Combining the benefits of two proven technologies creates a perfect low Ra surface finish that improves the resistance of scuffing of the mating components, uniformly retaining lubricant while optimizing excellent fatigue strength.
The combined process is especially applicable to high performance gears in the aerospace and motor sport industries as well as other precision engineered components that operate under high stress conditions. While it is well known that shot peening increases resistance to fatigue failure and provides other benefits, tests have shown that the uniform surface that a controlled shot peening process creates is a perfect condition for a subsequent super-polishing process that is conducive to high performance, low operating temperatures, and retention and uniform flow of an even layer of lubricant.
High performance motor sport components such as bearings, gears, camshafts, cam-followers etc. normally require very low Ra surface finishes, but polishing to an absolute “glass” like surface would not be acceptable as some lubricant retention is key to temperature control and prevention of wear, so lubricants are designed to control temperature, minimize wear and friction, as in an F1 engine, uniform distribution of the lubricant is vital, some would say it is the engines lifeblood as it protects critical components and prevents power loss caused by deprivation of contact surfaces, likewise, aerospace engine bearings and gears operate in extreme conditions where the same surface finishing lubrication criteria applies.
Many advances have been made in the development of lubricants to operate and perform in high stress and high temperature conditions. If the mating interface surfaces of the components have a low Ra with extremely fine pockets (dimples) that are uniform and consistent, the correct amount of lubricant will be retained and distributed, performance and life of the engine is increased, and scuffing is greatly reduced.
Typically, the surface of a high performance component before shot peening and super-polishing is inconsistent, as the peaks and the valleys vary in height and depth. Shot peening alone will not produce the required Ra surface, and vibratory finishing alone will not necessarily provide the stress relieving qualities of the shot peening process, and in order to truly uniformly reduce the deep valleys, the vibratory process time can be excessive.
When the parameters of the shot peening process are precisely controlled (shot size, shot type, blast velocity, media flow etc.) a surface condition is created that has uniform peaks and valleys. This means that before the components are treated in the vibratory super-polishing process, the surface finish is reasonably uniform but importantly the valleys are consistent in depth, which means that the micro pockets remaining after the super-polishing process are perfect for lubrication retention and flow distribution.
Both stages of the process will maintain any critical component geometry and dimensions. It is very important to add that both the shot peening and polishing stages must be precisely controlled, as conventional shot blasting and vibratory finishing processes will not produce the required surface and will result in excessive stock removal.
Depending on the material of the components to be finished and the surface finish required, either a paste type process or a chemically accelerated process is applied; both create an “Isotropic” surface. The geometry and the power of the vibratory finishing machine is also a key factor in achieving the desired finish.
The final surface finishing is always our first consideration. Before we proceed, there is a process of evaluation in place on how to best achieve the desired results. There are variety of finishes we can apply. Each process is different, every result can be customized to fit client specifications. From rough to lustre… contact Vibra Finish for your own processing.
Mass finishing processes can be configured as either batch systems, in which batches of workpieces are added, run, and removed before the next batch is run, or as continuous systems, in which the workpieces enter at one end and leave at the other end in the finished state. They may also be sequenced, which involves running the workpieces through multiple different mass finishing processes; usually, the finish becomes progressively finer. Due to the random action of the processes, mass finishing is as much an art as it is a science.
Mass finishing is a group of manufacturing processes that allow large quantities of parts to be simultaneously finished. The goal of this type of finishing is to burnish, deburr, clean, radius, de-flash, descale, remove rust, polish, brighten, surface harden, prepare parts for further finishing, or break off die cast runners. The two main types of mass finishing are tumble finishing, also known as barrel finishing, and vibratory finishing. Both involve the use of a cyclical action to create grinding contact between surfaces. Sometimes the workpieces are finished against each other; however, usually a finishing medium is used. Mass finishing can be performed dry or wet; wet processes have liquid lubricants, cleaners, or abrasives, while dry processes do not. Cycle times can be as short as 10 minutes for nonferrous workpieces or as long as 2 hours for hardened steel.
Deburring machines come in wet and dry varieties. Vibra offers both types of machinery and both methods of finishing processes. Dry machines may be less expensive, but they do require some kind of dust collector, either dry (basically a big vacuum cleaner) or wet (which forces all grinding debris into a wet tank to cool and capture the debris, reducing the risk of fire or explosion).
Dry machines work well for grinding certain parts of similar material, all carbon steel, for instance. But wet deburring machines are an absolute must when grinding different metals, such as aluminum, which can produce combustible dust. If combustible dust is left in a dry dust collection system when steel is run, the sparks created from the steel can ignite the remaining dust, causing a fire or explosion. A wet system, on the other hand, creates no metal dust and so usually does not present such hazards.
Wet machines typically have ancillary equipment, such as a filter and a drying unit. The filter separates the grinding debris from the coolant and recirculates the coolant to spray where the grinding is taking place. The drying unit can include squeegee rolls that push the coolant off of a deburred and grained part, as well as a blower that removes the remaining liquid.
Various abrasive media may be integrated into an automated deburring system. Most have at least one wide-belt abrasive that rotates on a drum, and many have additional barrel brushes that span the width of the work area, as shown in the configuration at the top. Several specialty abrasive heads, including rotating brushes and discs (bottom) also are available. The abrasive choice depends on application requirements.
In most applications, wet deburring machines can prolong the life of abrasive media. With the right coolant, abrasive media can last even longer. Using water-soluble coolants,usually 95 percent water mixed with 5 percent coolant chemical, may almost double abrasive life versus using water alone.
If you have:
Flat parts that stick together
Parts sensitive to water
Thin parts prone to bending
Send your sample parts to our processing lab for a free assessment.
Vibra offers a rust removal service for our customers. This process is similar to rust inhibiting, but derusting process removes only the rust from the part – all other exposed metal along with their tolerances will not be affected. Afterwards, all types of rust inhibitors are applied to the part for rust protection. The total derusting process uses no harsh acids and leaves no powder residues on the parts.
Once again, all shapes and sizes are accommodated, packaged to the customers’ specifications. All services are performed with quick turn around and utilizing environmentally friendly methods. We also provide both pick-up and/or delivery service.