Cold spray technology is applied to the deburring process

‘‘Burrs are everywhere in the machining process, and no matter how advanced and sophisticated the equipment you use, it will be born with the product.

Before and after deburring                                                     

Problems caused by burrs

burrs on mechanical parts, some of which are caused by plastic deformation during the cutting process; Some are flashes for casting, die forging and other processing, and some are remnants of welding extrusion. Burrs have a significant impact on the quality and performance of a workpiece, and here are some of the problems that can be caused by the presence of burrs:

  • Safety is reduced, and sharp metal edges pose a danger to the operator.
  • The increase in pressure during operation leads to a decrease in the resistance of the workpiece to breakage and fatigue.
  • Susceptible to corrosion, which is related to the difference in the thickness of the material.
  • Lubrication issues, especially due to contamination of burr debris and wear around the interface perimeter.
  • Interference occurs when finishing processes such as powder coating or electroplating are carried out.

Burrs in drilled holes can lead to fastener and material problems. Burrs cause more stress to be concentrated on the edge of the hole, reducing fracture resistance and shortening fatigue life. They can interfere with the fastener’s fixation, which can damage the fastener or the component itself. Cracks caused by stress and strain can lead to material failure. Burrs in the holes also increase the risk of corrosion, which can be due to variations in coating thickness on rough surfaces. Sharp corners tend to concentrate charges, increasing the risk of electrostatic discharge. Burrs in moving parts add unnecessary friction and heat. Rough surfaces can also cause lubrication issues as wear increases at the interface of the part. This makes it necessary to replace them more often, and charge build-up can also lead to corrosion. Burrs can be present in the form of filaments on the edges of freshly ground tools or as raised parts of the surface. The deburring process accounts for a large portion of the manufacturing cost.

How to fix it

During the design and manufacturing engineering phase of product development, burrs can be reduced or prevented by considering materials, functions, shapes, and processes.

Before and after deburring

Deburring treatment

There are many deburring processes for finished parts, such as several common batch polishing, dry ice cold spraying technology, spindle finishing, media sandblasting, grinding, grinding, wire brushing, abrasive flow processing, electrochemical deburring, electrolytic polishing, thermal energy method, machining and manual deburring, etc.

The table below compares the different deburring processes

In summary, the comparison of deburring processes was carried out, and the dry ice cold spraying technology was selected as the best deburring process application.

Why dry ice deburring technology

Dry ice cleaning burr principle

Dry ice pellets are used to mechanically remove burrs from molded parts that have become brittle through pre-cooling. Utilizing the impact action of dry ice particles. The cleaning effect is determined by the speed as well as the size and density of the dry ice particles and the quality of the dry ice. Dry ice particles transfer heat from the dry ice particles to the corresponding burrs when they hit the burr, creating a significant temperature gradient in the burrs and a correspondingly high shear force, which helps to remove the burrs. Finally, the sublimation of dry ice particles produces gaseous CO upon impact, which occupies significantly more volume than solid dry ice particles. This explosive increase also brings a pulse to the point of impact, which helps in the removal work.

Comparison of metal parts before and after deburring

Four reasons to deburr with dry ice

The dry ice deburring process uses dry ice particles accelerated by compressed air to remove burrs and burrs from plastic and metal parts. Dry ice sublimates (converts from solid to gas) when it hits the surface of the part, so that the cleaning process essentially eliminates the need for additional media.

Dry ice deburring is recommended for parts with small holes or cavities, thick flash burrs, and challenging burr or curl positions. For parts that are too large or too heavy to tip over, the dry ice cold spray process is also a good choice.

Because dry ice cleaning uses a single part wash rather than a mixed part wash, it provides a more straightforward cleaning effect than other processes. In addition, dry ice cold spray cleaning can achieve higher compatibility, with up to 140 PSI cleaning pressure adjustment. High-velocity dry ice media pellets can remove heavy plastic burrs, fine metal burrs, and other undesirable part burrs.

Comparison of parts before and after deburring

Some parts have hard-to-reach burrs, such as deep, narrow through-holes, that need to be handled at precise angles. When the opening of the hole is narrow, the area that can be washed by the media-driven batch method becomes shallow. For parts that are particularly challenging in flash or burr locations, dry ice deburring is an effective option.