If you have parts that need edge or surface finishing and would like to have FREE sample part processing and a quotation developed for finishing the parts please contact Dave Davidson at dryfinish@…
If you have parts that need edge or surface finishing and would like to have FREE sample part processing and a quotation developed for finishing the parts please contact Dave Davidson at email@example.com I can also be reached at 509.230.6821
Model HZ-60 Centrifugal Barrel Machine typically used for high energy processing for deburring, edge-contour, finishing and polishing metal and plastic parts from the aerospace, automotive, medical, dental, electronic, jewelry and other industries.
Some typical parts finished are shown in the application slide gallery shown below. [click on the image to enlarge it].
Centrifugal Super-Finishing of High Performance Automotive Components
Simiular processing on pistons…
Step 1 is a smoothing operation, Step 2 utilizes dry process finishing media to develop the final polished superfinish…
For more information contact Dave Davidson: http://en.gravatar.com/dryfinish
Mass media finishing techniques (barrel, vibratory, centrifugal and spindle finish) can be used to improve part performance and service life, and these processes can be tailored or modified to amplify this effect. Although the ability of these processes to drive down deburring and surface finishing costs when compared to manual procedures is well known and documented, their ability to dramatically effect part performance and service life are not.
For many decades there has been an awareness of cutting tool edge condition and tool surface finish and the effect it has on piece part quality and tool life. There have been many independent studies, tests, and implementations of edge conditioning methods to create extended life in turning, drilling, and milling cutter tooling – some published but most kept “secret” as a manufacturing advantage.
- For many decades there has been an awareness of cutting tool edge condition and tool surface finish and the effect it has on piece part quality and tool life. There have been many independent studies, tests, and implementations of edge conditioning methods to create extended life in turning, drilling, and milling cutter tooling – some published but most kept “secret” as a manufacturing advantage. — Jack Clark, Surface Analytics LLC and Colorado State University
The “Deburr/Finish Tech Group” of the SME has tasked itself to manage the project and use it’s member resource pool to provide tooling, applications, and the necessary documentation and reporting to objectively test cutting tool edge radius improvement on tool life and piece part consistency. This is a proposed outline on how to organize and conduct such a test. It is the intention of the participants to publish a document, possibly an SME Technical paper or article, at the conclusion of the study.
- To see an example of some superfinishing equipment being used for the research project see: https://www.youtube.com/watch?v=w5pyX9ix2Sw
GOALS: Confirm that edge and finish conditioning improves tooling life and potentially also improves performance values in tool speed, feed speed and substrate surface finish and helps prevent part surface finish deterioration from tool wear over extended periods of time.
Excerpted from SME Technical Paper MR79-569 by J. Bernard Hignett
[ed. note: Harperizer and Harperized are trade names that refer to a specific OEM’s brand of centrifugal barrel finishing equipment]
Metal fatigue is the most common cause of fracture in metal components. It is usually caused by numerous repeated applications of low stress—stress much lower than that needed for fracture in a single application. The higher the stress, however, the fewer applications are needed to cause failure. It follows that fatigue failure will be most cannon in components that are highly stressed and subject to repeated applications of stress in their functioning. A fatigue crack usually starts because the tensile component of stress at the surface of the material is too high. It is thus beneficial to impart compressive stress of components to oppose any tensile stress towhich the component may be subjected in service.
Edge and surface finishing improvement can reduce the risk of fatigue failure. Surface imperfections can act as stress raisers and removal of these will invariably improve performance of any highly stressed part. For critical components it is desirable to achieve very high surface finishes to facilitate inspection for stress raises. Removal of burrs and uniform radiusing of all sharp edges and corners will similarly improve performance.
As has already been discussed, the CBF process can simultaneously deburr, edge radius and surface finish an immense range of components. It can also impart very high compressive stresses uniformly to the parts while edge .land surface finishing so offering unique capability of improving the resistance to fatigue failure of many highly stressed parts. The capability to improve resistance to fatigue failure is demonstrated by the results of some tests made by a manufacturer of stainless steel coil springs which were taken from a standard production run, Half of the components had the conventional finishing process of barreling, followed by shot peening, and the other half were processed in a centrifugal barrel machine for 20 minutes. The springs were tested to failure by compressing them from 1.104″ length to .730″, corresponding to a stress change from 9 to about 50,000 psi. The results were that all springs finished by the conventional method failed at between 160,000 and 360,000 cycles. The springs that had been Harperized failed at between 360,000 and 520,000 cycles, an average performance improvement of 60%.
The tests indicated a benefit potentially greater than mere improvement of resistance to fatigue failure. It was noted that some of the parts that were processed in centrifugal barrel equipment had clearly visible surfac e defects or inclusions. Such defects were not visible in the parts that had been barreled and peened. It was the parts with the visible defects which were always those that failed below 400,000 cycles so that if in inspection department were instructed ot to accept parts with such defects, then performance of the springs put into service would be of consistently much higher quality.
Even more striking results were observed during a series of tests in another set of production springs of a somewhat different type. The springs which were not processed in CBF equipment all failed life tests before 600,000 cycles. None of the springs which were Harperized had failed at 800,000 cycles, the limit of the test.
Using CBF markedly to improve resistance to fatigue failure by a combination of edge and surface finishing, together with imparted very high compressive stresses, is cheaper than finishing by conventional means and then shot peening. There are opportunities to improve the ultimate resistance to fatigue failure of many parts, and, of prime importance, enable much better quality control by facilitating inspection. There is no longer need for components to be designed to allow a proportion of parts to fail prematurely due to surface defects. Of course, the technique has wide use for spring components, for instrument parts, for bearings and throughout the aerospace industry. There are also many opportunities to utilize improved and more consistent performance to design some of the cost out of many more mundane components within the metalworking industry, in particular, some automotive parts.
Below are some further examples of surface finishes that can be developed with Centrifugal Isotropic Finishing.
Vibratory Cleaning of Turbo-Chargers for Remanufacturing [Video]