Changes and Development of Semi-Metallic Friction Materials
Semi-metallic brake pads are a new type of friction material developed on the basis of organic friction materials and traditional powder metallurgy friction materials. Metal fibers are used to replace asbestos fibers. It is a non-asbestos friction material developed by the American Bendis company in the early 1970s. Material.
"Semi-metal" hybrid brake pads mainly use coarse steel wool as the reinforcing fiber and important compound. Asbestos and non-asbestos organic brake pads (NAO) can be easily distinguished from the appearance (fine fibers and particles), and they also have certain magnetic properties.
The United States, Europe, Japan and other countries have promoted the use of semi-metallic friction materials on a large scale since the 1960s. The wear resistance of the semi-metal sheet is more than 25% higher than that of the asbestos sheet, and it currently occupies a dominant position in the brake pad market in my country. In most cars in the United States, especially cars and vans, semi-metallic brake linings account for more than 80%.
However, the product also has the disadvantages of steel fibers being easy to rust, high thermal conductivity, high hardness, and high density.
Although "semi-metal" has many shortcomings, it is still the first choice for automobile brake pads due to its good production stability and low price. However, as the international market is increasingly favoring asbestos-free and metal-less environmentally friendly friction materials, this limits the content of harmful metal components and copper in friction materials. It can be seen that "semi-metal" friction materials will also gradually withdraw. stage of history.
