JPH03213272A - Vitrified super-abrasive grinding wheel - Google Patents

Abstract

PURPOSE:To reduce the extent of grinding force so remarkably and make possible highly efficient grinding, by turning aggregate into vitreous particles having a higher softening point than a vitrified bond. CONSTITUTION:Super-abrasive grains 1 of cubic system boron nitride, diamond or the like and aggregate 2 are bound by a vitrified bond 3, producing a vitrified super-abrasive grinding wheel. At this time, the aggregate 2 is turned into vitreous particles having higher softening point than this vitrified binder 3 in terms of constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vitrified superabrasive grindstone in which superabrasive grains and aggregate are bonded together using a vitrified bonding agent.

[Prior Art] Conventionally, when manufacturing a vitrified superabrasive grindstone using superabrasive grains such as cubic boron nitride or diamond as abrasive grains, the abrasive grain concentration is medium to low odor. In order to prevent shrinkage during sintering, aggregate is mixed into the grindstone. Further, as the aggregate, aluminum nine-silicon carbide or the like is generally used.

[Problems to be Solved by the Invention] However, when aggregates such as aluminum non-silicon carbide are used in superabrasive grindstones, there is a problem in that the grinding resistance increases, making it impossible to perform good grinding work.

In other words, aggregates such as alumina and silicon carbide are hard with a new Mohs hardness of 12 to 13 and can act as secondary abrasive grains, but superabrasives such as cubic boron nitride and diamond (new Mohs hardness: 14) -15) If used at the same time, the surface will wear flat due to friction with the material to be ground, the grinding resistance will increase, the sharpness will deteriorate, and high-efficiency grinding will become impossible.

When the sharpness of a whetstone deteriorates in this way, dressing (so-called sharpening) is usually used to restore the sharpness, but since dressing wears down the whetstone, usable abrasive grains and even the binder may fall off. This causes problems such as deterioration of the durability of the whetstone and the cost of dressing.

SUMMARY OF THE INVENTION Therefore, the present invention has been made to provide a vitrified superabrasive grindstone which can lower the grinding resistance due to aggregate and perform highly efficient grinding without dressing.

[Means for Solving the Problems] That is, the present invention, which has been made to achieve the above object, provides a vitrified material made by bonding superabrasive grains such as cubic boron nitride, diamond, etc. and aggregate with a vitrified bonding agent. The gist of the present invention is a vitrified superabrasive grindstone, characterized in that the aggregate is glassy particles having a higher softening point than the vitrified binder.

[Operation and Effects of the Invention] As described above, in the vitrified superabrasive grindstone of the present invention, glass particles are used as the aggregate.

The hardness of glassy particles is relatively low at 6 to 7 on the new Mohs hardness scale, and since glass is a brittle material, it is easily worn when it comes into contact with the workpiece during grinding, and the phenomenon that the workpiece adheres to the aggregate occurs. It becomes difficult to wake up. In addition, the vitreous particles are compatible with the vitrified binder, so that the aggregate is strongly bonded to the vitrified binder by sintering.

Therefore, according to the vitrified superabrasive grindstone of the present invention, the grinding resistance can be significantly lowered compared to the conventional grinding wheel, and high efficiency grinding is possible.

This is a whetstone suitable for grinding abrasive materials that do not like grinding.

In addition, since grinding resistance is less likely to increase and sharpness deteriorates, there is no need for frequent dressing as in the past, making it possible to provide a super-abrasive grinding wheel that is easy to use and expanding the fields of use of super-abrasive grinding wheels. .

Here, the softening point of the glass particles used for the aggregate needs to be higher than the softening point of the vitrified binder so that the aggregate does not deform during sintering, and the softening point of the glass particles used for the aggregate must be 100°C higher than the softening point of the vitrified binder. The glass particle size is preferably 1° or more, and various glasses such as borosilicate glass, lithium-alumina-silica crystal glass, and quartz glass can be used as the glassy particles. Alumina-silica crystal glass and quartz glass are more preferred because they have a high softening point.

[Example] Next, as an example of the present invention, the shape as shown in FIG.
, 10.50.8 [mm], and under the following conditions, and with the type of aggregate (vitreous particles) changed as shown in Table 1, superabrasive grinding wheels (Samples 1 to 4) were prepared. size,
Under the same conditions, a conventional superabrasive grindstone (Sample 5) using alumina as aggregate was produced, and a surface grinding test was conducted on each superabrasive grindstone (Samples 1 to 5). As shown in FIG. 1(b), the superabrasive grindstone produced in this way has superabrasive grains 1 and aggregates 2 bonded together by a binder 3. It becomes a medium concentration superabrasive grinding stone with 4 pores.

(Component) Cubic boron nitride #140/170 25 volume parts Aggregate #140/170 2
5 n vitrified binder (softening point 620°, organic binder (sintering temperature) 9006C, 5 hour table) C) 0 The grinding conditions are as follows.

Grinding wheel peripheral speed 2000m/min Material to be ground 5KDII HRC62 (dimensions 15
0mm x 20mm) Table speed 15m/min Lateral feed 3mm/pass Depth of cut lOμ Grinding fluid JISW2 As shown in Table 1, the results of the above surface grinding test show that sample 5, whose aggregate is alumina, has a large grinding resistance and a low grinding ratio. On the other hand, it can be seen that in Samples 1 to 4 in which the aggregate was made of glass particles, the higher the softening point, the lower the grinding resistance. It is also clear that the grinding ratio is greater than that of sample 5 in all samples (samples 1 to 4), regardless of the softening point. It can be seen that the grinding resistance can be reduced and the grinding ratio can be improved compared to the super abrasive grindstone.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the shape and internal structure of a superabrasive grindstone of an example. ]... Super abrasive grains 2... Aggregate 3... Binder 4... Pores

Claims (1)

[Claims] A vitrified superabrasive grinding wheel in which superabrasive grains such as cubic boron nitride or diamond are bonded to aggregate using a vitrified bonding agent, wherein the aggregate has a higher softening property than the vitrified bonding agent. A vitrified superabrasive grinding wheel characterized by glassy particles having dots.