Effect of New Design of the Laser Installation and Spraying Method on the Physical and Mechanical Properties the Inner Surface a Small Diameter Coated with 15Cr17Ni12V3F35ZrO2

Abstract

A unique controlled laser head with an adaptive module was developed to stabilize the trajectory of movement. The scientific and practical problem of developing a technology for restoring the inner surface of a small diameter up to ∅44 mm was solved by the introduction of a laser head. Adhesion was achieved by moving the laser along the vectors, forming a regular pyramid with opening angles at the top. High physical and mechanical properties of the restored pump surface were achieved by the laser technology when spraying powder composition 15Cr17Ni12V3F35ZrO2. The optimal values of the microhardness of the coating of 5000 MPa were achieved due to the optimal transition melting zone of 0.8 ÷ 1.45 mm; the laser radiation power density of 3 × 105 W/cm2; and the diameter of the focus spot of the laser beam of up to 1.3 mm. High corrosion resistance and tribology were achieved by an optimally matched distance of 10 ÷ 15 mm and a surfacing speed of 15 mm/s. Homogeneous spheroidized particles of the material were observed in the martensitic phase of the structure. The stable compression stresses in the phase structure during the laser deposition of zirconium dioxide were fixed at the level of 1.0 ÷ 1.5 N/m2, and the compression stresses were at the level of 0.2 ÷ 0.4 N/m2. A multifactorial experiment established the dependence of the coating hardness on the distance to the focal plane and the energy characteristics of the laser source, providing optimal laser parameters (area, pulse power, and duration).