JPS6094205A - Hard ceramics cutting method - Google Patents

Abstract

PURPOSE:To cut hard ceramics efficiently by cooling only a sintered diamond tool with a heat sink and cutting hard ceramics having Vickers hardness of above 600 with the sintered diamond tool in dry process. CONSTITUTION:In case of cutting hard ceramics with a sintered diamond tool, only the diamond cutring edge of the above tool is cooled by a heat sink, and hard ceramics having Vickers hardness of above 600 is cut by the above tool in dry process. For example, sintered diamond 8 mainly composed of diamond having the average partial size 20-30mum is machined to form a chip of 13phi, and the chip is mounted on a tool holder 9. After that, Si3N4 having Vickers hardness of 1,300 is cut by a heat sink 10 of Cu. Thus, hard ceramics can be cut efficiently as compared with the case where sintered diamond 8 is cut without cooling.

Description

[Detailed description of the invention] (a) Background of the technology
As a result, high-strength ceramics have been quantified and are being used for important mechanical parts, etc. These hard ceramics have poor heat resistance, and are The current situation is that grinding with a diamond whetstone is only possible. Grinding with a diamond whetstone is expensive, and it is difficult to process parts with compatible shapes.
However, the range of use of these ceramic mechanical parts is often limited.

(B) Disclosure of the Invention In order to eliminate this obstacle, the present inventors have conducted extensive research on cutting hard ceramics using a sintered diamond tool, which has high strength and excellent wear resistance.

As a result, it was found that cutting could be performed efficiently by cooling only the sintered diamond without cooling the hard ceramic. Usually, hard ceramic is produced using sintering die A/send tool.
In particular, 5SBN4 sintered bodies and SiC sintered bodies are
In this case, as shown in FIG. 1, wear 2 at the tool boundary develops significantly in a short cutting time, and the cutting resistance increases significantly, leading to chipping and failure. The reason for this lIj can be considered as follows. When cutting ceramics, a sintered diamond tool generates microcracks near the surface, which propagate and remove the ceramic, but the scale of the fracture increases as the depth of cut increases. . Furthermore, ceramics have poor thermal conductivity compared to metals, and the temperature of the cutting edge of a sintered diamond tool increases during cutting. In particular, the penetration depth at the boundary area is larger than other areas as shown in Figure 2, and the increase in the degree of penetration is significant. of. 1lll'l;Ji1'I diamond has low heat resistance +IU- 700' (g), -1,
Since the wear deteriorates at a temperature of , the temperature JW will rise. In particular, when grinding SI3N4 and S+C, which can be obtained by decomposing at high temperatures and reacting with Kuihe/Send,
l? The wear caused by the reaction in the 1st part is also JA+warudame cheek: l+'i die-\・If you hit the upper back once at the tip of the sword, it will always have an effect on J1: b"Cool the L-bound diamond send for 1' and cut it (tC1,'i A
l! In the formula (i is fine, but in the case of tIy type cutting':
jl, )'i'i I'13 t, -1 1 always V becomes larger. This reason V has 6 gills 71 as shown in the first order. S+3N4 by lino cutting.

SiC and sintered tire sensor l' l-cane temperature is also above y1
However, the strong J law low -1- due to 'f1 is Si
3N4, the power of SiC becomes human in practical terms. t11
! When cutting with the formula, the workpiece is also cooled, so S +
The strength of 3 N 4 and SiC increases;
It got even worse. The effect of the cutting method of the present invention is noticeable when the hardness of the ceramic is 600 or more on the Vickers hardness scale.

If the Vickers hardness is 600 or less, no problem will occur even when wet cutting is performed.

(Silver diamonds are made up of diamond grains bonded to each other, and should have a high diamond content.

The heat sink with the moon is made of paulownia T1, which has high thermal conductivity such as pure copper.
Make it with This can be brought into close contact with the surface of the sintered diamond part of the tool. It is also effective to create a cavity inside the pure copper plate to allow cooling water to flow through it.

1) IjL will be explained by the examples.

(c) Good example of Example 1. Addition of old tire send of lamp carbon whose main component is diamond with average particle size of 20 to 30 μII+ to make Nisso of 13≠.

411 in Fig. 3 (cutting speed 50 of Si3N4 with Vickers hardness 1300 using Cu heat sink)
Dry cutting was performed at a depth of cut of 0.2 mm and a feed of 0.05 mm/rotation for 7 minutes.

lll'1. for comparison. When we examined the tool wear after 1 and 10 minutes of cutting with the above-mentioned tip without cooling the Saba Diamond Send, we found that the wood 5 and the marked wood were O and I O during boundary wear.
am, escape face 1 emotion 11) 1, Q, (18IInt
On the other hand, the comparative product's uniform wear IIJ &:1.
' 0.20 mm, flank face 1 wear tjj is O, l 2
rnm de atatsu/ko.

Example 2 '1 Same as the □b)-Connecting die A1 Monde tool used in Example 1 4
[With this item, the SiC of OO
Cutting speed 801tj/”, penetration fl, :(trrm
Cutting was carried out for 5 minutes at a speed of 0.025 rim/rev. , -1<definite boundary 1ji'j 1(:
lJ, respectively during flank wear) Lo, 2+ynon, 0.
15 am, but the boundary wear and flank jφ wear of the 71-year-old replacement product were 0.4 am, 0, and 25 mm, respectively.
1, 4, I'i'+'i of the drawing 11 ij 1141 Figure 1 and 1 hard 1r'j] I'i' of the tip of the cheek-tied Guiya after cutting the temik f It is a diagram in which Jo1-like deafness is made smaller. Figure 2 shows the cross-sectional shape of JM. Figure 3 shows 1 of the cooling methods for sintering die A/Sen I/-.
This is an example.

■ Sintered diamond 2...Boundary wear 3-flank surface jψEQ 4...Sintered diamond tool 5...II history Ceramic...Cut R'J If Nor surface shape (old line part) 7...Boundary Part 8 Sintered: Tire send 9 Tool holder 10 ・H-1 sink (die i, l) string

Claims (2)

[Claims] (1) Cool only the sintered diamond tip with a heat sink, and then dry cut the hard ceramic with a Vickers grade of 600 or higher.9. A method for cutting hard ceramics with ν characteristics. (2) It is assumed that the hard ceramic is a Si3N4 sintered body or a SiC sintered body as a 4.1J sign! tl'r :i'l
'I) of the hard ceramic according to claim (1)
J rigid force method.