||Bolt Size mm
Zinc alloy bearing knowledge- new bearing alloy material
High aluminium zinc base alloy is a new type of gravity casting zinc-base alloy series, represented by ZnAl27Cu2Mg namely ZA27-2 and derivative of high al-zn base alloy, as a new type of bearing alloy has been widely replaced part of babbitt and bronze, used to make all kinds of bearings, bushings, skateboarding, slider, worm gear and transmission nut anti-friction wear-resistant parts.
To join other elements for zinc based alloy. Often add alloy elements are aluminum, copper, magnesium, cadmium, lead, titanium, etc. Zinc base alloy low melting point, good liquidity, easy fusion welding, brazing and plastic processing, in the atmosphere corrosion, deformed material easy to recycle and remelting; But low creep strength, prone to natural aging changes size. The melting method, die casting and pressure processing timber. According to the manufacturing process can be divided into cast zinc-base alloy and
deformation of zinc base alloy.
Compared with babbitt
In addition to have a significant price advantage, but also has a higher proportion of strong toughness, lower and wider application range and so on.
Compared with the bronze
1. The strength, hardness and allowable pressure aluminum bronze and widely than tin, lead, etc., allowable speed. Can completely meet the wearing parts such as independent anti-friction bearing conditions of use.
2. Strong affinity for lubricating oil, the better lubricity, plus its metallurgical properties, low melting point, not easy to metallurgical bonding with steel shaft), so using the tackiness resistance is strong, anti-friction wear-resisting properties become more prominent.
3. Low friction coefficient, wear small, and long service life. Under the same conditions of use, generally in copper tile 1 times above, which reduces the parts purchasing cost.
4. Thermal conductivity big (ZZnAl27Cu2Mg lambda = 125; ZCuAl10Fe3 lambda = 59), fast heat dissipation, the grinding temperature rise is slow and low friction pair has better protective effect.
5. Low density materials (ZZnAl27Cu2Mg rho = 5 g/cm3), product quality is light, light in weight is the same as specifications, with a third), installation, maintenance more easy and convenient.
6. With high damping characteristics, vibration noise.
Save cost advantage is obvious
Zinc base alloy has the superior mechanical properties not only, more high cost performance.
The lubrication recommendations
A. normally, appropriate USES VG680 dynamic viscosity of lubricating oil in summer, winter appropriate USES VG460 dynamic viscosity of the lubricants. At the same time, also want to consider in using environment and the regional difference and high attention whether the thickness of lube film lubrication requirements.
B. although high aluminium zinc base alloy bearing more than bronze bushing to the requirements of the lubricating oil with low, but because of the development trend of the modern equipment is toward large load, high efficiency, long service life direction, so we must update the concept of lubrication, in order to ensure the machine more safety operation, suggest using high quality lubricating oil containing extreme pressure and wear resistant additives.
The characteristics of the zinc base alloy. The casting performance is good, can die casting precision of complicated shape and thin wall parts, casting a smooth surface.
C. for surface treatment: electroplating, spray, spray paint.
D. On the melting and casting no iron, no corrosion pressed, non-stick mold.
E. Have a good room temperature mechanical properties and wear resistance.
F. Low melting point, melts at 385 ℃, die-casting molding easily.
In use process must pay attention to the problem:
1, Aging effect
Organization of zn-base alloy is mainly composed of zinc-rich solid solution containing Al and Cu and rich Al solid solution containing zinc, their solubility with temperature down. But as a result of die casting solidification speed, thus to room temperature, the solubility of solid solution is greatly saturated. After a certain period of time, this kind of phenomenon of supersaturated gradually lifted, and make the casting to slightly changing the shape and size.
2, The poor corrosion resistance.
When the impurity elements in the alloy composition of lead, cadmium, tin, exceed standard, cause a deformation of the casting and aging, characterized by swelling volume, a significant reduction in the mechanical properties especially the plastic, after a long time and even rupture.
Lead, tin, cadmium in the zinc base alloy solubility is small, and focused on the grain boundary as cathode, rich aluminum solid solution as the anode, in the presence of water vapor (electrolyte), led to intercrystalline electrochemical corrosion. Die casting due to intergranular corrosion and ageing.