Lightweight magnesium-based composite brake rotor

Patent metadata

Field	Value
Publication number	US-2025257773-A1
Application number	US-202418439802-A
Country	US
Kind code	A1
Filing date	Feb 13, 2024
Priority date	Feb 13, 2024
Publication date	Aug 14, 2025
Grant date	—

Abstract

A brake rotor for a motor vehicle having a composite structure may include an annular body defining opposite friction surfaces of the brake rotor. The annular body may include a core made of a lightweight, magnesium-based alloy; a thermal barrier layer made of a thermally insulating material disposed on the core; and a wear-resistant layer made of an Al—Fe—Si—Zr alloy of aluminum (Al)+iron (Fe)+silicon (Si)+zirconium (Zr) that is disposed on the core over the thermal barrier layer. The wear-resistant layer may define a first one of the opposite friction surfaces of the annular body.

First claim

What is claimed is:

1 . A brake rotor for a motor vehicle, the brake rotor comprising:
an annular body defining a first friction surface, the annular body comprising:
a core comprising a magnesium-based alloy and including at least one annular disc having an annular surface;
a thermal barrier layer comprising a thermally insulating material disposed on the annular surface of the core; and
a wear-resistant Al—Fe—Si—Zr alloy layer comprising aluminum (Al)+iron (Fe)+silicon (Si)+zirconium (Zr) disposed on the annular surface of the core over the thermal barrier layer; and
wherein the wear-resistant layer defines the first friction surface of the annular body.

2 . The brake rotor of claim 1 , wherein the magnesium-based alloy comprises, by mass, about 93% magnesium (Mg), about 6% aluminum (Al), and about 1% zinc (Zn).

3 . The brake rotor of claim 1 , wherein the magnesium-based alloy comprises about 3.8-5.0 wt. % aluminum, about 0.8-1.5 wt. % zinc, about 0.3-0.7 wt. % manganese, and balance magnesium.

4 . The brake rotor of claim 1 , wherein the magnesium-based alloy comprises a composite material comprising Mg—Al—Zn alloy and Boron Nitride (BN) and/or Boron Carbide (B 2 C).

5 . The brake rotor of claim 1 , further comprising an adhesion-strengthening interlayer disposed in-between the core and the thermal barrier layer comprising a metal or metal alloy selected from Ti (titanium), Cr (chromium), Mo (molybdenum), W (tungsten), Nb (niobium), or Ta (tantalum), or combinations thereof.

6 . The brake rotor of claim 1 , wherein the core has
a density between about 1.7 g/cm 3 to about 1.9 g/cm 3 ; a thermal conductivity between about 90 W/m-K to about 100 W/m-K; a tensile strength between about 260 MPa to about 280 MPa; and a thickness of greater than or equal to about 9 mm to less than or equal to about 36 mm.

7 . The brake rotor of claim 1 , wherein the thermally insulating material comprises a high entropy alloy, a high entropy ceramic, or a combination thereof.

8 . The brake rotor of claim 1 , wherein the thermally insulating material has a thermal conductivity of greater than or equal to about 0.4 W/m-K to less than or equal to 2 W/m-K.

9 . The brake rotor of claim 1 , wherein the Al—Fe—Si—Zr alloy comprises Al 50 Fe 42 Si 6 Zr 2 .

10 . The brake rotor of claim 1 , wherein the Al—Fe—Si—Zr alloy comprises a grain refiner in an amount, by mass, greater than or equal to about 0.05% to less than or equal to about 1% of the Al—Fe—Si—Zr alloy, and wherein the grain refiner comprises at least one of chromium (III) boride and tantalum boride.

11 . The brake rotor of claim 1 , wherein the thermal barrier layer has a thickness of greater than or equal to about 0.05 mm to less than or equal to about 4 mm.

12 . The brake rotor of claim 1 , wherein the wear-resistant layer has a thickness of greater than or equal to about 1 mm to less than or equal to about 4 mm.

13 . The brake rotor of claim 1 , wherein the thermal barrier layer is perforated and includes a plurality of through-holes extending in an axial direction therethrough.

14 . The brake rotor of claim 13 , wherein the wear-resistant layer includes a plurality of anchors that extend from an outer surface of the thermal barrier layer into the plurality of through-holes toward the core.

15 . The brake rotor of claim 14 , wherein the plurality of anchors extends from the outer surface of the thermal barrier layer into the plurality of through-holes to the annular surface of the core, and wherein the wear-resistant Al—Fe—Si—Zr alloy layer is metallurgically bonded to the magnesium-based alloy of the core via the plurality of anchors.

16 . The brake rotor of claim 1 , wherein the core comprises a pair of first and second annular discs spaced apart from each other in an axial direction by a plurality of ribs.

17 . A brake rotor for a motor vehicle comprising:
an annular body defining opposing first and second friction surfaces, the annular body comprising:
a core comprising a magnesium-based alloy and including a pair of first and second annular discs spaced apart from each other in an axial direction by a plurality of ribs, each of the first and second annular discs having an annular surface;
first and second thermal barrier layers comprising a thermally insulating material and respectively disposed on the annular surfaces of the first and second annular discs of the core; and
first and second wear-resistant layers comprising an Al—Fe—Si—Zr alloy comprising aluminum (Al)+iron (Fe)+silicon (Si)+zirconium (Zr), and respectively disposed on the annular surfaces of the first and second annular discs over the first and second thermal barrier layers; and
wherein the first and second wear-resistant layers respectively define the opposing first and second friction surfaces of the annular body.

18 . A method of manufacturing a brake rotor for a motor vehicle, the method comprising:
casting a magnesium-based alloy into a shape of a rotor core including at least one annular disc having an annular surface; depositing a thermally insulating material directly on the annular surface of the rotor core to form a thermal barrier layer; and depositing an wear-resistant Al—Fe—Si—Zr alloy layer comprising aluminum (Al)+iron (Fe)+silicon (Si)+zirconium (Zr) on the annular surface of the rotor core over the thermal barrier layer to form a wear-resistant layer.

19 . The method of claim 18 , wherein the thermally insulating material and the wear-resistant Al—Fe—Si—Zr alloy layer are deposited on the annular surface of the rotor core using a directed energy deposition process.

20 . The method of claim 18 , wherein the thermally insulating material is deposited on the annular surface of the rotor core such that the thermal barrier layer is perforated and includes a plurality of through-holes extending in an axial direction therethrough.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kukreja Ratandeep S
• Liu Zhongyi
• Lee Heewook

Classifications

• F16D2200/003

  Light metals, e.g. aluminium · CPC title

• F16D65/127

  characterised by properties of the disc surface; Discs lined with friction material · CPC title

• F16D65/126

  the material being of low mechanical strength, e.g. carbon, beryllium; Torque transmitting members therefor · CPC title

• F16D65/125 Primary

  characterised by the material used for the disc body · CPC title

• B23K26/34

  Laser welding for purposes other than joining · CPC title