By integrating flexible hones in the machining process, complex aerospace parts with cross-drilled holes and other difficult-to-access features can be deburred, honed, surface finished, etc. in-house, at less cost.
“Eliminating burrs is critical because if any loose material gets dislodged during use, there can be serious consequences,” says Garaczi.
According to Garaczi, the tool he has selected for such applications is the Flex-Hone from Los Angeles-based Brush Research Manufacturing (BRM). Characterized by the small, abrasive globules that are permanently mounted to flexible filaments, the product is a flexible, low-cost tool utilized for sophisticated cross hole deburring, honing, surfacing, and edge-blending. The hones are available in a variety of abrasive types, sizes, and grit selections.
“For deburring holes and honing when we need to clean up a component, it is the easiest tool to use for us. There is a large variety of grades and sizes and it is very versatile,” says Garaczi,
In such applications, flexible hones are ideal because the tools are a cost-effective solution to smooth edges and produce a blended radius for crosshole deburring.
“In terms of accessibility, I haven’t found any other tools that can do what a Flex-Hone can, whether for multiple cross holes or internal grooves, says Garaczi. “There is really no way to effectively reach those areas with any sort of other tool.”
He adds, “Right now, we are making more and more complex aerospace parts, especially when it comes to housings with ports all over the part. That is where the hone comes in really handy – for deburring the holes where you drill into it.”
For best results, the deburring tool is typically rotated into the main bore into which the cross holes break. After a few clockwise strokes, the tool is removed and the spindle reversed to rotate and stroke the flexible hone in a counterclockwise direction for a few more strokes. The forward and reverse rotation creates a symmetrical deburring pattern. Coolant should be used to keep metal cuttings and deburred metal in suspension.
According to Garaczi, removing burrs can be particularly problematic when dealing with machined superalloys used in aerospace, such as titanium, Monel, Inconel, Incoloy, Invar, Rene and Hasteloy, which are some of the most difficult materials to machine.
“The burrs are one of the biggest problems, particularly when machining superalloys” adds Garaczi. “Even during ‘grooving,’ if you cut the material from one side, it just pushes the burr to the edge; and if you approach it from the other side, it just pushes it back. It doesn’t want to break off the material cleanly. As soon as the tool gets a bit dull it gets a lot worse. So, sharp tools with the right geometry are key.”
Garaczi notes that the Flex-Hone is available with a premium nickel-coated diamond abrasive for use on materials like carbide, ceramic and aerospace steel alloys; as well as a CBN (Cubic Boron Nitride) option that is even harder and is specifically designed for superalloys, which can exhibit high ductility and work hardening that produce a gummy machining behavior if the correct abrasive tool is not utilized.
According to Garaczi, when deburring superalloys such as titanium or 13-8 stainless alloy, utilizing the Flex-Hone has been very helpful. “Most of the 13-8 we machine is heat-treated, so it is subject to significant burrs. The hone is ideal for removing even the most stubborn burrs,” says Garaczi.
Garaczi points out that he is installing the flexible hones into CNC equipment to automate the process and reduce the time required to finish superalloys and stainless steels.
Despite the fact that these are abrasive tools, Garaczi says that even though “abrasives” are often all lumped into the same category, a distinction must be made between abrasives used for aggressive material removal and abrasive finishing tools. Finishing tools release little to no abrasive grit during use, and the amount generated is comparable to the metal chips, grinding dust and tool abrasion created during the machining process itself.
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Hi,
I'm interrested in your honing product that can integrated in a cnc milling machine.
However, I am concerned about the contamination of the coolant by the abrasive residue left by this type of equipment which could quickly degrade the machine.
How do you prevent this situation?
Regards,
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