Technical Articles

Cast iron and carbon are the two main materials used to make a brake disc. The benefit of Carbon is that it has a high thermal resistance and is lightweight. The downside is that Carbon is expensive, so it is used mainly by high budget racing teams. Cast iron is the more commonly used base material. There are three types of cast iron, each type has different graphite composition; grey cast iron, CV cast iron and ductile cast iron. Grey cast iron (flakes graphite cast iron) has excellent processibility and anti-abrasion capability. Grey cast iron has the advantage of being easily mass-produced, making it the most commonly used by discs manufacturers. The drawback is that it could be deformed or cracked under repeated sharp changes in temperature in the high temperature range (about 800℃). Ductile cast iron is an excellent material. The tensile strength of ductile cast iron is equal to that of steel. Ductile cast iron also has an high anti-heat capacity (stability against expansion and contraction). Unfortunately, it has low surface hardness, which can cause abnormal wear and/or abnormal heating due to its high exothermicity, if the material is used for brake discs. CV cast iron (Compact Vermicular cast iron) has an intermediate character between grey cast iron and ductile cast iron. The quality control of CV cast iron during the manufacturing process is extremely difficult, so the quality varies. Sometimes its closer to grey cast iron but other times is closer to ductile cast iron. After extensive testing, grey cast iron with special additives are being used in DIXCEL brake discs. OEM Products often use grey cast iron with FC150～200 (FC is numeric representation of the strength of cast iron). DIXCEL uses grey cast iron with FC200～250 for higher durability. After extensive research and development, DIXCEL developed a disc which has special additives to strengthen the disc’s vulnerability to sharp temperature changes in the high temperature range. The superior precision and balance of the disc goes without saying.