Coventry based engineering company invest in Cogsdill Burnishing Technology
Cogsdill supply innovative Diamond Burnish Face Mill Tools to one of the Industry’s leading suppliers who have over 60 years of experience in the automotive, aerospace, pharmaceutical and food industries manufacturing a broad spectrum of parts in a variety of materials.
The application on this occasion is a pharmaceutical component which has a critical requirement for a flat surface with a finish of 0.8 Ra or better.
(A surface finish requirement of 0.2 Ra or better is typically a burnished finish).
The material is 304 Stainless Steel.
The existing manufacturing process was such that maintaining surface finishes was not consistent, resulting in an additional operation being required for off line polishing by hand, which is not only inefficient but costly in man hours and resources.
The Cogsdill DBFM Tool provides a mirror like finish on flat faces to achieve superior surface finishes.
This was proving to be very time consuming and was taking days to complete a batch of work through the polishing process.
Using Cogsdill’s proven diamond insert geometry, the premium range of burnishing tools can achieve low RA surface finishes, by cold flowing the peaks into the valleys in one pass – achieving results not attainable from any other metal removal process.
Simple and efficient, Cogsdill DBFM tools are designed to produce mirror-like finishes on any surface; from carbon steels to tool steels, cast iron to alloys, and most ferrous and non-ferrous metals.
Set up and operation is relatively simple, with no special operator skills required.
The actual Burnishing process with this tool will be the same as with all burnishing tools.
Burnishing is a surface finishing technique in which a hardened roll is brought into pressure contact with a softer piece part. As the pressure generated through the roll exceeds the yield point of the piece-part material, the surface is plastically deformed by cold flowing of sub-surface material. The result is a mirror-like finish and a tough, work-hardened surface with load-carrying characteristics that are superior to finishes obtained by abrasive metal-removal methods.
A burnished surface is smoother and more wear-resistant than an abraded surface of the same profilometer reading. Profilometers measure roughness height. Abrasive finishing processes remove metal by cutting or tearing it away, and while this usually lowers the roughness profile, it leaves sharp projections in the contact plane of the machined surface.
Burnishing displaces metal, rather than removing it.
Material in microscopic “peaks” on the machined surface is caused to cold flow into the “valleys,” creating a plateau-like profile in which sharpness is reduced or eliminated in the contact plane. A burnished surface is therefore smoother than an abraded surface with the same roughness height measurement. The burnished surface will last longer under working conditions in contact with a mating part.
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