ECOROLL AG

Weidou Intelligent Technology specializes in supplying German ECOROLL AG tools. Please feel free to contact us for inquiries.

Introduction to the application principles of ECOROLL AG roller burnishing tools: ECOROLL AG roller burnishing tools are divided into roller polishing and deep rolling. Weidou Intelligent Technology will explain the application principles of ECOROLL AG roller polishing and deep rolling, as well as the similarities and differences between them.
Weidou Intelligent Technology looks forward to providing more assistance in the application of ECOROLL AG tools.

1, ECOROLL AG Basic principles of roller polishing

ECOROLL AG Material flow diagram

The main goal of ECOROLL AG roller polishing is to achieve high-quality smooth surfaces with a predetermined surface finish. One or more rollers or balls plastify and deform the surface layer of the workpiece. This process is used when the goal is to achieve high-quality surface finish or when predefined surface finish cannot be achieved by machining. Please refer to VDI guideline 2032, which explains the differences between roller polishing and rolling.

At the contact point, the polishing force generates contact stress in the edge region of the material. If this stress exceeds the yield strength of the material, the material near the surface begins to flow. As the ball or roller moves across the workpiece surface, the peaks on the surface are pressed almost vertically into the surface, and then the material flows into the valleys between the peaks (Figure 1). The resulting smooth surface is not because the peaks are bent into the surface (a widely held but incorrect assumption), but because material flow eliminates surface roughness.

Almost all methods used to manufacture high-quality surfaces can be replaced by roller polishing (such as finishing, grinding (superfinishing, lapping, etc.), wear, honing, polishing, friction). This proven method offers significant technical and economic advantages for surfaces in the roughness range Rz <10μm.

Polished surfaces are structurally distinct and can be characterized as follows:

Low roughness (Rz <1μm/ Ra <0.1μm) or defined roughness.
Rounded surface profile.
High surface bearing ratio.
Reduced friction and wear.
Increased hardness through cold working.
The benefits are:

ECOROLL AG tools offer short cycle times and eliminate setup and auxiliary processing time.
Suitable for conventional or CNC controlled machines.
Processing is completed in a single setup.
No material removal, no waste generated.
Easy to reproduce.
Low lubricant requirements.
Low noise emission.
Long tool life.
Tool wear causes no dimensional change.

2 ECOROLL AG Basic principles of deep rolling

ECOROLL AG Figure 1: Compressive residual stress in the edge zone

ECOROLL AG Figure 2: Material flow during cold forming

ECOROLL AG Figure 3: Percentage of cold forming

ECOROLL AG Figure 4: Smoothing

Deep rolling is similar to roller burnishing when the rollers deform and positively influence the properties of the component's edge zone. However, this is a **process that combines

the generation of compressive stresses,
cold working in the edge zone of the material,
and smoothing of the component surface, thereby removing micro-notches.
This combination can increase fatigue strength by up to five times, thus significantly extending the service life of components. Deep rolling is particularly recommended for components subjected to dynamic stresses during operation, which may otherwise suffer from material fatigue damage.

Compared to alternatives such as shot peening, deep rolling incurs lower costs and investment and is applicable to almost any metal surface. Deep rolling tools can be used on existing customer machine tools (conventional and CNC controlled) and can be seamlessly integrated into the process chain. Workpieces can be deep rolled directly after machining in a single setup. Setup and transport costs can be eliminated. The process can be applied to various components to increase fatigue strength or to enable lightweight design solutions.

Deep rolling can replace all mechanical (e.g., shot peening), thermal (e.g., laser hardening), and thermochemical (e.g., nitriding) processes used to increase the fatigue strength of workpieces. As we are committed to providing needs-oriented solutions, please contact us for detailed information and recommendations.

3 ECOROLL AG Similarities and differences between burnishing and deep rolling

ECOROLL AG Figure 5: Plunge rolling

ECOROLL AG Figure 6: Rolling with feed motion

ECOROLL AG Figure 7: 3-D rolling of free-form surfaces

The technologies developed by ECOROLL AG can be applied across a wide range of industries, including engineering, medical technology, automotive industry, aircraft and aerospace, energy industry, and anywhere metal components must be improved to enhance fatigue strength and service life or to promote better functionality. Roller burnishing and deep rolling tools are compatible with almost all machine tools (e.g., conventional and CNC controlled lathes, drilling machines, milling machines, and other machining centers). Therefore, workpieces can be burnished or deep rolled directly after machining in a single setup. For certain cases involving complex machine tools, separate deep rolling machines can be provided for parallel use during machining.

Different process motions are possible for both processes. *The simple variant is plunging (Figure 1). Here, the roller or ball is pressed against the surface of the workpiece in an axial position. The burnishing force accumulates over several rotations and remains constant during subsequent rotations. At the end of the process, the burnishing force is reduced during the *final rotation. This motion is necessary to prevent stress gradients in the surface layer of the component, which could lead to premature failure. This kinematics is primarily used in deep rolling to eliminate notch effects, for example, on wavy components.

The second variant, feeding, is used for easy and rapid machining of, for example, cylindrical surfaces (Figure 2).

Tools with hydrostatically loaded balls can perform burnishing and deep rolling even on *complex profiles and free-form surfaces (Figure 3). Their unique tracking system allows the burnishing ball to follow the workpiece contour while maintaining a constant burnishing force. For safety-critical components where constant machining quality is indispensable, only force-controlled tools can be used for roller burnishing and deep rolling.

Furthermore, hydrostatic tools can process materials with hardness up to 65 HRC (Rockwell hardness C). Even so, smoothing, cold working, and the induction of residual compressive stresses in the surface layer of the component are achieved.

The main difference between roller burnishing and deep rolling lies in the objective. When the goal is to improve surface finish (i.e., achieve a specific roughness), roller burnishing is the method of choice. The primary purpose of deep rolling is to increase the fatigue strength of components. This improvement in service life is mainly based on strain hardening and the induction of residual compressive stresses in the edge zone. However, simultaneous improvement of other surface qualities is certainly advantageous but not critical in deep rolling.

Furthermore, quality management differs between the two processes. For roller burnishing, simple measurement of coating quality is required. If predefined parameters are not achieved, the burnishing process can be repeated.

When deep rolling is involved, more complex procedures are required, such as durability testing or residual stress measurement, which result in component destruction. For quality assurance during deep rolling, it is necessary to reliably reproduce predefined and approved parameters. Especially where safety-related components are involved, process monitoring and recording during operation are indispensable.

Weidou Intelligent Technology specializes in supplying German ECOROLL AG tools. Please feel free to contact us for inquiries.