Carbide Cutting Tool Hardness, Toughness, Strength, Wear Resistance
As the Carbide Cutting Tool material wear resistance and toughness is not easy to take into account, so the user can only according to the specific processing objects and processing conditions in a number of carbide grades to select the appropriate tool material, which gives Carbide Cutting Tool selection and Management brings a lot of inconvenience. In order to further improve the comprehensive cutting performance of cemented Carbide Cutting Tool materials, the current research hotspots mainly include the following aspects:
1) refine the grain
By refining the grain size of the hard phase, increasing the interfacial surface area of the hard phase and enhancing the intergranular bonding force, the strength and abrasion resistance of the cemented Carbide Cutting Tool material can be improved. When the WC grain size is reduced to below submicron, the hardness, toughness, strength, abrasion resistance and so on of the material can be improved, and the required temperature for complete densification can be reduced. Ordinary hard alloy grain size of 3 - 5μm, fine grain cemented carbide grain size of 1--1.5μm (micron level), ultrafine grain cemented carbide grain size of up to 0.5μm below (sub Micron, nanometer). Ultrafine grain cemented carbide and composition of the same ordinary carbide compared to the hardness can be increased above 2HRA, bending strength can be increased by 600--800MPa.
Commonly used grain refinement process methods are physical vapor deposition, chemical vapor deposition, plasma deposition, mechanical alloying and so on. Isometric lateral extrusion (ECAE) is a very promising grain refinement process. The method is to place the powder in the mold and squeeze it in a direction that is different (and not opposite) from the extrusion direction, and the cross-sectional area at the time of extrusion is constant. The crystal grains processed by ECAE process can be refined.
As the above grain refinement process is still not mature enough, so in the cemented carbide sintering process is easy to grow into coarse grains, and the general growth of grain will lead to material strength decreased, a single coarse WC grains are often An important factor in material fracture. On the other hand, the price of fine grain cemented carbide is more expensive, its promotion and application also play a certain role in restricting.
2) coated carbide
The coating is coated with a thin layer of wear-resistant metal compound by CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), HVOF (HighVelocity Oxy-Fuel Thermal Spraying) So that the strength of the matrix and the wear resistance of the coating combined to improve the overall performance of carbide cutting tools. Coated Carbide Cutting Tool has good wear resistance and heat resistance, especially for high-speed cutting; because of its high durability, versatility, for small quantities, multi-species of flexible automated processing can effectively reduce the number of tool changes , Improve the processing efficiency; coated carbide cutting tool resistant to crescent wear, tool edge and groove stability, chip breaking effect and other cutting performance is reliable, is conducive to the automatic control of the process; coated carbide cutting tool After the passivation of the substrate, after the refinement of high dimensional accuracy, to meet the automated processing of the tool positioning accuracy requirements. The above characteristics determine the coating Carbide Cutting Tool is particularly suitable for FMS, CIMS (computer integrated manufacturing system) and other automated processing equipment.