Surface Properties of High-Strength Cast-Iron Parts with Wear-Resistant Composite Coatings Synthesized by Electrospark Alloying Method. Pt. 1. Specific Aspects of Mass Transfer; Geometric, Topographic, and Mechanical Charcteristic Features of Strengthened Surfaces

ПОВЕРХНЕВІ ВЛАСТИВОСТІ ВИСОКОМІЦНИХ ЧАВУННИХ ДЕТАЛІВ 429 changed by destruction of the applied layer, i.e., ∆mк may become negative.With an increase in the discharge energy (Wp), the mass-transfer process increases, but the process of the applied coating layer destruction begins earlier, while the roughness of the coating increases and its continuity decreases.At Wр = 0.55 J, the ESA process, which is carried out by the ETs made by the PM method and having the composition of 90% ВК6 (VK6) + 10% 1M and with 1M of 70% Ni, 20% Cr, 5% Si, 5% B, as well as by the ETs made of ВК6 (VK6) hard alloy and Х20Н80 (Kh20N80) nichrome wire, with the special technological saturating media СТНС (STSM) of the compositions of 0.5% Si + 0.5% B + 2% Cr + 7% Ni + 90 petroleum jelly and 5% Si + 5% B + 90% petroleum jelly, respectively, for the samples made of the ВЧ50 (VCh50), and the above ESA process are accompanied by decreasing yield strength and strength limit and increasing the relative elongation (δ).The roughness of the surface layer increases, and the continuity (S) of the coating decreases.After non-abrasive ultrasonic finishing, the yield strength and strength limit increase, and δ decreases.Surface roughness decreases and S increases.As Wp increases from 0.55 to 1.3 and 3.4 J and, at using the same ETs, yield strength and strength limit decrease, and δ increases, the roughness of the coating increases, and S decreases.After the next non-abrasive ultrasonic finishing, the yield strength and strength limit increase, and δ decreases, surface roughness decreases and S increases.