JP2001310263A - Super-abrasive grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize improvement of sharpness and elongation of a service life of a tool by closely examining bond material for bonding super-abrasives in a super-abrasive tool for machining or grinding. SOLUTION: A cutting edge 2 is formed by sintering the super-abrasives on a base plate 1 made of an Al alloy, steel, or the like with using Al or its alloy as a parent body of holding bond material for the super-abrasives (diamond, boron nitride, boron carbide, boron carbonitride, and the like) with adding metallic element including Cu, Mg, Zn, Ti, and iron family elements (Fe, Ni, Co). For one example, Cu is added to Al-Al2O3 dispersion-strengthened material (SAP), and abrasive grain diamond is sintered at 500-600 deg.C. Since sintering temperature is low, thermal deterioration (oxidation, allotropic modification) is fully prevented, and improvement of sharpness and elongation of the service life of tool are realized as the grinding wheel for machining or grinding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding wheel using superabrasive grains (diamond, boron nitride, boron carbide, carbonation boron nitride, etc.), and more particularly to a grinding wheel suitable for a grinding wheel for cutting or grinding. The present invention relates to a superabrasive tool using an abrasive holding material (bond).

[0002]

2. Description of the Related Art Generally, there are three types of bond materials for holding abrasive grains of a tool using superabrasive grains: resin bond, vitrified bond and metal bond. The abrasive holding power of these bonds depends on the longitudinal elastic modulus (Young's modulus) of the bond material.

[0003] The following shows the Young's modulus of each bond material. Resin bond = 2.8 to 3.5 x 10²kg / mm²  Vitrified bond = 5.0-8.0 × 10²kg / m
m²  Metal bond (20% Sn-Cu Bronz) ≒ 9.
7 × 10³kg / mm²

As described above, the holding power of superabrasive grains is
The difference in strength is large. Alminyum and its alloys
Is approximately 6.3 to 13.0 × 10³kg / m
m² The range is wide depending on the degree and composition and the structure to be precipitated.
It can cover the bond material.

[0005] The holding power of superabrasive grains is a stress in an elastic range and can be calculated by Hooke's law. Also,
The interference is calculated by the following formula. [Coefficient of thermal expansion of bond-Coefficient of thermal expansion of superabrasive particles] × [Recrystallization temperature of material−Room temperature] = σ (embracing force) × 1 (abrasive particle size) /
E (Young's modulus)

[0006]

The cutting or grinding with superabrasive grains is performed, for example, by holding superabrasive grains that can withstand cutting (grinding) shafts corresponding to the cutting (grinding) conditions of the object to be cut (grinding). Having power is a prerequisite.

[0007] In the case of a bond having a small holding force, such as a resin bond, in order to reduce the load of a unit superabrasive, a highly concentrated, fine superabrasive is used. Used for finish grinding, heavy load of unit super abrasive,
In the case of low speed and high load, a metal bond having a large holding stress is used.

Bronz often used as a metal bond
The bond has a large load on the unit superabrasive grains.
The contact stress of the superabrasive cutting edge becomes excessive, the cutting edge is thermally worn, the contact area of the (cutting object-cutting edge) increases, the stress decreases, and the sharpness is lost. Therefore, it is necessary to repeat the "finding" polishing of the grinding wheel.

An object of the present invention is to solve the above problems. In a superabrasive grinding wheel, a bond material is selected and sintered in a temperature range in which the oxidation reaction of the superabrasive is inactive. By doing so, the sharpness of the superabrasive tool is improved and the life of the tool is extended.

[0010]

In order to solve the above-mentioned problems, the present invention relates to a method of using diamond as a super-abrasive, in which the oxidation reaction of the super-abrasive diamond has an inactive diffusion reaction with a metal element. As a result of various attempts at devising a superabrasive diamond and a holding metal sintered body bond in the temperature range, Al, A
_l-Al 2 _{O 3} (called SAP), or, for enhanced maternal these metals, done Cu, Zn, Mg, and strengthening of the precipitation phase by the addition of Ti or the like, the dispersion strengthening of the iron group metal element , Developed a bond.

One example of the present invention is a dispersion strengthened alloy SAP (Sintered Aluminum) of Al-Al ₂ O _3.
um Powder Product) as a base material, to improve the holding power of superabrasive grains, and to add a metal element having a large diffusion coefficient with Al at a sintering temperature of 500 to 600 ° C to increase the strength of the sintered body and the bonding Young It is a super-abrasive tool with good cutting and grinding properties that improves the holding power of super-abrasive grains by increasing the rate and, in addition, completely prevents thermal deterioration of the super-abrasive grains.

Further, in order to enhance the holding power of super-abrasive grains in a sintered body mainly composed of SAP of a dispersion strengthened alloy of Al-Al ₂ O ₃ (Al ₂ O ₃ = 5 to 20 wt%), the bond resistance is increased. In order to improve abrasion, Cu: 0 to 40 wt%, Zn:
1 to 50 wt%, Mg: 15 to 30 wt%, Ti: 0 to 0
In some cases, 5 wt% of a single element or a plurality of elements may be added.

