frequency of ultrasonic oscillations and determines the final state of the treated surface. According the obtained results, the change in the input direction of ultrasonic oscillations (from normal to tangential) ensures the possibility of changing the contact condition from cyclic to constant, thereby affecting the deforming force during processing. It was found that the angle of oscillation input relative to the main velocity vector is a technological parameter significantly affecting the kinematic characteristics. An assumption is made about the possibility of using the tangential pattern of ultrasonic surfaceplastic deformation for parts made of metals and alloys of various hardness.