Research: The physical, mechanical , thermal and frictional properties of two type C/SiC disks were investigated. One type is short fibre pressed C/SiC disk (CCB) which is popularly applied as a part of optional package on luxury vehicles and on refitted vehicles; The other type is fabric woven C/SiC disk (FWB), originated from C/C disk, which is based on preform body with carbon fibre on XY direction and pulp on Z direction, reversing the disadvantage of C/C disk’s application on vehicle such as big wear through abrasion and oxidation, low friction coefficient under cold and wet braking. Methodology: a) Physical test: Density, Hardness, Natural Frequency, etc. b) Mechanical test: Flexural Strength, Tensile Strength, Compression Strength, etc. c) Thermal test: Thermal Conductivity Coefficient, Specific Heat Capacity, Thermal diffusion Coefficient, etc. at 25, 200, 600, 1000 degree centigrade; d) Dynamometer test: Burst Test, AMS(constant braking) Test, Structure Strength Test, Thermal Crack Test, Thermal Deformation Test, etc. Results: a) Flexural Strength: FWB disk is 1.4 times bigger than CCB disk; b) Tensile Strength: FWB disk is 1.6 times bigger than CCB disk; c)* Specific Heat Capacity: FWB disk is 1.1 times (average) stronger than CCB disk on XY direction(friction surface) and 1.08 times (average) bigger on Z direction(thickness); *: The tested sample density of XY direction of FWB disk is 2.173 g/cm^3, and density of Z direction is 2.146 g/cm^3 ; density of CCM disk is 2.18 g/cm^3 on both direction. What new in the field: Compared with petrol vehicle, electric vehicle generates lower temperature during braking because of brake energy regeneration system. Due to the better specific heat capacity together with mechanical strength, FWB disk could have bigger vents or lower density design for electric vehicle to benefit weight loss and driving range increase. Limitations: a)FWB disk is manufactured with Chemical Vapor Deposition (CVD) process which costs longer term (around 30 days) than CCB disk. b)FWB disk must work with friction layer on the braking surface because of anisotropy. Conclusion: For electric vehicle, FWB disk is an option with lower weight, longer lifetime, more comfort (no DTV and judder generation) and lower CO2 emission (no brake dust). Due to its long term production term, comprehensive cost evaluation is required for an OEM project.
Ms. Xin Chen, RD Manager, Yantai Hi-Pad Brake Technology Co.,Ltd.; Dr.-Ing. ZiYue Shao, Material Engineer, Yantai Hi-Pad Brake Technology Co.,Ltd.