As the name suggests, it is the pressing of surface peaks using rollers or balls. This pressing results in mirror-like surfaces. It is generally applied on bores and shafts. In the absence of heat treatment, it produces very successful results on all types of metals (aluminum, cast iron, steel, stainless steel, bronze and all similar metals are suitable).
It is applied after pre-processing such as turning and reaming. For application after cold drawing or forging, material removal is required first. The surface must have the roughness created by machining so it can be pressed. With internal tools, diameter adjustment can be made with 2.5 micron (0.0025 mm) precision.
Most importantly, the process time is very short — just a few seconds.
Roller burnishing makes pre-processed parts (turned, reamed, etc.) smooth while simultaneously sizing them. In production where precision surfaces are required, a perfect surface is achieved in seconds instead of honing, lapping or grinding.
Working Principle
The basis of roller burnishing is a ball following a specific path, transferring the force applied to it onto the metal surface. It occurs through the contact of balls with the pre-processed metal surface (turned, reamed, etc.) using a precision mechanism.
When looking at the micro surface profile of metals, we see roughness that we can call peaks and valleys. During the burnishing process, force is applied on top of the peaks causing the valleys to rise. As the ball contacts the workpiece, the metal's yield point is exceeded and plastic deformation occurs. In this zone, the metal is compressed by hundredths of a millimeter. After plastic deformation, the material recovers slightly elastically. Here, the ball makes its final contact with the metal, ensuring the surface becomes smooth and shiny.
Internal Roller Burnishing Video
Application Examples
Advantages of Roller Burnishing Technology
- Very smooth surfaces of Rz < 1 µm and below can be achieved.
- The desired dimension is easily and quickly achieved with this method.
- The process is completed in a single pass. Processing time is measured in seconds rather than minutes compared to other methods.
- The burnishing process polishes the surface while simultaneously hardening it. It makes the processed surface more durable and shiny.
- Leaves no chips, chip dust or residue, produces no noise, causes no environmental harm.
- Tools can be mounted and used on all universal and CNC machines.
- Tools are highly durable. They can be used for a long time without dimensional changes from wear.
Browse our roller burnishing tools →
Prepared by: Yamac Aksan