WEAR-RESISTANT MATERIAL, LOCALLY-REINFORCED LIGHT METAL MATRIX COMPOSITES AND MANUFACTURING METHOD

Abstract

A composition of the wear-resistant material of the present invention includes high-temperature resistant skeleton metal materials, ceramic fiber materials and ceramic particle materials with the mass ratio of (10-60):(1-30):(10-70). The high-temperature resistant skeleton metal materials are foam metal or high-temperature resistant metal fibers. The wear-resistant material is good in wear-resistance, high in tenacity, suitable for occasions with high requirements for wear-resistance and tenacity and capable of being locally attached to the surface of the light metal alloy matrix to improve the wear-resistance and tenacity of the light metal alloy matrix under high temperature conditions. The locally-reinforced light metal matrix composites of the present invention are the light metal alloy matrix locally-reinforced through the wear-resistant material. A manufacturing method of the locally-reinforced light metal matrix composites of the present invention is to metallurgically bond the wear-resistant layer with the light metal alloy matrix is through the squeeze casting technique.

Claims

1. A wear-resistant material, comprising high-temperature resistant skeleton metal materials, ceramic fiber materials and ceramic particle materials with the mass ratio of (10-60):(1-30):(10-70); the high-temperature resistant skeleton metal material are foam metal or high-temperature resistant metal fibers; the high-temperature resistant metal fibers comprise one or more of iron-based alloy fibers, nickel-based alloy fibers, copper-based alloy fibers, stainless steel fibers, steel wool fibers, titanium-based alloy fibers and cobalt-based alloy fibers; the ceramic fiber materials comprise one or more of alumina fibers, alumina silicate fibers, silicon dioxide fibers, zirconium oxide fibers, silicon carbide fibers, graphite fibers and carbon fibers; the ceramic particle materials comprise one or more of flyash particles, superfine slag powder particles, silicon carbide particles, silicon dioxide particles, boron nitride particles, zircon powder particles, brown fused alumina particles, zirconium oxide particles, zirconium silicate particles and chromic oxide particles.

2. The wear-resistant material according to claim 1, wherein the ceramic particle materials are mixed with auxiliary reinforcing particles, the auxiliary reinforcing particles are graphite particles and/or steel slag particles; the steel slag particles are one or more of iron oxide particles, zinc oxide particles, calcium oxide particles, magnesium oxide particles, aluminum oxide particles and titanium oxide particles.

3. The wear-resistant material according to claim 1, wherein the foam metal is foam copper, foam iron, foam nickel or foam iron-nickel.

4. The wear-resistant material according to claim 1, wherein the ceramic fiber materials have the diameter of 5-15 μm and the length of 0.8-2.8 mm, the high-temperature resistant metal fibers have the diameter of 0.01-2 mm, the ceramic particle materials have the granularity of 5-200 μm and the Mohs hardness of 5-9, the foam metal has the porosity of 10-60 ppi.

5. A locally-reinforced light metal matrix composites, comprising a light metal alloy matrix and a wear-resistant layer locally attached to the surface of the light metal alloy matrix; the light metal alloy matrix is an aluminum alloy matrix or a magnesium alloy matrix; a composition of the wear-resistant layer comprises high-temperature resistant skeleton metal materials, ceramic fiber materials, ceramic particle materials, a low-temperature binding agent and a high-temperature binding agent with the mass ratio of (10-60):(1-30):(10-70):(0.5-8):(0.5-10); the high-temperature resistant skeleton metal materials are foam metal or high-temperature resistant metal fibers; the high-temperature resistant metal fibers comprise one or more of iron-based alloy fibers, nickel-based alloy fibers, copper-based alloy fibers, stainless steel fibers, steel wool fibers, titanium-based alloy fibers and cobalt-based alloy fibers; the ceramic fiber materials comprise one or more of alumina fibers, alumina silicate fibers, silicon dioxide fibers, zirconium oxide fibers, silicon carbide fibers, graphite fibers and carbon fibers; the ceramic particle materials comprise one or more of flyash particles, superfine slag powder particles, silicon carbide particles, silicon dioxide particles, boron nitride particles, zircon powder particles, brown fused alumina particles, zirconium oxide particles, zirconium silicate particles and chromic oxide particles; the low-temperature binding agent is a carboxymethylcellulose aqueous solution with the concentration of 3-20%, and the high-temperature binding agent is a silica sol solution with the concentration of 10-60%.

