Copper Powder has been widely used in the production of brake shoes, playing a crucial role in the performance of brake shoes friction materials when integrated into brake shoes mixtures and mixes.

Copper powder exhibits excellent thermal conductivity, with a value of around 400 W/(m·K). This high thermal conductivity allows it to efficiently dissipate the heat generated during the braking process. For example, in a high – speed braking test where the temperature at the friction surface of brake shoes without copper powder reached 450°C, the addition of 10% copper powder by weight in the brake shoes mixture reduced the peak temperature to 350°C. This significant temperature reduction helps prevent brake fade and ensures stable braking performance.

It also has outstanding electrical conductivity. The electrical resistivity of copper powder is extremely low, about \(1.7×10^{-8}\Omega\cdot m\). Although this property may not be directly related to the basic braking function, in modern vehicles with complex electrical systems, it can prevent the accumulation of static electricity during braking, which is beneficial for the normal operation of vehicle electronics.

The particle size of copper powder used in brake shoes production usually ranges from 10 – 50 micrometers. Smaller particles can better disperse in the brake shoes mixture, providing more uniform performance. Larger particles, on the other hand, can contribute to the mechanical strength of the friction material. For instance, a mixture with a proper proportion of different – sized copper powder particles can achieve both good heat dissipation and sufficient wear resistance.

As mentioned, the high thermal conductivity of copper powder is a major advantage. In continuous braking scenarios, brake shoes with copper powder can maintain a more stable friction coefficient. Tests have shown that after 20 consecutive heavy – duty braking cycles, the friction coefficient of brake shoes with copper powder remained at 0.38 – 0.42, while that of brake shoes without copper powder dropped to 0.25 – 0.30. This stable friction coefficient ensures reliable braking force, especially in emergency braking situations.

Copper powder can enhance the wear resistance of brake shoes friction materials. In a long – term wear test over 300,000 braking cycles, the wear depth of brake shoes with 15% copper powder was only 1.5 – 2 mm, while that of non – copper – containing brake shoes reached 3 – 4 mm. This means that the addition of copper powder can extend the service life of brake shoes by about 50 – 60%, reducing the frequency of brake shoe replacement and maintenance costs.

Copper powder has good compatibility with other components in the brake shoes mixture. It can be easily combined with various organic and inorganic materials, such as resins, fibers, and other friction – enhancing fillers. This compatibility ensures the stability and homogeneity of the brake shoes mixture, which is essential for consistent braking performance.

Copper is a relatively expensive metal, and the production of high – purity copper powder further increases the cost. Incorporating copper powder into brake shoes can raise the production cost by 30 – 50% compared to traditional friction materials without copper. This cost factor may limit its application in some price – sensitive mass – market brake shoes.

When brake shoes wear out, the copper powder in them is released into the environment. Copper is a heavy metal, and excessive accumulation in the environment can cause pollution. For example, in water bodies, high levels of copper can be harmful to aquatic organisms. As environmental regulations become stricter, the use of copper powder in brake shoes may face more challenges.

Copper powder is prone to oxidation in the presence of oxygen and moisture. Oxidation can reduce its thermal and electrical conductivity, as well as its effectiveness in enhancing the performance of brake shoes. Special anti – oxidation treatments are often required, which adds to the production complexity and cost.

In conclusion, copper powder offers significant advantages in terms of heat dissipation and wear resistance in brake shoes production. However, its high cost, environmental impact, and susceptibility to oxidation need to be carefully addressed. Brake shoe manufacturers must balance these factors according to the specific requirements of their products and the market they target.