Further, in order to promote dispersion strengthening, an iron group element is added in an amount of 10 to 30 vol%, the distance between (iron group powder-iron group powder) is set to about 0.02 mm, and the brazing strength is ma.
It is also possible to improve bond strength and abrasion resistance by setting x.

(Al-Fe) is Fe ₂ Al, FeA
1, intermetallic compounds such as FeAl ₂ , Fe ₂ Al ₅ , FeAl ₃ become very brittle when produced, but the sintering temperature of the aluminum alloy is 500 to 600 ° C.
Because of the low temperature, and because of solid phase sintering or liquid phase interposition sintering, the reaction rate is slow and it does not become an extremely brittle material,
It improves bond strength, abrasion resistance, and holding power of superabrasive grains.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
The case where superabrasive grains are sintered will be described as an example. FIG.
2 are side views of the superabrasive grinding wheel of the present invention, wherein FIG. 1 is for cutting and FIG. 2 is for grinding.

As shown in these figures, the super-abrasive grinding wheel of the present invention comprises diamond, boron nitride, boron carbide, nitrogen carbide on the circumferential end of a metal substrate 1 made of steel or aluminum alloy or the like. Of carbonized borax, etc., any super abrasive,
The cutting blade 2 is formed by sintering the bonding material.

The bond material holding the superabrasive grains includes A
l-Al ₂ O ₃ dispersion strengthened alloy (commonly known as SAP: Sint
ered Aluminum Powder Pro
duct) as a matrix, and a sintering temperature of 500
A metal element having a high diffusion coefficient with Al at up to 600 ° C is added to improve the strength of the sintered body and lower the sintering temperature, thereby completely preventing the thermal deterioration of the superabrasive grains. Thus, a long-lasting tool having good sharpness was obtained.

Al—Al ₂ O ₃ or Al—A
The metal element to be added to the dispersion strengthened alloys of _{l 2 O 3, Cu: 0~40wt} %, Mg: 15~30wt%,
It is preferable to mix a single element or a plurality of elements among Zn: 10 to 50 wt%, Ti: 0 to 5 wt%, and iron group elements (Fe, Ni, Co): 10 to 30 volm%. Bonds made of a sintered alloy to which these metal elements are added have excellent self-action and can maintain a constant sharpness in order to promote metabolism of the cutting edge.

Here, B produced under the same superabrasive grain conditions,
Test examples using a ronz-based metal bond grinding wheel and an aluminum alloy-based grinding wheel will be described. The test is 60mmφ
The test was performed with a 4 mmW grinding wheel at a rotation speed of 3600 rpm, a feed speed of 50 mm / min, and a depth of cut of 4.0 mm. Soda glass was used as the object to be cut.

The surface roughness after cutting is (Bronz bond)
/ (Aluminum bond) ≒ 2 × μ / xμ, and the roughness is fine. The reason is that in the case of the aluminum bond grindstone, the superabrasive grains hardly lost or fell off (almost 0%).

High-temperature sintering causes heat loss of the superabrasive grains,
It impairs the sharpness of the whetstone and, in addition, deteriorates the holding power of the abrasive grains, causing the cutting edge to be chipped and dropped. Diamond is generally 60
At a temperature of 0 ° C. or less, it is chemically stable and does not deteriorate. Since the sintering of the Al-based bond is performed within the range below this temperature, there is no change in the quality and surface condition of the diamond and the cutting (grinding) property is not impaired. It is possible to ask.

As described above, according to the present invention, the super-abrasive
When using diamond as the diamond abrasive
Is oxygen (0₂) In the state of coexistence,
Even if given, C (diamond) + 0₂= C
O₂, C (diamond) + CO ₂= 2CO, reaction
Due to inertness, diamond is oxidized (combusted)
There is no elementary transformation and the surface condition of the rough stone is maintained, and the sharpness is good
Keep liking.

In addition, between the diamond (super-abrasive) and aluminum or its alloy (bond material), the sintering temperature range of aluminum or its alloy (500 to 6).
(00 ° C.), there is no wear of the cutting blade due to diffusion, and the diamond wheel has excellent cutting (grinding) properties.

[0024]

As described above, according to the present invention, in a grinding wheel for cutting or grinding, sintering of super-abrasive grains using aluminum or an aluminum alloy bond makes it possible to cut or grind the grinding wheel. However, it is significantly improved as compared with the conventional bond, and does not allow other follow-up in long life, good sharpness, and the like.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Substrate 2 Super abrasive grain cutting blade

Claims (2)

[Claims] 1. A super-abrasive grinding wheel characterized in that super-abrasive grains are held by Alminyum or an alloy bond thereof. 2. The method according to claim 1, wherein the bond is Al—Al ₂ O ₃
In addition, Cu: 0 to 40 wt%, Mg: 15 to 30 wt%,
Zn: 10 to 50% by weight, Ti: 0 to 5% by weight, iron group element (Fe, Ni, Co): 10 to 30% by volume. The super-abrasive grinding wheel according to claim 1, wherein the super-abrasive wheel is sintered together.