6. The locally-reinforced light metal matrix composites according to claim 5, wherein the ceramic particle materials are mixed with auxiliary reinforcing particles, the auxiliary reinforcing particles are graphite particles and/or steel slag particles; the steel slag particles are one or more of iron oxide particles, zinc oxide particles, calcium oxide particles, magnesium oxide particles, aluminum oxide particles and titanium oxide particles.

7. The locally-reinforced light metal matrix composites according to claim 5, wherein the foam metal is foam copper, foam iron, foam nickel or foam iron-nickel.

8. The locally-reinforced light metal matrix composites according to claim 5, wherein the ceramic fiber materials have the diameter of 5-15 μm and the length of 0.8-2.8 mm, the high-temperature resistant metal fibers have the diameter of 0.01-2 mm, the ceramic particle materials have the granularity of 5-200 μm and the Mohs hardness of 5-9, the foam metal has the porosity of 10-60 ppi.

9. A manufacturing method of a locally-reinforced light metal matrix composites comprising the following steps: by mass fraction, 1-30% of the ceramic fiber materials, 10-70% of the ceramic particle materials, 0.5-8% of the low-temperature binding agent, 0.5-10% of the high-temperature binding agent are added into a proper amount of water to evenly mix to prepare a ceramic slurry; a fixed amount of the ceramic slurry is poured into a preform mold in which a high-temperature resistant skeleton metal is installed in advance, the pressure is increased to 20-30 MPa, and a semi-finished composites preform is manufacturing through dewatering and pressing; afterwards, the semi-finished composites preform is dried at the temperature 60-200° C. for 10-20 h and then sintered at the temperature of 700-1000° C. for 2.5-4 h to obtain a finished composites perform; and finally, the finished composites preform is attached to the light metal alloy matrix which manufacturing in advance by a squeeze casting technique, a wear-resistant layer preform is metallurgically bond with the light metal alloy matrix, and thus the locally-reinforced light metal matrix composites are obtained.

10. The manufacturing method of the locally-reinforced light metal matrix composites according to claim 9, wherein the manufacturing process of the high-temperature resistant skeleton metal is: a foam metal is machined into a sheet matched with the wear-resistant layer in shape and size, and thus the high-temperature resistant skeleton metal is obtained; or high-temperature resistant metal fibers are sorted, processed, woven and evenly spread in a skeleton preform mold and then compacted, and thus the high-temperature resistant skeleton metal is obtained.

11. The manufacturing method of the locally-reinforced light metal matrix composites according to claim 9, wherein the squeeze casting is replaced with environment-friendly sand mold casting, vacuum die casting, centrifugal casting, low pressure casting, differential pressure casting, metal mold casting, investment casting, lost foam casting or vacuum suction casting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a structural diagram of an automotive aluminum alloy brake disc provided with wear-resistant layers in the first embodiment; and

[0024] FIG. 2 is a structural diagram of a truck magnesium alloy brake drum provided with a wear-resistant layer in the second embodiment.

DESCRIPTION OF THE EMBODIMENTS

[0025] A further detailed description of the invention is given with accompanying drawings and embodiments as follows.

[0026] First Embodiment: an automotive aluminum alloy brake disc provided with wear-resistant layers is manufacturing from cast aluminum alloy designated as A356 in America, wherein the size of the automotive aluminum alloy brake disc is Φ288 mm (outer diameter)*44.6 mm (thickness), and the wear-resistant layers are rings with the size Φ288 mm (outer diameter)*184 mm (inner diameter)*3 mm (thickness). The manufacturing method includes the following steps:

[0027] (1) Foam copper with the porosity 10-60 ppm and the thickness 10 mm is machined into a high-temperature resistant skeleton metal with the size Φ288 mm (outer diameter)*184 mm (inner diameter)*10 mm (thickness), and then the high-temperature resistant skeleton metal is placed in a preform mold.

