欧美videos人牛交_亚洲激情乱码网站_五月婷婷精品视频在线播放_直接在线看黄AV免费观看

Physical properties: Black or black red; mohs hardness 5.5 – 6.0; density 4.9 – 5.2 g/ cm3

Physiochemical index: Fe3O4：Fe≥60%

Performance: It can comprehensively raise the friction performance of friction products, especially for improving the friction force under the condition of braking end speed. This material can obviously improve the heat-fading performance of friction materials, and can adjust friction coefficient under high temperature, as well as reduce high-temperature fading. Under high temperature, it can play the functions of cleaning friction opposing material and improving braking effect. It is usually used in composing brake shoe, as well as in producing high-end brake pad.