Development of an innovative hybrid brake disc: INNOBRAKE. Dipl.-Ing. Ralf Kaiser, Foundry Institute, TU Bergakademie Freiberg

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1 Development of an innovative hybrid brake disc: INNOBRAKE Dipl.-Ing. Ralf Kaiser, Foundry Institute, TU Bergakademie Freiberg

2 introduction structure 1. functional principle INNOBRAKE 2. research project 3. material study of the steel inlays 4. study of the compound 5. conclusion 2

3 1. functional principle of INNOBRAKE

4 1. functional principle of INNOBRAKE requirements on brake discs brake discs are highly stressed components powerful brake for several times thermal load up to 800 C problems friction ring cannot expand freely brake warping brake power and brake comfort are reduced brake discs are rotary masses thermomechanical stresses corrosion 4

5 1. functional principle of INNOBRAKE reducing brake warping create additional adverse tension increased weight no additional costs problem not solved, but still with 99 % market share 5

6 1. functional principle of INNOBRAKE reducing weight and brake warping composite brake disc reducing brake warping decreased weight high manufacturing costs, no large scale production 6

7 1. functional principle of INNOBRAKE concept INNOBRAKE no brake warping lightweight low cost 7

8 1. functional principle of INNOBRAKE design of INNOBRAKE disc friction ring chamber steel inlay 8

9 1. functional principle of INNOBRAKE SHEET CAST disc brake disc based on the patents of Sheet Cast Technologies GmbH first prototypes tested on dynamometer basic metallographic research brake disc designed as a modular system thereby: scalable in size usable for trucks, rail vehicles and electric vehicles production in different material combinations are possible 9

10 1. functional principle of INNOBRAKE manufacturing process of INNOBRAKE disc 10

11 1. functional principle of INNOBRAKE SHEET CAST disc standard brake disc low-cost (20 ), high thermal stresses (brake warping) 10 kg (based on 16 inch disc) pin brake disc expensive (50 ), lower thermal stresses, acceptable brake warping 8,5 kg Innobrake disc inexpensive (25-35 ), least brake warping 7,5 kg - 8,5 kg 11

12 2. research project

13 2. research project research project INNOBRAKE promoted project by BMBF and PTJ runtime: november 2011 october 2013 project partners: foundry institute, TU Bergakademie Freiberg SHEET CAST Technologies GmbH, Ingolstadt supported by: 13

14 2. research project research project INNOBRAKE project content design, optimization and manufacturing of prototypes testing on dynamometer and vehicle study of recasting steel inlays in cast iron analysis and optimization of the composite longterm study (thermal damage, corrosion) material studies of the steel inlays 14

15 3. material study of the steel inlays

16 3. material study of the steel inlays S700MC - facts thermomechanical rolled fine-grain steel chemical composition (DIN EN ) C Mn Si P S Al (min.) Nb V Ti S700MC 0,12% 2,10% 0,60% 0,025% 0,015% 0,015% 0,09% 0,020% 0,22% starting from 580 C loses strength (DIN EN ) ferritic-bainitic microstructure R e > 700 MPa R m 750 MPa 950 MPa A 5 12% 16

17 tensile strength [MPa] 3. material study of the steel inlays static parameters hot tensile tests temperature [ C] delivery condition 50h temper 17

18 yield [MPa] 3. material study of the steel inlays static parameters 750 tempering C 250 C 500 C 625 C time [h] 18

19 3. material study of the steel inlays microstructure etched with Nital at 500x magnification ferrite 750 C, 5h delivery condition 750 C, 50h 19

20 4. study of the compound

21 4. study of the compound linearized model for studys at the foundry institute adapt to dimensions of INNOBRAKE disc model for tensile tests, corrosion tests, study of composite, coating and metallgraphy 21

22 4. study of the compound coating coat of sand cores improve surface quality affect heat transfer between the melt and form constraints inherent inlay are wetted by coating effect on compound? corrosion problems? improvement of surface necessary? using Arkopal-coating Suspension of aluminum silicates, graphite and iron oxide in water corrosion at the inlay 22

23 temperature [ C] 4. study of the compound extending the casting temperature inlay casting time [s] 23

24 4. study of the compound influence of the coating Due to the low temperature in the inlay creates a form-fitting and no material connection different thermal conditions in complete brake disc 5 mm without coating R Z = 6,4 µm 5 mm with coating R Z = 10,3 µm 24

25 4. study of the compound linearized model tensile test pull out of the inlay to visible damage at the cast iron F max [kn] without coating 27,6 with coating 30,4 coating increases tensile strength presumption: Surface roughness in the compound zone 25

26 4. study of the compound influence of the coating Roughness of the casting surface improves by coating R Z = 25 µm (coated) R Z = 45 µm (uncoated) without coating R Z = 45,3 µm with coating R Z = 25,4 µm 26

27 4. study of the compound metallography steel inlay cast iron 27

28 4. study of the compound metallography 28

29 5. conclusion

30 5. conclusion ongoing and planned studies corrosion tests in cooperation with Daimler AG thermomechanical fatigue of cast iron and compound opportunities for material connection compound quality to total brake disc necessity and the influence of coating testing on dynamometer and vehicle 30

31 Thank you for your attention! If you have any further questions, please do not hesitate to contact us. Visit our stand E52 at hall