Description

Babbitt alloy is a kind of low melting point bearing alloy with hard particles distributed on soft matrix. There are three series of tin based, lead based and cadmium based. The representative composition (mass fraction) of tin based Babbitt alloy is: Antimony 3% ~ 15%, copper 2% ~ 6%, cadmium < 1%, and tin balance. Tin based and lead based bearing alloys with antifriction characteristics are also known as white alloys and black gold because of their white color. The solid phase point temperature of cast tin based Babbitt alloy ZSnSb11Cu6 is 240 ° C, the liquid phase point temperature is 370 ° C, and its service temperature shall not exceed 100 ° C. the friction coefficient is 0.005 in the presence of oil and 0.28 in the absence of oil.

The main alloy components are tin, lead, antimony and copper. Antimony and copper are used to improve the strength and hardness of alloys. The structural characteristics of Babbitt alloy are that hard phase particles are evenly distributed on the soft phase matrix. The soft phase matrix makes the alloy have very good embedment, compliance and bite resistance. After running in, the soft base is concave in the body and the hard points are convex, forming a small gap between the sliding surfaces, forming an oil storage space and a lubricating oil channel, which is conducive to friction reduction; The convex hard point plays a supporting role, which is conducive to bearing. Babbitt alloys are divided into tin based (see tin alloy) and lead based alloys. The latter contains 10% ~ 20% antimony and 5% ~ 15% tin. In order to prevent component segregation and refine grains, a small amount of arsenic is often added. The strength and hardness of lead based alloy are lower than that of tin based alloy, and the corrosion resistance is also poor.

Babbitt alloy is mainly used in the bearing bush, bearing, bushing and sleeve of large machinery main shaft. For example, cement machinery, steel machinery, chemical machinery, paper machinery, petroleum machinery, shipping machinery, compression machinery, coal mining machinery, mineral processing equipment, etc. can also be used in large machine tools to replace brass, and the effect is also very good. In addition to plain bearings, Babbitt alloy is often sprayed on steel or other substrates to make bearing shells because of its soft texture and low strength. In order to prevent component segregation and refine grains, a small amount of arsenic is often added.

Babbitt alloy can be divided into tin based alloy and lead based alloy. The strength and hardness of lead based alloy are lower than that of tin based alloy, and the corrosion resistance is also poor. Therefore, when customers use Babbitt alloy, they usually choose tin based alloy. The commonly used brands are zchsnsb11-6, zchsnsb8-4, zchsnsb8-8, etc. Although the performance of lead-based alloy is not as good as that of tin based alloy, many customers still choose to use it because it is more economical to use. The commonly used brands are zchpbsb16-16-2, zchpbsb1-16-1, etc.