Study On The Tribological Characteristics Of Copper-bismuth With Silver Bearing Materials In Different Working Condition

In the sliding bearing material, it’s extensive for using lead element. However, lead isa toxic element. With the improvement of people’s health and environmental awareness,lead-free product requirements become more stringent. Low melting point Bi can bereplaced with lead for friction and anti-adhesion. However, due to Bi brittle and easy tofall off, it affect the wearing of Copper-based bearing material. To compensate for thedefects that arising by Bi. Lead-free copper-bismuth bearing materials add in a litter ofAg element, which to further improve the tribological properties of lead-free copper-bismuth bearing material. For clarity effect and mechanism with Bi and Ag element howreduct the friction and wear of copper-bismuth with silver bearing materials. In thispaper, three materials as the object of study, and these materials is copper-base alloymaterial, copper-bismuth bearing materials and copper-bismuth with silver bearingmaterials. Experiments sample preparation process is using conventional powdermetallurgy techniques. On the basis of tests related to the mechanical properties, it studythe tribological properties of several copper-based bearing materials under differentworking conditions. Combined with micro-test analysis methods discussed the frictionand anti-adhesion mechanism of copper-bismuth with silver bearing materials.Research shows that when the amount of drip is less, friction and wear properties ofcopper-base alloy material is relatively poor, friction and wear properties ofcopper-bismuth bearing materials and copper-bismuth with silver bearing materials isrelatively good. Copper-bismuth with silver bearing materials7#has the best frictionand wear characteristics. Add the right amount of silver has improved the friction andanti-adhesion of copper-bismuth bearing materials. When a certain increases amounts oflubricating oil, oil film will be instability and it will be affects Bi, Ag precipitation, atthe same time it lead to reduced tribological characteristics. Continue to increaselubricating so that friction interfacial has adequate oil (drip quantity:45drops/min).The major role of reducing friction in friction and wear process is lubricating oil. Itmakes running smoothly, low coefficient of friction, a small amount of wear. Tribological properties of several materials is closer. lead-free copper-bismuth withsilver bearing materials has better properties of friction and anti-adhesion at Poorlubrication conditions.Since the low melting point component Bi easy to precipitate to surface friction dueto the frictional heat and the extruding in copper-bismuth bearing materials, it playsproperties of friction and anti-adhesion. But Bi has characteristics of brittle. The Bi thataccumulate in the friction surface is easy to fall off the surface of copper base, so thatthe wear resistance of the material is reduced. Ag and Bi can form eutectic structure. Agcan pinning effect on Bi, so that it can Enhance the binding force between Bi andcopper matrix, and it can slow Bi shedding from the surface of copper-based alloys. Itmeans that Bi and Ag have synergies in improving tribological properties of materials atthe friction surface.