2 single coating
TiC and TiN are the earliest tool coating materials, and they are also widely used at home and abroad. TiC coatings have high hardness (up to HV2500~4200), high mechanical wear resistance and abrasive wear resistance, lower friction coefficient, lower cutting force and lower cutting temperature than uncoated tools. It has good resistance to flank wear and anti-crater wear, and its application temperature is 500 °C, but its brittleness is not resistant to impact. TiN coating is the most mature and widely used hard coating material. Its outstanding advantages are low friction coefficient and application temperature up to 600 °C. It is suitable for processing steel or cutting materials that are easy to stick to the rake face. At present, domestic and foreign tool companies have these two coated grades.
The chemical vapor deposition (CVD) Al2O3 coated tool has higher cutting performance than TiN and TiC coated tools, and the higher the cutting speed, the greater the tool durability. When cutting steel parts in high speed range, the hardness of Al2O3 coating is lower than that of TiC coating at high temperature. Al2O3 has better chemical stability and high temperature oxidation resistance, so it has better resistance to crater wear and flank resistance. The ability to withstand wear and deformation of the edge of the thermoplastic, high durability at high temperatures. In the first generation of Al2O3 coated cutting tools, the coating often consisted of a mixture of a- and κ-Al2O3, resulting in a non-uniform coating morphology that severely degraded coating performance. In the past 10 years, great progress has been made in controlling the nucleation and fine-grain microstructure of a-Al2O3 crystals. Early a-Al2O3 coatings were hot cracked and brittle. Recently, by adjusting the chemical action of the surface of the crystal nucleus, it is possible to completely control and nucleate the a-Al2O3 phase to form a coating composed of fine particles a-Al2O3, avoiding The transformation crack exhibited excellent toughness as compared with the a-Al2O3 coating obtained in the prior art.
The insulating properties of the Al2O3 coating make the physical vapor deposition (PVD) process quite difficult to control and the deposition rate is very low. How to prepare the Al2O3 coating by the PVD method has always been a concern of the tool coating industry. The high ionization pulse technology (HIPTM) developed by CemeCon enables excellent AlOx coatings. The company's newly developed Al2O3 coating based on magnetron sputtered TiAlN coatings has a coating temperature below 450 °C and has achieved satisfactory results in cast iron and high performance and alloy materials.
The thermal expansion coefficient of HfN is very close to that of the cemented carbide substrate. The thermal stress generated after coating is small, the bending strength of the blade is reduced less, the risk of chipping due to different thermal expansion coefficients is reduced, and the thermal stability and chemical stability of HfN are reduced. It is much higher than many high melting point materials. It still has high hardness (30GPa) at temperatures up to 817~1204°C and good wear resistance. At present, the blades of the US Teledyne company with the labels HN+ and HN+4 and the blades of the German Walter company WHN are all HfN coated blades.
Due to the affinity between TiC and TiN coatings and titanium alloys and aluminum alloy materials, the friction and bonding increase, resulting in sticky chips, while the chemical stability of CrC, CrN and newly developed coatings such as Mo2N and Cr2O3. Good, not easy to produce sticky chips, suitable for cutting titanium, copper, aluminum and their alloy materials. In addition, common single-coat materials are NbC, HfC, ZrC, ZrN, BN, VN, and the like.
Previous Next
1.8G Guided Wave Radar Level Meter
1.8G Guided Wave Radar Level Meter,High Precision Flow Rate Meter,1.8G Liquid Level Gauge,High Precision Flow Volume Meter
Jiangsu Pinpai Technology Co., Ltd. , https://www.jspingpa.com