Common problems and selection countermeasures of cutting oil application in stainless steel middle frame machining of mobile phone
January 06, 2022
Recently, the application of the stainless steel middle frame of mobile phones has become more and more popular. The current processing methods of the stainless steel middle frame of mobile phones, such as pure CNC, CNC+ forging, etc., will cause deformation problems regardless of the process. In addition to the problem of deformation, the process is also very complicated for stainless steel processing. A whole piece of stainless steel is hollowed out on a CNC machine tool, leaving only the integrated stainless steel frame. During this period, it has to go through nearly 30 kinds of tools and hundreds of steps with extremely high technological requirements.
The processing of the stainless steel middle frame of the mobile phone is fine processing. When cutting, it is mainly hoped to improve the processing quality while reducing tool wear. Generally, cutting fluids with good lubricating effect should be selected, such as high-concentration emulsions or cutting oils. Common problems of cutting oil application. 1. The oil product has low extreme pressure, which causes the tool to wear quickly, and the finish of the workpiece cannot meet the requirements; 2. Highly corrosive, causing yellowing and rusting of equipment and workpieces, which is extremely harmful to the environment and employee health; 3. The equipment is easy to "yellow robe". Select the 4 major functions of cutting oil to focus on. In the stainless steel cutting process, the cutting is performed on the new surface every time, the speed varies from a few millimeters to hundreds of meters per minute, and the pressure is as high as 2 to 3 GPa. In addition to friction during cutting, there is also intramolecular friction between the tool and the cut metal. The interface temperature of the cutting zone can reach 600-800°C. Such high temperature and high pressure will reduce the strength and hardness of the tool, so the cutting oil must have the four functions of cooling, lubrication, cleaning and rust prevention.
1. Cool It is manifested in reducing the temperature of the tool tip, suppressing the thermal expansion of the material to be cut and the tool, in order to improve the operating performance and processing accuracy.
2. Lubrication Reduce the friction between the rake face and chips, the flank face and the machined surface, prevent adhesion, buildup, scales or cold welding, so as to reduce power consumption and tool wear, and get a better surface finish
3. Anti-rust In order to prevent the water and oxygen in the atmosphere from rusting the newly processed surface, an anti-rust agent should be added to the cutting oil to improve the anti-rust performance of the cutting oil to meet the needs of short-term protection of the workpiece during the processing.
4. Cleaning The liquid flow is used to flush away the fine chips and powder to prevent sticking, so as to ensure the continuous processing of the tool and the workpiece. In the grinding process, cutting oil with poor cleaning properties can cause blockage of the grinding wheel, increase the temperature of the grinding area and burn the workpiece. The use of low-viscosity oil and the addition of surfactants can improve the cleanability of cutting.
