Using composite material as alternative material to cast iron in fabrication of disc brake rotor for race car: An essay for Mr. Murtadha Muhsin Date: 17/09/2020 | Views: 2170

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The automotive industry under enormous legislative weight needs vehicle emissions to be diminished. This has promoted the automotive manufacturing to find several various methods to minimize the mass of vehicle by utilizing lightweight material likes Aluminium metal matrix composite (AMMC). The replacement of the traditional cast iron disc brake rotor with an alternative AMMC is one of methods which has in recent times received great attention. The important issue associated with the utilize of Aluminium alloy in disc brake rotor was the softening and overheating of the material owing to it’s low melting temperature which is at (500°C).
Lotus Elise was the first passenger car with disc brake rotors manufactured from AMMC. The low car mass of the Lotus Elise (equivalent to 650kg) leads to sufficient performance of the disc brake rotor. Therefore, the primary goal was to utilize a lightweight disc brake rotor for small or medium passenger cars. Therefore, utilizing disc brake rotors manufactured from lightweight materials or its composites such as AMMC might be minimizing the weight of the conventional cast iron by two thirds (2/3), generally (3kg) for each rotor and minimizes the brake vibration and squeak.
Previously, the numerical analysis as well experimental analysis of lightweight disc brake rotors indicated that the Alumina layer covered wrought Aluminium alloy has a superior thermal properties and high tribological performance against wear than either coated or uncoated AMMCs. But the difference in thermal expansion coefficient between Aluminium and Alumina may limit their usage in this application because the high thermal expansion of Aluminium leads to failure of Alumina thin coated layer. Therefore, the utilization of AMMC reinforced by Alumina particles with high weight fraction was the best solution.
The extrinsic effect of ceramic reinforcement phase in AMMC has been useful in disc brake /pad brake tribocouple manufacturing industry. When the disc brake rotor slips on the brake pad, adhesive tribolayer are shaped on the surface at contacting region. The formation of this tribolayers enhances the wear resistance of disc brake rotor. The chemical composition of tribolayers is a mixture of oxides that formed owing to transmission the material from the brake pad onto the Aluminium composite disc during slipping.
Aluminium alloy matrix reinforced by ceramic phase like Alumina (Al2O3) and Silica (SiC) has been manufactured to advance prototype components of automobile such as a disc brake rotor and cylinder blocks for cars of four wheeler also two wheelers cars.
Some high silicon Aluminium alloys generally utilized to fabricate internal combustion engine pistons as well as cylinder heads, have a
thermal expansion coefficient as low as (16x10-6/K), while the coefficient is decreased to (12.2x10-6/K) in some AMMCs by adding 38wt. % ceramic reinforcement phases such as SiC or Al2O3