Properties of Journal Bearing Materials That Determine Their Wear Resistance on the Example of Aluminum-Based Alloys

Potential relations of tribological characteristics of aluminum antifriction alloys with their compositions and mechanical properties were investigated. In this regard, the properties of eight aluminum alloys containing tin from 5.4% to 11% doped with lead, copper, silicon, zinc, magnesium, and titanium were studied. Mechanical properties such as hardness, strength, relative extension, and impact strength were analyzed. Within the tribological tests seizure load and wear of material were evaluated and secondary structures were studied afterwards. The absence of a definitive correlation between tribological behavior and mechanical properties was shown. It was determined that doping tin over 6% is excessive. The seizure load of the alloys increases with the magnesium content. Secondary structures of the alloys with higher wear rates contain one order less magnesium and tin.

Relationship of Secondary Structures and Wear Resistance of Antifriction Aluminum Alloys for Journal Bearings from the Point of View of Self-Organization During Friction

The paper investigates the relationship between the tribological properties/compositions of new aluminum antifriction alloys and compositions of the secondary structures formed on their friction surfaces. Eight alloys with various compositions have been analyzed. The elemental compositions of the secondary structures on their friction surfaces have been determined. The relationship between the alloy secondary structure compositions with wear rate has been found. An attempt has been made to determine the secondary structure composition patterns based on the non-equilibrium thermodynamics and self-organization theory.

Aluminum casting antifriction alloys with increased capacity to adaptability of friction surfaces

The possibility of changing bronze in the manufacture of monometallic cast plain bearings with multicomponent aluminum antifriction alloys is considered. Due to alloying of aluminum with tin, lead, copper, zinc, silicon, magnesium and titanium, it was possible to create alloys with increased ability to adapt friction surfaces. According to laboratory tests, the main results of which are given in the article, it is proved that aluminum alloys on a complex of mechanical and tribotechnical properties are close or superior to the investigated bronze BrO4C4S17. Laboratory tests have shown the possibility of manufacturing monometallic plain bearings from experimental cast aluminum alloys, which by mechanical properties are not inferior to the most solid among antifriction bronzes - bronze BrO4C4S17. On a complex of tribotechnical properties, experimental alloys exceed bronze. Due to their high-fusibility, lower density, lower cost and better workability, aluminum alloys have an almost 3-5-fold advantage over economic indicators before tin bronzes. The scope of the proposed alloys will be determined in the course of bench and operational tests. To date, an experimental batch of monometallic bearings of turbochargers TK 33N-02 has been manufactured from the alloy of the AO6S3M4CT series of “Spets Dizel Servis” (Novosibirsk), which successfully passed the bench tests. Bushings 3404.00.112, 3404.00.032 and bearings 3409.00.20, made from an experimental alloy, showed the possibility of replacing the standard bronze BrO8S12 in these turbochargers. It is advisable to carry out operational tests of bearing sleeves from the alloy AO6S3M4CT for turbochargers TK 34, TK 30 and TK 33, as well as bearing inserts for diesel locomotives.

NEW ALUMINUM ANTIFRICTION ALLOYS INSTEAD OF BRONZES FOR MONOMETALLIC BEARINGS OPERATING UNDER CONDITIONS OF BOUNDARY FRICTION

In the paper there is presented an investigation on the subject of the substitution of materials used for manufacturing monometallic one-piece sliding bearings. The most widely used material for their manufac-turing is bronze of BrO4Ts4$17 grade which has rather high values of antifriction and strength properties. A whole complex of materials based on aluminum alloys is under consideration. There were investigated eight experimental alloys different with chemistry. In the paper there is described a procedure for carrying out experimental investigations. The comparative tables of the influence of these or those elements upon tribological properties are shown. An evident advantage of aluminum alloys over a compared material – bronze of BrO4Ts4S17 grade is identified. The following tribo-technical properties of experimental alloys such as score-resistance, conformability, durability, frictional moment are considered. Key words: aluminum antifriction alloys, bronze, stress-strain properties, strength, hardness, tribotechnical properties, conformability, scoreresistance, durability, secondary structures.