Cutting disk with diamonds in metal sinter matrix

Abstract

The invention relates to a cutting disk, comprising a core disk (12) that is made of a metal material, and cutting segments (14) that are arranged on the circumference of the core disk (12) and each have a metal sinter matrix (18) in which diamonds (20) are embedded. In addition, aluminium oxide particles (22) are embedded in the metal sinter matrix (18) of each of the cutting segments (14). The aluminium oxide particles are shaped such that they have a surface area / volume (S / V) ratio greater than 5.

Description

[0001] Cutting disc with diamonds in metal sintered matrix

[0002] The invention relates to a cutting disc comprising the features of the preamble of patent claim 1.

[0003] Such cutting discs are known in practice and are used, in particular, for cutting building materials in the form of diamond saws. Structurally, the cutting discs each comprise a substantially circular core disc made of metal, in particular steel, around whose circumference cutting segments are arranged. These segments have an arcuate shape following the circumference and each have a sintered metal matrix, which is made, for example, from cobalt, iron, and nickel. Diamonds are embedded in the sintered metal matrix, which imparts the properties that enable the cutting disc to cut or separate materials such as concrete, natural stone, and the like.When cutting highly abrasive materials such as asphalt, concrete, sandstone and the like, increased demands are placed on the cutting segments, as the cutting process results in high bond wear, which can cause the diamonds to fall out of the metal sinter matrix prematurely and thus partly unused, so that the cutting disc no longer meets the requirements.

[0004] The invention is based on the object of creating a cutting disc of the type mentioned in the introduction with improved wear resistance.

[0005] This object is achieved according to the invention by the cutting disc having the features of patent claim 1.

[0006] According to the invention, a cutting disc is proposed that comprises a core disc made of a metallic material and cutting segments arranged on the circumference of the in particular substantially circular core disc, each having a metal sintered matrix in which aluminum oxide particles are embedded. The wear-inhibiting effect of the aluminum oxide particles can be influenced in particular by their geometry. Thus, it is particularly advantageous for the aluminum oxide particles to be shaped such that they have a surface area / volume (A / V) ratio per unit volume that is greater than 5, in particular greater than 5.14. Such an A / V ratio is present for elongated particles, whereas the A / V ratio is smaller than this value for compressed or block-like bodies or cuboids. For example, an elongated cuboid with edge lengths of 6 mm, 0.9 mm, and 0.7 mm has a surface area A of 20.46 mm. 2and a volume of 3.78 mm 3 , resulting in an A / V ratio of 5.41 mm' 1 In contrast, a block-like cuboid with edge lengths of 4 mm, 1 mm and 1.2 mm has an A / V ratio of 4.6 mm' 1 .

[0007] The addition of aluminum oxide particles to the sintered metal matrix forming the bonding system significantly increases the wear resistance of the grinding segments. Aluminum oxide is inexpensively available, which is why the cutting disc designed according to the invention can also be manufactured cost-effectively. Furthermore, the aluminum oxide particles can be fine-grained, creating cutting edges in the cutting insert that contribute to the cutting effect on construction materials such as asphalt.

[0008] The aluminum oxide particles are light and therefore stand out clearly in color from the metal sinter matrix, so that a customer or user can also visually perceive the properties of the cutting disc designed according to the invention.

[0009] The cutting disc according to the invention is particularly suitable for cutting highly abrasive materials such as asphalt, concrete or the like.

[0010] Furthermore, it has been shown that the wear resistance of the cutting segments can be improved if the aluminum oxide particles are each rod-shaped.

[0011] In another specific embodiment of the cutting disc according to the invention, the aluminum particles are provided with depressions on their surfaces, which further increases the surface-to-volume (S / V) ratio. Depending on the application, the proportion of aluminum oxide particles in the sintered metal matrix can vary. In particular, the aluminum oxide particles in the sintered metal matrix each have a proportion of preferably 1 to 30 wt.%, especially 2 to 20 wt.%.

[0012] It is conceivable that the aluminum oxide particles are crystalline. Typically, the aluminum oxide particles are made of sintered corundum, i.e., a ceramic material.

[0013] The aluminum oxide particles can be statically distributed in the sintered metal matrix. However, in a special embodiment of the cutting disc according to the invention, the aluminum oxide particles are arranged in a set pattern within the sintered metal matrix, which can have a positive effect on wear resistance.

[0014] The cutting segments are manufactured primarily by sintering a powder or granulate.

[0015] The metal sinter matrix of the cutting segments of the cutting disc according to the invention can comprise various metals such as cobalt, iron, tin, and nickel. The metal sinter matrix preferably has a proportion of iron, tin, nickel, and / or cobalt in the range of 8 to 75 wt.%, which is added in the form of powder or granules during the production of the cutting segments.

[0016] Furthermore, the metal sinter matrix can contain copper and / or a copper-based alloy (bronze), preferably in a proportion of 5 to 40 wt.%. These components can also be added in powder or granular form during the production of the cutting segments, i.e., before sintering. The copper added in this way can react with the aluminum oxide particles and, particularly through spinel formation, lead to good integration of the aluminum oxide particles.

