JPS62176769A - Grinding stone - Google Patents

Abstract

PURPOSE:To suppress abrasion and secure a long service life by obtaining the abrasive grains from the unit type sintered particles containing a plurality of superhard minute particles and carrying out the sintering formation by the bonding agent such as resinoid bond, thus increasing the unevenness on the surface of the abrasive grain and increasing the abrasive grain holding force and constituting the cutting edge from the edge lines of the superhard minute particles. CONSTITUTION:An abrasive grain 1 is made of the unit type sintered body particle containing a plurality of superhard minute particles which are obtained by pulverizing the sintered body of the superhard minute particles 2 made of diamond, wurtzite type boron nitride, cubic system boron nitride, etc., having the ceramics such as TiC, TiN, and Al2O3 as bonding agent 3. The sintering formation with the bonding agent 4 such as resinoid bond and vitrified bond is carried out to obtain a grinding stone. Since the abrasive grain 1 is constituted in unit form from a plurality of superhard minute particles 2, the shape of the surface of the abrasive grain 1 is rich in unevenness, and the abrasive grain holding force is improved. Further, a metal covering layer does not exist, and the cutting edge of the abrasive grain 1 is constituted of the edge line parts of the superhard minute particle 2 itself, and the abrasion of the cutting edge is suppressed, and the long service life can be secured.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an improvement in a grinding wheel formed by sintering diamond or cubic boron nitride particles as abrasive grains with a binder such as resinoid bond or vitrified bond.

[Prior art]

DIA) or cubic boron nitride (hereinafter referred to as Cl5N) single crystal or polycrystalline particles are used as abrasive grains (hereinafter referred to as Cl5N).
Size 60-600mesh=220-30μ) is known to be formed by electrodeposition, or by sintering with a binder such as resinoid bond, vitrified bond, metal bond, etc. By the way, in order to improve the grinding performance of these whetstones, it is important to sufficiently retain the abrasive grains without causing them to fall off or break, and in order to increase the retention power, the above-mentioned IA or C is usually used.
The surfaces of the 15N particles are coated with a metal such as Ni or Cu to form abrasive grains. FIG. 2 is a diagram showing the coated state of the abrasive grains 1. As for the abrasive grains 1, the surface shape of the coating layer 10 is considerably more uneven than the surface shape of the particles 11. Therefore, the abrasive grains having the coating layer 10! can obtain a good interlocking state with the binder and increase its holding power.

[Problem to be solved by invention]

Sea Ama μ, ho small trr hand heavy sill right six nails 1'f
lli 7: is used as a high-efficiency grindstone for grinding or cutting high-hardness materials and difficult-to-cut materials, but it is still lacking in terms of abrasive grain retention and wear resistance of the cutting edge of the abrasive grains. It's not completely satisfying. In reality, when grinding with a grinding wheel using metal-coated abrasive grains, a considerable amount of the abrasive grains fall off, and if you look at the state of the abrasive grains, for example, in a micrograph,
In some cases, the entire metal coating has fallen off, while in others, only the DIA or CBN particles have fallen off, leaving the coating layer in the binder matrix. In this way, considering the case where only particles fall from inside the metal coating, the coating layer is soft compared to ultra-hard particles, and when this coating layer wears away and the particle surface is exposed, the particle surface originally Since the surface of the coating layer has less undulations than the surface of the coating layer, it seems that the coating layer's holding force against the particles is such that only the particles easily fall off. Therefore, to put it bluntly, it is considered that in terms of the problems of wear of the coating layer (dulling of the edge of the cutting edge) and falling off of particles, it is better not to have the coating layer. Therefore, an object of the present invention is to provide a grinding wheel in which the coating layer of the abrasive grains is removed, the retention force for the abrasive grains is increased, and the blunting of the cutting edge is prevented to improve the grinding performance. be.

[Means for solving problems]

Grinding wheel C according to the present invention, T I C, T i N,
A plurality of the above-mentioned materials obtained by crushing a sintered body of ultrahard fine particles such as diamond, wurtzite boron nitride (hereinafter referred to as WBN), and cubic boron nitride using a ceramic such as A I 203 as a binder. Unit-shaped sintered particles containing ultra-hard fine particles are used as abrasive grains, and are sintered with a binder such as resinoid pound or vitrified bond.

[Action/effect]

According to the grinding wheel according to the present invention, since the abrasive grains are formed into a unit by a plurality of ultrahard fine particles, the surface shape of the abrasive grains is rich in undulations, and the abrasive grain retention power is increased. In addition, since there is no metal coating layer and the cutting edge of the abrasive grain is formed by the ridge of the superhard fine particles themselves, there is almost no wear on the cutting edge and a long life can be achieved. Furthermore, this abrasive grain is DIA
, WBN or CBN particles as T i C, T i
Because it is obtained by crushing a sintered body that has been sintered with a binder such as N, Alt 03, etc., it has many sharp cutting edges, and each ultrahard fine particle of the unit-shaped abrasive grains cannot be individually cleaved or crushed. Even if abrasion occurs, a new sharp cutting edge is created at that location, resulting in a significant improvement in grinding performance.

【Example】

A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the structure of a grinding wheel according to the present invention. As shown in the figure, the abrasive grains 1 are made up of a plurality of ultra-hard fine particles 2.
or are combined into a unit. 3 is a binding material, which is a ceramic such as TiC, TiN, Alt03, etc. That is, the abrasive grains 1 can be obtained by pulverizing a sintered body formed by sintering particles of DIA, WBN, CBN, etc. with a binder such as TiC, TiN, AI, O*, etc. The average particle size of the abrasive grains obtained by pulverization is 0.03 to 3.
mm, and has a granular shape. The grinding wheel of the present invention has this 6-sho t1-te 11. +i: NO NO NO K NO NO K MESH K 1 BLIND 7- NO W-+Z- It is newly sintered and formed using a binder 4 such as a wire or metal bond.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the structure of the grinding wheel according to the present invention, and FIG. 2 is a diagram showing the metal coating state of conventional abrasive grains. l... Abrasive grains, 2... Super hard fine particles, 3... Binding material,
4...Binder,

Claims (1)

[Claims] (1), a sintered body of ultra-hard particles (2) of diamond, wurtzite boron nitride, cubic boron nitride, etc. is crushed using a ceramic such as TiC, TiN, Al_2O_3 as a binder (3). A plurality of the ultrahard fine particles (2
1. A grinding wheel characterized in that the abrasive grains (1) are unit-shaped sintered particles containing the following: ), and the abrasive grains (1) are sintered with a binder (4) such as resinoid bond or vitrified bond.