Brake disc coating made from an iron alloy composition and method for the production thereof

1. A wear-resistant layer made from an iron alloy composition, wherein the wear-resistant layer is a thermally sprayed coating on a brake disc in a region of a friction surface of the brake disc, comprising:

0.5% to 2% by weight C;

3% to 13% by weight Al; and

a residual portion of Fe and trace impurities to obtain 100% by weight.

2. The wear-resistant layer according to claim 1 , further comprising 0.5% to 5% by weight Cr and/or 0.05% to 0.5% by weight Si.

3. The wear-resistant layer according to claim 1 , further comprising:

0.5% to 5% by weight Mn; and/or

0.5% to 5% by weight Ni; and/or

0.1% to 3% by weight each of W, V, Nb and/or B.

4. An iron alloy composition of a wear-resistant layer on a brake disc brake surface, comprising:

0.8% to 1.2% by weight C;

6% to 8% by weight Al;

1.5% to 2.5% by weight Cr;

0.1% to 0.3% by weight Si; and

a residual portion of Fe and trace impurities to obtain 100% by weight.

5. The iron alloy composition according to claim 4 , further comprising 1.5% to 2.5% by weight Mn and/or 1.5% to 2.5% by weight Ni.

6. A brake disc, comprising:

a wear-resistant layer according to claim 1 ; and

an intermediate layer of a Ni alloy disposed between a base material of the brake disc and the wear-resistant layer.

7. A method for producing a brake disc, comprising the steps of:

roughening a brake surface of the brake disc to be coated to form a roughened brake surface;

applying a wear-resistant layer according to claim 1 to the roughened brake surface by a thermal spraying process; and

after the applying, improving ductility of the wear-resistant layer by thermal and/or mechanical after-treatment of the wear-resistant layer.

8. The method according to claim 7 , wherein the thermal and/or mechanical after-treatment comprises:

hammering or rolling the wear-resistant layer at a temperature in a range from 800° C. to 950° C.; and/or

rounding of brittle hard material phases of the wear-resistant layer at a temperature in a range from 850° C. to 950° C. over a period of 0.5 hour to 3 hours.

9. The method according to claim 7 , wherein:

a base body of the brake disc is produced from grey cast iron or cast aluminum;

the roughening takes place by particle beams, high-pressure water jets, or by a cutting tool; and

the thermal spraying process is atmospheric plasma spraying, flame spraying, high-speed flame spraying, or arc wire spraying.