Friction and wear properties of iron copper based powder metallurgy materials under braking conditions
-
摘要: 本文采用MM3000型摩擦磨损试验机,在两种不同面压和7种连续制动工况下分别测试铁铜基粉末冶金摩擦材料的摩擦性能和耐热性能,利用SEM和EDS研究两种不同转速下摩擦材料的磨损机理。结果表明:在线速度19.40 m?s-1,随着面压增加,摩擦材料动摩擦系数略有降低,在0.44 MPa下,动摩擦系数为0.267-0.312;在0.80 MPa下,动摩擦系数为0.258-0.308。在连续制动1工况(线速度19.40 m?s-1、面压0.44 MPa、单位面积制动能量268 J?cm-2)条件下,动摩擦系数波动较大;其它工况条件下,动摩擦系数波动较小;随着制动能量的增加,7种连续制动工况下平均动摩擦系数在0.300-0.334之间变化,动摩擦系数均在0.25以上,无明显衰退现象,表明铁铜基粉末冶金摩擦材料具有较好的耐热性能。在19.40 m?s-1工况下,铁铜基摩擦材料的摩擦磨损机理主要为磨料磨损及氧化磨损;在30.00 m?s-1工况下,铁铜基摩擦材料的摩擦磨损机理主要为疲劳磨损及氧化磨损。
-
关键词:
Abstract: The friction properties and heat resistances of iron-copper-based powder metallurgy friction materials were tested under two different surface pressures and seven continuous braking conditions by using MM3000 friction and wear testing machine, the wear mechanism of friction materials at two different speeds was studied by SEM and EDS. The results showed that at a line speed of 19.40 m?s-1, the coefficient of dynamic friction of the friction material decreases slightly with the increasing of surface pressure, which is 0.267-0.312 at 0.44 MPa and 0.258-0.308 at 0.80 MPa. The kinetic friction coefficient fluctuates more under the first continuous braking condition(Linear velocity 19.40 m?s-1, surface pressure 0.44 MPa, braking energy per unit area 268 J?cm-2); under other conditions, the kinetic friction coefficient fluctuates less. With the increasing of braking energy, mean kinetic friction coefficient under seven continuous braking conditions varied from 0.300 to 0.334, and the kinetic friction coefficient was above 0.25 without apparent decline, indicating that the iron-copper based powder metallurgy friction materials have better heat resistance. Under 19.40 m?s-1 working condition, the frictional wear mechanism of iron-copper based friction materials is mainly abrasive wear and oxidation wear; under 30.00 m?s-1 working condition, the frictional wear mechanism of iron-copper based friction materials is mainly fatigue wear and oxidation wear.
点击查看大图
计量
- 文章访问数: 138
- HTML全文浏览量: 25
- PDF下载量: 20
- 被引次数: 0