Internal Cross Hole Deburring
Is there a reasonably priced deburring system that can handle four-inch deep cross holes in aluminum aerospace machined parts?
Q. We have three full time deburring operators that are hand deburring aluminum aerospace machined parts with three and four-inch deep cross holes. This is very difficult and time consuming work. Is there a reasonable priced deburring system that can help us? –R.S.
A. Internal burr removal in the aerospace industry is critical. Aerospace contractors require procedures for deburring and inspection.
Procedures include developing levels of part deburring difficulties and matching them with the appropriately trained operators. For example, if you’ve developed level one through seven parts with seven being the most difficult; a level seven part must be deburred with a level seven trained operator. A level five operator cannot deburr a level seven part.
When a part has multiple holes requiring deburring, the holes are deburred in a prescribed sequence. There is a deburring procedure for each hole.
An inexpensive internal deburring system that would help you significantly is electro chemical deburring (ECD). These systems flow a low DC current with a five percent salt solution to the burr and dissolve it. It is very efficient and precise. Systems can cost less than $20,000 for a handheld system that runs one part at a time or a fixture process that runs multiple parts at a time. These systems will shorten deburring times significantly with more accurate results than chasing a burr back and forth by hand to remove it.
Other systems that can be considered for internal hole deburring are Thermal explosion deburring or systems that forces an abrasive flow through the area. Both systems work, but are more of a financial commitment than ECD deburring.
An ECD system is the most competitive solution to metal internal cross- hole deburring. ECD works on most metals, however, does not work on plastic or composite materials.
Plastic and composite internal cross holes can be removed with small pressure blasting systems with fine nozzles that are designed to reach into the areas. Dry ice blasting also works well by freezing the burrs and then forcing them out.
Immersion tin and lead-free hot air solder leveling (HASL) coatings based on SnCu or SnAgCu alloys are widely used as surface finish materials for printed circuit boards (PCB). These coatings prevent the underlying copper from corrosion and preserve its solderability during lead-free assembly processes and for a long storage life of PCBs.
Advances in equipment, automation and consumables can help you compete.
When choosing vibratory media, understand the size, shape, starting roughness condition and metallurgical structure of the part.