Material properties/surface properties
Strength
- Strength, in N/mm = resistance with which the material opposes an influence of force; the force can cause a plastic deformation, which actually occurs and is desired with roller burnishing.The strength is, for example, determined in the tensile test. The plastic deformation of the material sections increases their strength.
Hardness
- Hardness = mechanical resistance with which the material opposes a penetrating body.Measuring method: Rockwell, Vickers, Brinell The measuring methods differ in their geometry and evaluation process.
The increase in the surface hardness with roller burnishing is a positive effect of the process.
Material wear
- Material wearWearing of the surface
The abrasive wear is the weight loss (surface removal) of a material surface through grinding, rolling, striking and scratching loading.
In the process, the softer partner of a material pair is subject to wear.
Only minor abrasive wearing can take place on roller-burnished, and therefore extremely smooth surfaces, as the contact area ratio of the surface is extremely high.
Material loading
- Material loading/material breakageHow can the loadability of a workpiece be determined?
With static loading, the loadability of the workpiece up to the breaking point can be determined from the
- material values (strength graph) and
- the loading case.
- Fmax = strength x area.
With dynamic loading, the loading limit is considerably lower than with static loading (see the Wöhler curve at the right).
The failure usually begins with a diameter transition, as an increase in the tensile stress occurs at these points.
