Cubic Boron Nitride (CBN)
Cubic Boron Nitride (CBN) is second to diamond in hardness on the earth, and has high wear resistance and high thermal stability.
To be complementary to diamond, CBN is used in machining ferrous materials like steel and iron.
CBN micron powder can be further sintered to Polycrystalline Cubic Boron Nitride (PCBN), including solid PCBN and PCBN compact, as cutting tools.
Polycrystalline Cubic Boron Nitride (PCBN)
Features of CBN Material
High hardness and wear resistance
- The hardness of CBN single crystal is HV 7000 to HV 9000, therefore, it has higher wear resistance than cemented carbide and ceramics when it is used to process high-hardness materials, and can reduce the dimensional deviation in the processing of large parts, especially suitable for equipment with a high degree of automation, thus reduces the auxiliary time for tool change and tool adjustment, so the efficiency can be fully exerted.
High thermal stability
- The heat resistance of CBN can reach 1400℃ to 1500℃, when the cutting temperature is high, the processed material will be softened, and the difference in hardness between the tool will be increased, which is conducive to the cutting process without big effect on the tool life.
High chemical stability
- It has high antioxidant capacity, no oxidation occurs at 1000℃, and it will not chemically react with iron-based materials at 1200-1300 ℃.
High thermal conductivity
- The thermal conductivity of CBN is lower than diamond but much higher than cemented carbide, and the thermal conductivity of PCBN tool continues to increase with the increase of cutting temperature, so the heat at the tip of the tool can be quickly transmitted, which is beneficial to the machining accuracy improvement of the workpiece.
Lower coefficient friction
- The friction coefficient of CBN is 0.1 to 0.3, which is much lower than that of cemented carbide (0.4 to 0.6), and decreases slightly with the increase of friction velocity and positive pressure. Therefore, the low friction coefficient and excellent anti-adhesion ability make it not easy to form a built-up edge when cutting, which is beneficial to improve the quality of machined surface.
Applications of PCBN tools
PCBN is ideal for machining ferrous materials, and PCBN tools have been widely used in machining the followings:
- Hardened steel: wind power bearing, slewing bearing, industrial gear, transmission gear, drive shaft, crushing hammer cylinder, etc.
- Grey cast iron: belt pulley, cylinder block, cylinder head, gearbox housing, etc.
- Alloy cast iron: brake disc, brake drum, cylinder liner, etc.
- Chilled cast iron: roller, slag pump parts, etc.
PCBN Grades
Grade name
Machining method
Material machined
Applications
290
finishing
cast iron
brake disc, brake drum, compressor flange
300
semi-finishing / roughing
hard steel / cast iron
roll, grinder roll, bearing, cylinder liner, industrial pump, brake disc, brake drum
320
finishing
hard steel / cast iron
ball screw, brake disc, brake drum, bearing, gear, compressor flange, transmission shaft
330
finishing
cast iron
brake disc, brake drum
620
finishing / semi-finishing
hard steel
ball screw, bearing, gear, transmission shaft
800
finishing / semi-finishing (wet cutting)
cast iron
brake disc, brake drum, gearbox housing, engine cylinder head, cylinder liner, cylinder
900
finishing
cast iron
brake disc, brake drum, flywheel
PCBN Tools Categories
Name
Catagories
References
ABS
Solid PCBN
BSW
Solid PCBN Welded
BCW
PCBN Compact Welded
- Solid PCBN Insert (ABS): the whole blade is made of CBN powder sintered, with multiple cutting edges, both the top and bottom tips can be used for cutting, and the utilization rate of the blade is high. In addition, the blade has high bending strength, can withstand large depth of cut and high-speed cutting, is suitable for continuous and intermittent cutting, and can meet rough, semi-finishing and finishing.
- Solid PCBN Welded Insert (BSW): the insert is in welding form, with high welding strength, and the center hole is positioned, which can replace the coated blade. It is suitable for machining conditions with a depth of cut <2mm, light intermittent and continuous machining, and can be used for semi-finishing and finishing.
- PCBN Compact Welded Insert (BCW): the PCBN compact blank are cut to small tips and welded to the cemented carbide body to form various turning inserts and boring inserts. Generally, only one cutting edge is available, which is mainly used for finishing conditions.
For more information such as ISO designation and dimensions, please refer to the product catalog of Polycrystalline Cubic Boron Nitride (PCBN) Inserts or feel free to send us an inquiry.