[0017] In addition, the metal sinter matrix can comprise hard materials and / or a hard alloy, in a proportion of 0.1 to 40 wt.%. Hard alloys include, for example, hard materials sold under the brand names Colmonoy or Deloro, which are metallic or intermetallic (self-fluxing) hard alloys based on nickel, silicon, and boron.

[0018] Furthermore, it is advantageous if the metal sinter matrix contains iron phosphide. This preferably has a proportion of 0.5 to 50 wt.%. The phosphorus in the iron phosphide reduces the aluminum oxide on the surface of the aluminum oxide particles to metallic aluminum. This can be easily sintered with the metal powders or metal granules during the production of the cutting segments and increases the hardness of the metal sinter matrix.

[0019] The resulting phosphorus-iron bond, especially with the addition of copper and / or tin and / or bronze during sintering, ensures good wetting of all particles, especially the aluminum oxide particles. Under the influence of high sintering temperatures and high sintering pressure, the phosphorus can react with aluminum oxide, causing it to deoxidize. This results in a thin aluminum coating on the aluminum oxide particles. This ensures good bonding of the aluminum particles in the metal sinter matrix.

[0020] Further advantages and advantageous embodiments of the subject matter of the invention can be found in the description, the drawings and the patent claims.

[0021] An embodiment of a cutting disc according to the invention is shown schematically in simplified form in the drawing and is explained in more detail in the following description.

[0022] The only figure in the drawing shows a schematic partial view of a cutting disc designed as a diamond saw according to the invention.

[0023] The drawing shows a cutting disc 10 which is particularly suitable for cutting or separating materials such as asphalt. The cutting disc 10 comprises a substantially circular core disc 12 made of steel and having a central receptacle 13 for a drive shaft of a suitable machine tool. Around its circumference, the core disc 12 carries a plurality of cutting segments 14 arranged one behind the other, each separated from one another by a slot or notch 16 which also extends into the core disc 12. The cutting segments 14, which represent the effective separating means of the cutting disc 10 and are connected to the core disc in particular by a laser welding process using a CO2 laser or fiber laser, or alternatively by a brazing process or an adhesive process, in this case each have an arcuate shape that follows the circumference of the core disc 12.

[0024] The cutting segments 14 each have a metal sintered matrix 18 made of 10 to 75 wt.% iron powder, 5 to 40 wt.% copper or copper-based alloy powder, 0 to 40 wt.% hard materials, and 0.5 to 15 wt.% iron phosphide powder. Furthermore, the cutting segments 14 each comprise rod-shaped aluminum oxide particles 22 with a proportion of 1 to 30 wt.%, as well as diamonds 20 as cutting-active materials. The aluminum oxide particles 22 and the diamonds 20 are embedded in the metal sintered matrix 18.

[0025] The aluminum oxide particles 22, which are made of sintered corundum, each have a rod-shaped geometry and a surface / volume ratio of at least 5.14 per unit length.

[0026] In a base region adjacent to the core disk 12, the cutting segments 14 have, in particular, a composition that differs from that of the actual cutting matrix and, due to the welding process used for connection, contains more cobalt and / or iron and / or nickel and less copper and / or bronze components.

[0027] 10 cutting disc

[0028] 12 core disc

[0029] 13 Holder 14 Cutting segment

[0030] 16 incision

[0031] 18 metal sinter matrix 0 diamonds 2 aluminum oxide particles

Claims

A cutting disc comprising a core disc (12) made of a metallic material and cutting segments (14) arranged on the circumference of the core disc (12) and each having a sintered metal matrix (18) into which diamonds (20) are embedded, wherein aluminum oxide particles (22) are embedded in the sintered metal matrix (18) of the cutting segments (14), characterized in that the aluminum oxide particles (22) are shaped such that they each have a surface / volume (A / V) ratio greater than 5. A cutting disc according to claim 1, characterized in that the aluminum oxide particles (22) are each rod-shaped. A cutting disc according to claim 1 or 2, characterized in that the aluminum oxide particles (22) have a proportion of 1 to 30 wt.% in the sintered metal matrix (18).Cutting disc according to one of claims 1 to 3, characterized in that the aluminum oxide particles (22) are formed from sintered corundum. Cutting disc according to one of claims 1 to 4, characterized in that the sintered metal matrix (18) comprises 8 to 75 wt.% iron, nickel, tin, and / or cobalt. Cutting disc according to one of claims 1 to 5, characterized in that the sintered metal matrix (18) comprises 5 to 40 wt.% copper and / or a copper-based alloy. Cutting disc according to one of claims 1 to 6, characterized in that the sintered metal matrix (18) comprises 0.1 to 40 wt.% hard materials and / or a hard material alloy. Cutting disc according to one of claims 1 to 7, characterized in that the sintered metal matrix (18) comprises 0.5 to 15 wt.% iron phosphide. Cutting disc according to one of claims 1 to 8, characterized in that the aluminum oxide particles (22) are arranged regularly and / or in patterns in the sintered metal matrix (18).

Images