Component of a brake for a vehicle and method for its manufacturing
A component of a brake for a vehicle, having a metallic base body with a surface provided with a coating which includes an intermediate layer lying on the base body and a covering layer lying on the intermediate layer. The covering layer is formed from a stainless steel matrix with hard material particles embedded therein. The hard material particles embedded in the stainless steel matrix have an average grain diameter of 10-125 μm and have a non-melted core region consisting of uninfluenced material of the hard material particles, which core region is surrounded at least in sections by a mixing zone formed from material of the stainless steel matrix and material of the respective hard material particle, via which mixing zone the hard material particles are in each case materially bonded to the stainless steel matrix. Also, a method by which a component coated in this way is produced.
1. A component of a brake for a vehicle comprising:
a metallic base body which has a surface which is provided with a coating, the coating comprising:
an intermediate layer lying on the base body; and
a covering layer lying on the intermediate layer,
wherein the covering layer is formed from a stainless steel matrix with hard material particles embedded therein,
the hard material particles embedded in the stainless steel matrix of the covering layer have an average grain diameter of 10 μm to 125 μm,
each of the hard material particles has a non-melted core region surrounded at least in sections by a mixing zone having a composition formed from mixing of material of the stainless steel matrix and material of the respective hard material particle, and
each of the hard material particles is materially bonded to the stainless steel matrix by the mixing zone.
2. The component according to claim 1 , wherein the stainless steel matrix of the covering layer consists of a stainless steel with the material number 1.4404 or one of the stainless steels which are standardized in the US American standards AISI/ASTM under the numbers 316-431L.
3. The component according to claim 1 , wherein, a surface hardness of the covering layer is 850-1050 HV10.
4. The component according to claim 3 , wherein a difference between a smallest value Hmin of the surface hardness determined at a free surface of the covering layer and a largest value Hmax of the surface hardness determined at the free surface of the covering layer is at most 100 HV10.
5. A method for manufacturing a component for a brake for a vehicle, comprising:
producing an intermediate layer on a surface of a base body of the component; and
producing, by a method of laser deposition welding, in which a laser beam is moved over a stainless steel powder applied to a free surface of the intermediate layer, a covering layer on the intermediate layer, wherein the covering layer comprises a stainless steel matrix with hard material particles embedded therein,
wherein during production of the covering layer, the laser beam is directed at the stainless steel powder applied to the intermediate layer with a laser intensity of 0.1-2.5 KW/mm 2 ,
a spot, in which the laser beam impinges on the applied stainless steel powder and in which the stainless steel powder is melted to form a melt bath, has a diameter of 2.5-15 mm, and
hard material particles with an average grain diameter of 15 μm to 135 μm are added into the melt bath thus formed.
6. The method according to claim 5 , wherein the hard material particles embedded in the stainless steel matrix of the covering layer have an average grain diameter of at most 105 μm.
7. The method according to claim 6 , wherein the hard material particles embedded in the stainless steel matrix of the covering layer have an average grain diameter of at most 60 μm.
8. The method according to claim 5 , wherein the hard material particles embedded in the stainless steel matrix of the covering layer have an average grain diameter of at least 20 μm.
9. The method according to claim 8 , wherein the hard material particles embedded in the stainless steel matrix of the covering layer have an average grain diameter of at least 45 μm.
10. The method according to claim 5 , wherein the laser intensity of the laser beam used for producing of the covering layer is at most 1.2 KW/mm 2 .
11. The method according to claim 5 , wherein a laser power of the laser beam used for producing of the covering layer is 6-25 KW.
12. The method according to claim 5 , wherein the component is preheated to a preheating temperature of 100-700° C. prior to impingement of the laser beam.
13. The method according to claim 12 , wherein the component as a whole is preheated to the preheating temperature prior to application of the stainless steel powder.
14. The method according to claim 12 , wherein the component is preheated to the preheating temperature in a locally restricted manner in a section in which the stainless steel powder is subsequently melted by the laser beam.
15. The method according to claim 14 , wherein the component is preheated in a manner leading the laser beam.
16. The method according to claim 12 , wherein the preheating is carried out by means of inductive heating.