In the process of die-casting production, due to the factors such as pressure impact and insufficient clamping force, the burr of zinc alloy die-casting parts is inevitable. In recent years, with the increasing quality requirements of die castings, the requirements for burr are more strict, and deburring methods emerge one after another.

1. Manual deburring

This is also the way commonly used by general enterprises, using files, sandpaper, grinding heads, etc. as auxiliary tools. The file has manual file and pneumatic dislocation. The labor cost is expensive, the efficiency is not very high, and it is difficult to remove complex cross holes. The technical requirements for workers are not very high. It is suitable for products with small burr and simple product structure.

2. Die deburring

Deburring by using the production die with the punch requires a certain production cost of the die (coarse die + fine die), and may also need to make the shaping die. Suitable for products with simple parting surface, the efficiency and deburring effect are better than manual.

3. Grinding and deburring

This kind of deburring includes vibration, sand blasting, roller and other methods. At present, enterprises adopt more methods, which has the problem of not very clean removal. It may need to follow-up manual treatment of residual burrs or cooperate with other methods to deburr. Suitable for small products with large batch.

4. Freezing deburring

The burr is quickly embrittled by cooling, and then the burr is removed by shot blasting. The price of the equipment is about 200000 to 300000, which is suitable for products with small burr {wall thickness and small products.

5. Thermal explosion deburring

It is also called thermal deburring and explosive deburring. By introducing some natural gas into an equipment furnace, and then through the action of some media and conditions, the gas will explode instantly, and the energy generated by explosion will be used to dissolve and remove burrs. The equipment is expensive (millions of prices), the operation technology requirements are high, and the efficiency is low. The side effects (rust and deformation) are mainly used in some high-precision parts fields, such as automobile and aerospace and other precision parts.

6. Deburring of engraving machine

The price of the equipment is not very expensive (tens of thousands), which is suitable for simple spatial structure and simple and regular deburring positions.

7. Chemical deburring

Based on the principle of electrochemical reaction, the deburring operation of parts made of metal materials can be completed automatically and selectively. It is suitable for internal burrs that are difficult to remove, and for small burrs (thickness less than 7 wires) of pump body, valve body and other products

8. Electrolytic deburring

An electrochemical machining method for removing burr of metal parts by electrolysis. The electrolyte is corrosive to a certain extent, and the parts near the burr are also affected by electrolysis, which will lose the original luster on the surface and even affect the dimensional accuracy. The workpiece shall be cleaned and antirust treated after deburring. Electrolytic deburring is suitable for removing the burr of cross holes in hidden parts or parts with complex shape. It has high production efficiency. The deburring time generally takes only a few seconds to tens of seconds. It is suitable for deburring gears, connecting rods, valve bodies and crankshaft oil circuit orifices, as well as sharp corner rounding.

9. High pressure water jet deburring

Taking water as the medium, its instantaneous impact force is used to remove the burrs and flash produced after processing. At the same time, it can achieve the purpose of cleaning. The equipment is expensive. It is mainly used in the heart of automobile and the hydraulic control system of engineering machinery.

10. Ultrasonic deburring

The instantaneous high-pressure deburring generated by ultrasonic is mainly aimed at some micro burrs. Generally, if the burrs need to be observed by microscope, you can try to remove them by ultrasonic method.

Although burr is small, it directly affects the quality of products. Therefore, in recent years, with the attention of various industries to deburring, deburring methods have emerged one after another. There are several kinds of trimming / deburring commonly used at present:

Manual deburring

conventional; The trimming knife gradually replaces these traditional methods, does not need technical treatment, saves cost and environmental protection.

Chemical deburring

Based on the principle of electrochemical reaction, the deburring operation of parts made of metal materials can be completed automatically and selectively. It can be widely used for deburring of pump body, valve body, connecting rod, plunger needle valve and other parts of different metal materials in pneumatic, hydraulic, engineering machinery, oil nozzle, oil pump, automobile, engine and other industries. It is suitable for internal burr difficult to remove, parts after heat treatment and finish machining

Electrolytic deburring

An electrochemical machining method for removing burr of metal parts by electrolysis, which is called ECD for short. The tool cathode (usually brass) is fixed and placed near the burr part of the workpiece, with a certain gap between them (generally 0.3 ~ 1mm). The conductive part of the cathode of the tool is aligned with the burr edge, and other surfaces are covered with an insulating layer to concentrate the electrolysis on the burr part. During processing, the cathode of the tool is connected to the negative pole of DC power supply, and the workpiece is connected to the positive pole of DC power supply. 

A low-pressure electrolyte (usually sodium nitrate or sodium chlorate aqueous solution) with a pressure of 0.1 ~ 0.3 MPa flows between the workpiece and the cathode. When the DC power supply is connected, the burr will be removed by anodic dissolution and taken away by the electrolyte. The electrolyte is corrosive to a certain extent, and the workpiece shall be cleaned and antirust treated after deburring. Electrolytic deburring is suitable for deburring hidden parts, cross holes or parts with complex shapes. It has high production efficiency. Generally, the deburring time is only a few seconds to tens of seconds. This method is often used for deburring gears, splines, connecting rods, valve bodies and crankshaft oil circuit orifices, as well as sharp corner rounding. The disadvantage is that the vicinity of the burr of the part is also affected by electrolysis, and the original luster of the surface will be lost, and even the dimensional accuracy will be affected.

