Production and Testing of Aluminum Metal-Matrix Composite Brake Rotors for High Performance Applications

1. Production and Testing of Aluminum Metal-Matrix Composite BrakeRotors for High Performance Applications Graham Withers – Cyco Systems Jue Sun – Shanghai Sanji Die Casting Machinery Co. Stephen Midson – The Midson Group

2. Brake rotor for US sports car 355 mm diameter by 32 mm thick Produced from ULTALITE Al-MMC For high performance applications Objective Patent pending

3. ULTALITE Al-MMC • ULTALITE is an Al-MMC produced by mixing classified fly ash particles into an aluminum casting alloy • Fly ash is generated during the combustion of pulverized coal at power stations • Fly ash is low cost with abundant supplies Classified fly ash

4. Why Use Fly Ash? • Fly ash is considerably cheaper than alternate ceramic materials used in Al-MMCs • Fly ash significantly reduces the material cost of Al-MMCs • Crucial for automotive applications

5. Classification of Fly Ash • Raw fly ash contains a range of material (less than 0.1 µm to greater than 100 µm) • Solid spheres (SiO2/Al2O3) • Hollow spheres (SiO2/Al2O3) • Irregular shaped particles (amorphous SiO2) • Extraneous oxides (CaO, Fe2O3) • Un-burnt carbon • A commercial classification process is used to extract the solid spheres

6. Size Distribution of Raw and Classified Fly Ash • Raw fly ash • Majority between 0.5 and 200 µm • Classified fly ash • Majority between 10 and 45 µm Raw Classified Differential Volume (%) Differential Volume (%) Cumulative Volume (%) Particle Diameter (µm) Classified particles are called “Ceramatec

7. Production of ULTALITE Al-MMC • ULTALITE is produced by stirring Ceramatec particles into molten aluminum alloys • A356 (Al-7.0%Si-0.3%Mg) • A380 (Al-8.5%Si-3.5%Cu) • Density of Ceramatec particles is 2.4 g/cm3 • Similar to molten aluminum • Allows easy mixing of Ceramatec into molten aluminum • Uniform particle distribution • No gas entrapment • No surface defects Microstructure: A356-20% Ceramatec

8. Properties of ULTALITE Al-MMC Mechanical Properties Wear Properties

9. Brake Dynamometer Testing • Dynamometer testing has been performed on 200 mm diameter brake drums squeeze cast from ULTALITE Al-MMC

10. Brake dynamometer testing carried out at Brake Testing International (BTI), UK AK Master Tests in accordance with SAE J2522 Standard NAO factory OEM linings were utilized Drum/lining combinations used for the tests Cast Iron/Nisshimbo lining ULTALITE Al-MMC/Nisshimbo lining ULTALITE Al-MMC/DON#8259 lining Testing Conditions

11. AK Master Test is normally temperature based Requires the brake drum to attain a specified initial brake drum temperature (IBT) Substantially higher number of stops required for Al-MMC drums due to high heat dissipation, which leads to unrealistic high brake lining temperatures AK Master Test – Time based Time durations used for stops associated with attaining the IBT for cast iron drums were utilized for Al-MMC drums Provides conditions similar to tests conducted on cast iron drums in accordance with SAE J2522 Standard AK Master Test

12. Lower temperatures for Al-MMC drums Higher brake factors for Al-MMC drums Fade Segment – 6.9 Brake factor Pressure Temperature Cast Iron/Nisshimbo ULTALITE/Nisshimbo Brake Appl. No. Deceleration = 0.4g, Velocity = 100 → 5 km/h

13. No evidence of brake fade in the Al-MMC drums during recovery More consistent & smoother brake performance in Al-MMC drums Recovery Segment – 6.10 Cast Iron/Nisshimbo ULTALITE/Nisshimbo Brake Appl. No. Brake Appl. No. Pressure = 30 bar , Velocity = 80 → 30 km/h

14. As anticipated, higher wear is evident in the leading shoes During high temperature test sections, lining wear in Al-MMC drums decreased substantially (-> 225ºC section) Overall lining wear with Al-MMC drums was less than for cast iron drums Lining Wear Characteristics

15. ULTALITE 55% 0% CAST ULTALITE CAST 144 Hrs PRE-TEST Corrosion Resistance ULTALITE vs. Cast Iron Brake Drum • Both cast iron and Al-MMC brake drums were tested under identical salt spray testing conditions (in accordance with ASTM B117) • Approx. 55% of the surface on cast iron brake drum was covered in rust • Only minor corrosion on Al-MMC brake drum

16. Brake Rotors – US Sports Car Targets: Direct replacement of OEM cast iron rotor with aftermarket lightweight Al-MMC rotor Produced from ULTALITE Al-MMC Envelope of rotor remains same Technology applicable to other OEM applications Patent pending

17. Brake Rotors – Innovative Design Surface Venting Vented to maximize heat loss Surface venting allows production using metal tooling Multi-direction Venting pattern allows rotors to be used on either side of vehicle Minimize warping Surface area of friction blocks reduces towards circumference Shallow vents Vents lined up inside-to-outside Vents curved For progressive contact of brake pads Patent pending

18. Brake Rotors – Light Weight ULTALITE A356-20% Ceramatec particles ULTALITE A380-20% Ceramatec particles Current cast iron rotor – 12 kg ULTALITE Al-MMC rotor – 6.2 kg Primary weight savings per rotor – 5.8 kg Primary weight savings for four rotors – 23.2 kg Total primary + secondary weight savings – 47.3 kg MIT analysis suggests that consumers will pay an additional $22.50 per rotor for the associated fuel savings

19. Brake Rotors • Rotors are produced by squeeze casting • 1000-ton vertical-injection squeeze casting machine • Squeeze casting • Uses high quality Al-MMC • Slow injection speed • High intensification pressure • Metallic dies • Extremely high quality castings, with excellent properties and no residual porosity

20. Simulation - Die Filling Castings made with vertical orientation Gated at lower edge Upward flow minimizes turbulence during die filling Minimize porosity and oxide entrapment

21. Summary & Conclusions • A project is ongoing to produce high performance and OEM replacement brake rotors from ULTALITE Al-MMC • The low-cost Al-MMC is produced using Ceramatec particles classified from fly ash • The rotors will be produced by squeeze casting • Dynamometer testing has demonstrated that the ULTALITE Al-MMC has excellent braking performance, and can be used with standard factory brake pads and linings

22. Contact Information • Cyco Systems • Graham Withers • 888-540-4722 • gwithers@ultalite.com • Shanghai Sanji Die Casting Machinery Co • Trevor Tan • 510-676-8655 • szsanji@yahoo.com • The Midson Group • Steve Midson • 303-868-9766 • steve@themidsongroup.com