STUDY OF THE PROPERTIES OF COMPOSITE MATERIALS BASED ON ANTIFRICTION ALLOY B83

Abstract

The antifriction composite materials (CM) based on a B83 babbit alloy containing silicon carbide (SiC) and modifided shungite (MS) particles have been fabricated by hot pressing. The matrix powder was prepared using a planetary ball mill for processing chips obtained by machining of cast aabbitt. The resulting powder was sieved on a sieve analyzer. Powder mixtures for pressing were prepared by mechanical alloying in a planetary mill for 2 h at a stirring speed of 300 rpm. Composite semi-product was obtained by pressing the obtained powder mixtures on an ОМА mechanical press (P max = 150 kN) at pressure of 320 ± 5 MPa. Semi-products were heated in a muffle furnace in a mold at a temperature up to 300°C, kept at this temperature for 30 min and then pressed. We have shown that CM obtained using methods of powder metallurgy exhibit increased wear resistance at comparable values of the friction coefficient compared to the same properties of a cast alloy. Local elastic moduli of the obtained samples have been determined using the laser optoacoustic method based on the measurements of the phase velocities of thermo-optically excited longitudinal and shear ultrasonic waves. We have shown that B83-based CM containing MS (0.5 wt.%) and SiC (3 wt.%) can be recommended as an alternative to a B83 cast alloy due to the higher wear resistance compared to cast babbit. The friction surface of this composite material reveals the sliding areas and friction relief less distinct compared to the cast alloy.