Effect of Laser Processing on the Qualitative Parameters of Protective Abrasion-Resistant Coatings

The wear of centrifuge screws, common components in industrial and municipal wastewater treatment plants, is studied. The TN-20 tungsten-free hardmetal serves for protecting screw flights against abrasive wear. The 12Kh18N10T steel is primarily used in the manufacture of centrifuge screws. A combined technique of depositing protective wear-resistant coatings is proposed. The technique includes electrospark deposition of a T15K6 hardmetal electrode, application of a metal polymer material (MPM), and final laser processing. To reinforce the MPM, small portions of a VK6 hardmetal mixture were added to a two-component epoxy system filled with ferrosilicon and thoroughly stirred. The reinforcement content was ~60%. This technique produces coatings up to 600 μm thick, with 7.3–10.0 GPa microhardness and 100% continuity. Abrasive water jet tests of the 12Kh18N10T steel samples with protective coatings show that their wear resistance is 7.5 times higher than that of the uncoated samples.