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| Calling News |
| Development and Research of high-lead bronze centrifugal casting technics |
| 2009-10-30 15:19:28 |
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(has been browse 119 times)
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Lead bronze is the alloy with lead added to copper base alloy. It mainly has two kinds. The first kind is not only added with superior lead, but also some tin and zinc. This kind is mainly used in the independent manufacture of axle bearing and axle sleeve. The second kind is lead bronze with only lead added. The content of lead is generally 30%, and the maximum can reach 45%. This kind is usually used to manufacture doubling alloy ( steel jacket of the outer layer, and lead bronze of the inner layer), which our factory doesn't manufacture.
The lead in lead bronze doesn't dissolve with the alloy. It is distributed in the copper uniformly in the form of indepent tiny granules, so it has the effect of keeping lubricating oil and reducing coefficient of friction.
The frictional coefficient of lead bronze is 0.004～0.008 (with lubricate), which is 1～4 times lower than other coppor alloy. Lead bronze axle bearing can work under the pressure of 60～100Mpa, and withstands strike and high load. It can work under the speed of 8～10 meters per second. It is also heat-resistant and antifatigue because its heat conductivity is four times than tin bronze and six times than babbit alloy. It is not easy to crack or cohere under strong strike and heavy load. Especially when the lubricating oil way is choked and not detected in time, causing the axle bearing to be too hot and reach higher than 300℃, the lead will be melted and escaped from the axle bearing, which has lubrication in short time. This will protect the axle bearing and axis from damage. When detected, take the axis out and clear the lead. After the lead escapes from the axle bearing, it leaves tiny oillet there, which has the effect of oil impregnated bearing after being cleaned and fueling charging.
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