[0028] (2) By mass, 10% of alumina fibers, 5% of alumina silicate fibers and 40% of flyash particles, 8% of silicon carbide particles, 3% of the carboxymethylcellulose aqueous solution (with the concentration about 20%) and 12% of the silica sol solution (with the concentration about 50%) are evenly mixed with a proper amount of water to prepare ceramic slurry, the ceramic slurry is then poured into the preform mold in which the high-temperature resistant skeleton metal is installed in advance, the preform mold is vacuumized to 1*10.sup.−2 Pa and then pressurized to 20-30 MPa, a ring with the size Φ288 mm (outer diameter)*184 mm (inner diameter)*10 mm (thickness) is fanned through dewatering and pressing, and the ring is then dried at the temperature 130° C. for 10 h and sintered at the temperature of 850° C. for 3 h, so that a single preform is obtained.

[0029] (3) Two single preforms are obtained, connected through six supporting ribs made of foam copper and then placed at specific positions in a squeeze casting mold, A356 aluminum alloy liquid is poured into the squeeze casting mold, mold closing and pressurization are conducted to make the aluminum alloy liquid infiltrate into the porous preforms under pressure till the cavity of the squeeze casting mold is filled with the aluminum alloy liquid, and thus an integrated automotive aluminum alloy brake disc casting with the wear-resistant layers on the upper and lower surfaces is manufacturing.

[0030] (4) The integrated automotive aluminum alloy brake disc casting is subjected to T6 heat treatment and then machined, so that the automotive aluminum alloy brake disc provided with the wear-resistant layers in the first embodiment is obtained, and FIG. 1 is the structural diagram of the automotive aluminum alloy brake disc provided with the wear-resistant layers. As is shown in FIG. 1, the automotive aluminum alloy brake disc includes an aluminum alloy brake disc body 1, wherein the two working surfaces of the aluminum alloy brake disc body 1 are each attached with one wear-resistant layer 2, the two wear-resistant layers 2 are connected through the six supporting ribs 3, and the six supporting units 3 are arranged at intervals in the circumferential direction of the two wear-resistant layers 2.

[0031] Second Embodiment: a truck magnesium alloy brake drum provided with a wear-resistant layer is manufacturing from cast magnesium alloy designated as AZ91D in America, wherein the size of the truck magnesium alloy brake drum is Φ480 mm (outer diameter)*227 mm (height), and the size of the wear-resistant layer is Φ420 mm (outer diameter)*180 mm (height)*7 mm (thickness of the cylindrical wall). The manufacturing method includes the following steps:

[0032] (1) By mass, 40% of high-strength steel fibers with the diameter 0.4-1 mm are sorted, woven and spread in a cylindrical preform mold and then compacted, so that a high-temperature resistant skeleton metal is manufacturing and placed at the position close to the inner wall of the preform mold; then 12% of alumina silicate fibers, 41% of silicon carbide particles, 5% of the carboxymethylcellulose aqueous solution (with the concentration about 20%) and 10% of the silica sol solution (with the concentration about 60%) are evenly mixed with a proper amount of water to prepare ceramic slurry, a fixed amount of ceramic slurry is then poured into the preform mold, the preform mold is made to rotate around the central axis, so that the ceramic slurry infiltrates into seams of the fibers under the effect of centrifugal force and part of water is removed, and a cylindrical preform blank with the size Φ420 mm (inner diameter)*180 mm (height) *12 mm (thickness of the cylindrical wall) is obtained.

[0033] (2) The cylindrical preform blank with the size Φ420 mm (outer diameter)*180 mm (height)*12 mm (thickness) is then dried at the temperature 100° C. for 15 h and then sintered at the temperature 800° C. for 3 h, so that a finished preform is obtained.

[0034] (3) The finished preform is placed at a specific position in the squeeze casting mold, AZ91D magnesium alloy liquid is poured into the squeeze casting mold, mold closing and pressurization are conducted to make the magnesium alloy liquid infiltrate into the porous preform under pressure till the cavity of the squeeze casting mold is filled with the magnesium alloy liquid, and thus a truck magnesium alloy brake drum casting with the wear-resistant layer on the inner wall is manufacturing.

[0035] (4) The truck magnesium alloy brake drum casting is subjected to T6 heat treatment and then machined, so that the finished truck magnesium alloy brake drum provided with the wear-resistant layer in the second embodiment is obtained, and FIG. 2 is the structural diagram of the truck magnesium alloy brake drum. As is shown in FIG. 2, the truck magnesium alloy brake drum includes a cylindrical magnesium alloy brake drum body 1, and the inner wall of the magnesium alloy brake drum body 1 is attached with the cylindrical wear-resistant layer 2.