Page 50 - 摩擦学学报2025年第4期

538 摩擦学学报（中英文） 第 45 卷

based composites reinforced with Cu-coated graphite exhibited the lowest friction coefficient (0.26), but their physical
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and mechanical properties and wear resistance [1.86×10 cm /(N·m)] were poor. Cu-coated Ti 3 SiC 2 could significantly
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improve the composites’ physical and mechanical properties as well as wear resistance [0.88×10 cm /(N·m)], while the
decrease in friction coefficient (0.49) was not significant. The copper-based composites reinforced with dual phases of
Cu-coated Ti 3 SiC 2 and graphite exhibited excellent physical and mechanical properties, friction reducing and wear
resistance performances. In addition, it was found that research had found that overly large graphite sizes could
adversely affect the local uniformity of the material, leading to internal damage within the graphite during testing and
subsequently reducing the physical and mechanical properties of the material. In friction tests, the use of smaller graphite
sizes (40 μm) enhanced the uniformity of the friction material structure, facilitating the even distribution of graphite
from the matrix to the friction contact surface, thereby improving the tribological properties of the material. Conversely,
larger graphite sizes were prone to flaking during the friction process, leading to three-body wear, which increased
the friction coefficient and wear rate. Composite materials reinforced with 40 μm copper-coated graphite and
Ti 3 SiC 2 exhibited superior physical and mechanical properties, with the lowest friction coefficient (0.35) and wear
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rate [0.54×10 cm /(N·m)]. During the friction process, graphite, due to its special lamellar structure, adhered easily to
the worn surface, providing lubrication, while Ti 3 SiC 2 oxidizes and decomposes to form a Ti-Si oxide film, thereby
reducing friction. The friction performance of the sample largely depended on the coverage of its lubricating film on
the friction surface. When the load too low, it's difficult for the sample surface to form a dense and continuous
lubricating film. Under the friction conditions of 80 N and 800 r/min, the copper-coated Ti 3 SiC 2 lubricant was
sufficiently enriched on the worn surface and fully oxidized, together with graphite, to form a smooth and well-dense
lubricating film, thus exhibiting excellent anti-friction and anti-wear properties. However, when the load and speed were
too high, the friction film was destroyed and cannot be replenished, resulting in a sharp increase in the friction
coefficient and wear rate of the sample.
Key words: friction; composite materials; Ti 3 SiC 2 ; graphite; lubricating film

摩擦材料是1种应用在动力机械上，依靠摩擦作用 因此，研究者们考虑在石墨铜基摩擦材料中添加其他
来执行制动和传动功能的部件材料 [1-2] . 由于具有良好的 增强相作为摩擦组元以弥补固体润滑剂的影响 [18-19] .
导热性、耐磨性及稳定的摩擦系数等优点，铜基复合材 目前，铜基摩擦材料中常用的摩擦组元有金属颗
料广泛用作摩擦材料 [3-4] . 制备高性能铜基摩擦材料的关 粒和陶瓷颗粒两大类 [20-21] . 以CrFe和镀铜石墨为增强
[22]
键在于保留铜基体优异性能的同时，还可以充分发挥 相制备的铜基摩擦材料有着高的硬度和抗氧化性 .
增强相的强化作用，因此，增强相的选择尤为重要 [5-6] . 但其磨损量大，在高温下容易出现热衰退，导致摩擦
石墨凭借其良好的导热、导电及自润滑性能，广 系数不稳定且噪声较大 . 而陶瓷材料增强的铜基复
[23]
泛用作铜基摩擦材料的增强相 [7-8] . 但是，由于石墨和 合材料噪音更小，且在宽温域内都表现出良好的摩擦
金属基体的密度差异较大导致二者结合较差，石墨很 学性能 [24-25] . Ti SiC 作为1种典型的三元层状陶瓷材
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[9]
容易从基体中剥离出来，起到磨粒磨损的作用 . 为了 料，具有高熔点、高热稳定性以及在高温下仍能保持
增强石墨和基体之间的结合，研究者们提出了许多对 较高的强度 [26-27] . 大量研究发现，将Ti SiC 作为增强相
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[12]
固体润滑剂表面进行改性的方法 [10-11] . 赵建华等 通 加入到铜基复合材料中可以提高材料的物理力学性
[28]
过研究，发现在石墨表面进行金属镀层处理可以提高 能 . 同样，Ti SiC 与铜基体界面结合较弱，摩擦过程
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石墨与铜基体之间的界面结合强度，使得复合材料的 易脱落产生磨粒磨损等问题，因此很多研究人员开始用
摩擦学性能得到明显改善. 此外，有研究发现石墨尺 金属修饰Ti SiC . 许少凡 通过化学镀覆技术对Ti SiC 2
[29]
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寸对复合材料的性能同样有较大的影响 [13-14] . 陈亚军 表面进行镀铜处理，并通过粉末冶金技术制备镀铜
[15]
等 研究了2~90 μm的石墨增强铜基复合材料，研究 Ti SiC -碳纤维-铜-石墨复合材料，结果表明：Ti SiC 2
3
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发现30 μm石墨铜基复合材料的力学性能和摩擦学性 表面镀铜后能够明显增强各组元间的结合并提高复
能最优. 但是单一石墨增强的铜基摩擦材料的力学性 合材料的力学性能.
[16]
能较差 ，且在高载和高转速条件下，样品表面温度 本文中以石墨作为润滑组元，Ti SiC 作为摩擦组
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升高，铜基摩擦材料中石墨的烧蚀会改变其表面的组 元制备铜基复合材料. 石墨在低载和低转速下的自润
[17]
成，材料的摩擦系数稳定性和耐磨损性能会因此下降 . 滑效果可以弥补Ti SiC 在中低温段的高摩擦系数等
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