Dry cutting technology
13 3月 2018 | 没有评论 | posted by admin | in Article
Dry-cutting technology is proposed with the development of ceramic cutting tools. With regard to environmental protection considerations, no cutting fluid is used. The auxiliary heating device is used to locally heat the surface of the workpiece (such as laser heating, conductive heating, etc.) to a certain temperature to improve the material. The machinability reduces the cutting force and contributes to the realization of dry cutting. However, this technology places high demands on the heat resistance (red hardness) of the tool for a long period of time. Therefore, it is currently only applicable to a ceramic tool that can maintain its strength and hardness at high temperatures for a long period of time.
Dry cutting is currently not a universal technology due to the influence of the current process conditions, workpiece materials and processing types.
TiC coating
12 3月 2018 | 没有评论 | posted by admin | in Article
TiC coating has high hardness and wear resistance, good oxidation resistance, can form titanium oxide film during cutting to reduce friction coefficient, reduce tool wear, make cutting speed increase by more than 40%, and is more suitable for high-speed cutting. The TiC coating has a high bonding temperature with the steel, the surface grains are very fine, and the built-up edge is rarely generated during cutting, which is suitable for high-speed precision turning. The disadvantage is that the coefficient of linear expansion differs greatly from that of the base body. Therefore, the coating tends to crack when high-speed turning or milling of hard materials, high-temperature alloys or workpieces with inclusions.
High speed cutting characteristics – low cutting force, low vibration frequency
10 3月 2018 | 没有评论 | posted by admin | in Article
The process of cutting formation is divided into two stages: extrusion plastic deformation and tearing. The plastic deformation of the workpiece due to cutting forces and cutting heat is mainly at this stage. It can be seen that the higher the cutting speed, the shorter the plastic deformation time, the narrower the shear deformation region, the larger the shear angle, the smaller the deformation factor, and the faster the chip flow rate (80% of the heat of cutting is accounted for by the heat in the chip). The smaller the heat input to the workpiece and the tool, the higher the speed of cutting can be, the average reduction of the cutting deformation rate is 30-40%, which is very suitable for the machining of poor rigidity and thin-walled parts.
From the dynamic analysis of frequency formation, it can be seen that the reduction of cutting force will reduce the amplitude of the vibration (ie, forced vibration) due to the cutting force. The increase of the rotational speed makes the working frequency of the cutting system away from the low-order natural frequency of the machine tool to avoid resonance. Therefore, high-speed cutting can greatly reduce the surface roughness and improve the quality of processing.
