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CBN (cubic boron nitride¨CHistory )
CBN: the second hardest material. Although diamond acts as the hardest material in the world, it is not suitable for processing metal alloy due to its chemical affinity to carbon. So another kind of material, the so-called CBN is developed. Cutting edges, which are made of CBN, cover an even wider application range. The hardness of CBN is less than diamond and stands at the second place, that is to say, the hardness of CBN at 1000 ˇć is still equal to the hardness of hard alloy at 25 ˇć . As PCD the hardness of CBN is based on its connection between crystals. Hard alloy, which acts as carrier for CBN, is used into all kinds of cutting edges. Such cutting edge can stand very high cutting pressure, so it can cut very hard and tenacious materials. Besides, the tightly connected crystals can bear huge impact force, a precondition to cut discontinuous surface. Compared to carbide materials and especially ceramic material, CBN has an outstanding diathermancy. Therefore when turning and milling, it can transmit heat better than hard alloy- and ceramic cutting edges. |
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When processing hard, tenacious and debris-intensive materials, the material surface will become very hot by high cutting frequency, attenuation will occur by inserts made of common materials. But inserts made of CBN won't. Even at a temperature of 1000 ˇć the cutting edge still hold its original hardness and tenacity, furthermore oxidation and chemical reaction with iron, nickel, cobalt and etc. won't take place. |
Relative abrasion resistance
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Characteristic:
The hardness of CBN is the second hardest material after diamond. But compared with diamond, there isn't any chemical reaction when processing iron metals. Under high temperature and high pressure the hard alloy, which acts as carrier, can be coated with a tight polycrystalline CBN. This kind of polycrystalline CBN is called PCD.
BZN* inserts are developed to replace the traditional milling process. For hard steel materials (HRC 45-68) high cutting speed of 80-200 m/min can also be reached.
BZN* insert can also cut perlitic cast iron and alloy. | Feature and application
| BZN8100 |
Soft 2 my
60% CBN, ceramic-connection |
Turning, milling of hard steel
(HRC 45-68) |
| BZN8200 |
Soft 2 my
60% CBN, ceramic-connection
corn -corn-connection |
Turning, milling of hard steel
(HRC 45-68) also for discontinuous cutting |
| BZN6000 |
Hard 2 my
96% CBN, Metal-connection |
Turning and milling of sinter Stahl, perlitic, hard cast and alloy cast |
| BZN7000 |
Hard 15 my
82% CBN, ceramic-connection |
Rough and fine processing of perlitic and hard steel |
PCD cutting process parameter
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material
Hard steel (HRC 45-68)
tool steel,
continuous- and discontinuous cutting |
Cutting speed
Pre-turning
fine turning
milling |
V(m/min)
80-130
80-180
70-500 |
cutting depth ap (mm)
1,0-2,5
0,1-1,0
0,1-1,0 |
Feed f (mm/U)
0,1-0,5
0,03-0,2
0,05-0,3 |
8100 X |
8200 0
X |
6000 X
X
X |
7000 0
X |
| Perlitic cast iron |
Pre-turning
fine turning Milling |
500-1000
600-3000
600-5000 |
0,5-3,0
0,05-0,5
0,5-3,0 |
0,3-0,6
0,05-0,5
0,1-0,3 |
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X
X
X |
X
X
X |
Hard cast
Ni-Hard
chrome cast |
Pre-turning
fine turning
milling |
40-100
40-120
100-200 |
1,0-4,0
0,1-1,0
0,1-2,5 |
0,1-0,5
0,1-0,3
0,1-0,2 |
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X
X
X |
X
X
X |
Hard metal
more than 18% Cobalt |
Pre-turning
fine turning
milling |
20-25
20-25
20-25 |
0,2-1,0
0,1-0,5
0,1-0,6 |
0,1-0,4
0,1-0,3
0,1-0,3 |
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X
X
X |
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Super alloy (Inconell, Waspaloy, Colmoloy),
Exotic steel on Nickel or cobalt base |
Fine turning
milling |
80-150
100-200 |
0,05-0,5
0,1-1,5 |
0,03-0,2
0,05-0,3 |
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X
X |
X
X |
X=very suitable
0= suitable with condition
milling feed value = mm / tooth
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Please pay attention to the following rules:
in case of small feed between 0,03 to 0,05 and small cutting depth between 0.1 to 0.2 and high cutting speed the life of the cutting edge will be shortened significantly.
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| BZN8100 |
BZN8200 |
BZN600 |
BZN7000 |
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