PCBN tool materials and other types of tool materials, due to the composition of different, with many brands, suitable for different purposes. The performance of PCBN is related to the content, particle size, and type of binder of CBN. By adjusting the content, grain size, binder ratio and type of CBN, PCBN tools with different properties and different processing requirements can be obtained.
(1) PCBN tools can be divided into two categories according to the added components:
One is directly made of CBN single-crystal hot pressing and sintering, CBN content is more (more than 70%), high hardness, suitable for heat resistant alloy, cast iron, and iron series sintering metal cutting and adding. The other is the hot pressing body formed by sintering CBN grain with a certain proportion of ceramic binder (mainly TiN, TiC, TiCN, AlN, Al2O3, etc.). This kind of PCBN has less CBN content (less than 70%) and lower hardness, which is suitable for the cutting of hardened steel.
(2) there are three main types of the binder for PCBN:
Metal binder, composed of metal or alloy, such as Co, Ni, etc., metal binder PCBN sintered body has good toughness and conductivity, the disadvantage is that under high-temperature binder softening, wear resistance decline. Ceramic binder, such as A1 203, etc., the sintered body of ceramic binder PCBN has a high resistance to high-temperature wear and loss and strong resistance to adhesion, which solves the problem of metal binder softening at high temperature, but its impact resistance is poor and brittleness is large. Cermet, such as TiN, TiC, TiCN, AlN, etc., solve the above problems and have better comprehensive performance.
(3) PCBN cutter can be divided into:
Overall PCBN hot pressing block and carbide composite hot pressing PCBN composite sheet. The overall PCBN blade is rigid, suitable for rough machining. The cost of composite PCBN blade is low, suitable for finishing, or semi-finishing.
(4) existing studies have shown that the cutter prepared with pure CBN material cannot obtain the best processing effect in many cases. And the content of CBN is generally between 50% and 95%.
The content of CBN mainly affects the hardness and thermal conductivity of PCBN. With the increase of the content of CBN, the hardness, wear-resistance and thermal conductivity of PCBN increase, while the toughness decreases. When the content of CBN is less than 50%, the hardness of PCBN decreases, leading to plastic deformation of cutting edge and blade breakage. When the content of CBN exceeds 95%, PCBN performance becomes poor, brittleness increases, CBN grain is easy to fall off, wear resistance is greatly reduced.
Demina PCD tool grinding machine is can grind the CBN material with a fine finish.