Ultrasonic deburring

When the ultrasonic energy generated by ultrasound acts on the liquid vibrating in a sparse state, it will tear into small holes (i.e. the interior is vacuum). When these holes break, they will produce an instantaneous pressure of up to hundreds of atmospheres, which is called cavitation phenomenon. Ultrasonic deburring is to remove the burrs attached to the parts by using the instantaneous impact force of hundreds of atmospheres produced by the "cavitation phenomenon". Ultrasonic deburring is not applicable to all burrs. It is mainly aimed at some micro burrs. 

Generally, if the burrs need to be observed by microscope, you can try to remove them by ultrasonic method. For the burrs visible to the naked eye, it mainly depends on the bonding strength. The burrs with weak bonding strength can be treated with ultrasonic. Generally, if the burrs can only be treated with tools, the ultrasonic method is not at all. Advantages and disadvantages of ultrasonic deburring.

High pressure water jet deburring

As the name suggests, it takes water as the medium and uses its instantaneous impact force to remove the burrs and flash produced after processing, and can achieve the purpose of cleaning at the same time. After many tests, it is finally found that the suitable pressure is 30mpa-50mpa. If the pressure is insufficient, the deburring effect cannot be achieved. If the pressure is too high, although the burr can be removed, there is a risk of damaging the workpiece. Generally, the liquid pressure borne by hydraulic parts in use is within 20MPa, and the burr residue that cannot be removed with 50MPa pressure has a very small probability of falling off under the working pressure of a few MPa.

 It can also be considered that the root residue of burr is a part of the workpiece. Now there are more and more manufacturers of high-pressure water deburring equipment, which can be simply divided into two categories: workpiece moving type and nozzle moving type. The workpiece moving type has low cost and is suitable for deburring and cleaning of simple valve body. Its disadvantage is that the matching degree between nozzle and valve body is not ideal, and the deburring effect of cross hole and inclined hole in valve body is not good; The movable nozzle can effectively adjust the distance between the nozzle and the burr generating part of the valve body through CNC control, and effectively correspond to the burr of the cross hole, inclined hole and blind hole in the valve body. However, due to the high cost of this equipment, so far, only the heart of the automobile and the hydraulic pressure control system of engineering machinery can generally enjoy this kind of treatment.

Thermal explosion deburring

Also known as electro thermal deburring, thermal deburring is an advanced process recognized by the world's machinery manufacturing industry as the most suitable for deburring small workpieces in large quantities. At present, only two domestic enterprises can produce this equipment. It uses hydrogen and oxygen to mix in the closed working chamber used to treat the workpiece, ignites and burns instantaneously, and has a violent thermochemical reaction with the burr on the workpiece surface in a very short time, so as to achieve the purpose of burr removal. 

Thermal deburring is a special processing technology, which has the characteristics of high efficiency, strong universality, good accessibility, uniform and complete deburring, flat and smooth workpiece surface, and is not limited by workpiece material, shape and burr position. It is especially suitable for deburring of workpiece with complex cavity, intersecting hole system, deep hole, blind hole, threaded hole and other difficult deburring problems that cannot be solved by other process methods. It can be used for deburring of non-metallic materials such as black, non-ferrous metals and thermoplastics, and deburring of metal die castings and plastic die castings. Because of its high processing efficiency and low direct cost for production, it is especially suitable for mass continuous production environment. It is an ideal and efficient processing equipment for large-scale industrial production.

Cold trimming and deburring

The thickness of flash (or burr) of rubber, plastic products, zinc magnesium aluminum alloy and other products is much thinner than that of the products, so the embrittlement speed of flash (or burr) is faster than that of the products. During the time period when flash (or burr) is embrittled but the products are not embrittled, the frozen deburring (trimming) machine strikes the products by shooting bullets to remove the embrittled flash (or burr).

 Frozen deburring (trimming) machine is a kind of machine that uses the ultra-low temperature of liquid nitrogen to embrittle the flash of rubber, plastic products and zinc magnesium aluminum alloy rapidly, and in this state, the frozen particles sprayed at high speed impact the burr (or Flash) of the product, so as to remove the burr (or Flash) of the product with high quality and high efficiency, Special deburring (trimming) equipment that can keep the physical properties of the products unchanged. It can greatly improve the trimming (deburring) accuracy of products and has a high degree of intensification. At present, this equipment has become an indispensable post trimming and deburring equipment for precision rubber and plastic products and die-casting enterprises.

Magnetic deburring machine

Magnetic deburring machine uses its unique magnetic field distribution to produce strong and stable magnetic induction effect, so that the magnetic steel needle (imported raw materials. Semi permanent) can be fully ground with the workpiece in an all-round and multi angle way, so as to achieve the effects of rapid rust removal, dead angle removal, deburring and cutting edge removal, oxidation film removal and sintering trace removal. Especially for complex shape, porous crevices, internal and external threads and other workpieces, it can show its magical function In addition, it will not damage the surface of the workpiece and affect the accuracy of the workpiece. 

Let the workpiece become smooth, tidy and new in an instant. It is suitable for grinding, polishing and deburring of metal workpieces such as gold, silver, copper, aluminum, zinc, magnesium, iron and stainless steel and non-metallic workpieces such as hard plastics at one time!

Source: my color