Burr is a common problem in metal processing, such as drilling, turning, milling and plate cutting. One of the hazards of burr is that it is easy to cut! In order to remove burrs, a secondary operation called deburring is usually needed. Three deburring and edge finishing of precision parts may account for 30% of the cost of finished parts. In addition, the secondary finishing operation is difficult to be automated, so burr really becomes a very difficult problem.
1.Chemical deburring
Chemical deburring is processing by using chemical energy. Chemical ions will adhere to the surface of parts to form a film with high resistance and low conductivity, which will protect the workpiece from corrosion. Because burrs are higher than the surface, they can be removed by chemical action. This deburring method is widely used in pneumatic, hydraulic, construction machinery and other fields.
2.High temperature deburring
Firstly, the parts to be deburred are put into a tight sealed chamber, and then the whole parts are sent into the mixed gas of hydrogen and oxygen with a certain pressure, and the mixed gas is ignited to explode and release heat, so that the burrs of the parts are burned without damaging the parts.
3.Roll grinding to deburr
Put the parts and the abrasive into a closed drum. During the rotation of the drum, the dynamic torque sensor, the parts and the abrasive will grind together to remove burrs. The abrasive can be quartz sand, sawdust, alumina, ceramics, metal rings and so on.
4.Manual deburring
This method is more traditional and the most time-consuming and laborious. Mainly through artificial tools such as steel file, sandpaper and grinding head. The most commonly used trimming knife in production now.
5.Process deburring
Edge rounding can refer to all actions to remove the edges of metal parts. However, it is usually associated with the radius at which the edge of the part is created. Edge rounding is not simply to remove sharpness or deburring, but to break the edge of metal parts to improve their surface coating and protect them from corrosion.
Edge fillet machine includes: rotary chamfering: suitable for laser cutting, stamping or machining the edge of parts.
Manual grinding machine: suitable for metal processing projects that need grinding and edge rounding or deburring.
Burr in milling parts with special problems
In milling parts, deburring is more complicated and costly, because milling different positions with different sizes will form multiple burrs. At this time, it is particularly important to choose the correct process parameters to minimize the burr size.
Main factors affecting burr formation in end milling
（1）Milling parameters, milling temperature, cutting environment, etc. will have certain influence on burr formation, and some main factors such as feed speed and milling depth are reflected by plane cutting angle theory and tool tip exit sequence EOS theory.
（2） The better the plasticity of workpiece material, the easier it is to form type I burr. In the process of end milling brittle materials, if the feed rate or plane cutting angle is large, it is beneficial to the formation of type III burr (defect).
（3)When the angle between the terminal surface of the workpiece and the machined plane is greater than the right angle, the formation of burrs can be suppressed because the supporting rigidity of the terminal surface is enhanced.
(4)The use of milling fluid is beneficial to prolong the tool life, reduce the tool wear, lubricate the milling process, and then reduce the burr size.
(5)Tool wear has a great influence on the formation of burrs. When the tool is worn to a certain extent, the arc of the tool tip increases, which not only increases the size of burrs in the exit direction of the tool, but also produces shaped burrs in the cutting direction of the tool.
(6)Other factors, such as tool materials, also have some influence on the formation of burrs. Under the same cutting conditions, diamond tools are more conducive to inhibiting burr formation than other tools.
Then how to effectively deal with the burr when withdrawing the tool?
Try to compress the space generated by burrs—it is an effective method to eliminate the space generated by burrs when retracting the tool. For example, measures such as chamfering can be taken to reduce the space before withdrawing the tool.
Use appropriate cutting conditions to suppress burrs—to minimize cutting residues, you must choose the most suitable tools and cutting conditions. Choose a tool with large rake angle and sharp cutting edge. Improve cutting speed and cutting characteristics. Especially in finishing cutting, the minimum cutting depth and feed must be adopted.
In fact, in the process of processing, burr is inevitable, so it is best to solve the burr problem from the process and avoid too much manual intervention. The use of chamfering end mill can reduce the space for burr generation and effectively remove burr, which is also a very suitable method for burr removal.