CNC Grinding

Different grinding processes are used in metal cutting, depending on the requirements of the workpiece and the desired precision. Internal cylindrical grinding is often used to machine the inner surfaces of cylindrical workpieces, such as precision bores.

The process enables maximum accuracy and surface quality. External cylindrical grinding, on the other hand, is used to machine external surfaces such as cylindrical shafts or bolts and is ideal for rotationally symmetrical components. Surface grinding is used to produce precisely flat surfaces, while profile grinding is used specifically for workpieces with complex profiles such as Gear wheels or worms.

Centerless Grinding is particularly efficient for the series production of small components, as workpieces can be machined without clamping. Each process has its own specific advantages, depending on the geometry, material and application of the workpiece.

Choosing the right grinding wheel is a decisive factor for the quality and efficiency of the grinding process. Grinding wheels differ in abrasives such as corundum, CBN or diamond, each of which is suitable for different materials. For example, diamond wheels are suitable for hard materials such as carbide or ceramic, while corundum is often used for steel.

The grit size also plays a role: fine grit sizes ensure smooth surfaces, while coarse grit sizes enable fast material removal. The hardness of the grinding wheel and the type of bond also influence how long the wheel lasts and how precisely it works when grinding metal. An unsuitable grinding wheel can lead to increased heat generation, tool wear or poor surface quality, which is why it must be selected carefully.

The surface quality during Grinding depends on several factors that must be coordinated with each other. One crucial point is the right choice of process parameters. The speed of the grinding wheel, the feed rate and the infeed must be selected so that they process the material gently and at the same time ensure a high level of accuracy.

The use of suitable coolants and lubricants helps to minimize heat generation and ensure uniform processing. Equally important is the conditioning of the grinding wheel. Regular dressing keeps the wheel clean and the cutting edges sharp. The stability of the machine also plays a key role.

Low-vibration machines and precise clamping technology prevent irregularities and improve the surface quality. With these measures, even demanding roughness values, such as Ra 0.1 µm, can be reliably achieved.

Various faults can occur during Grinding that affect the quality of the workpiece. One of the most common errors are cracks or burns in the material caused by excessive heat development. Using effective cooling lubricant and reducing the infeed helps here.

Another error is uneven surfaces, which are often caused by a worn or unclean grinding wheel. Regular dressing of the grinding wheel can prevent this. Dimensional deviations are often caused by thermal expansion of the workpiece or inaccuracies in the machine.

A stable machine base and monitoring of the process parameters can help here. Finally, vibration problems are a frequent cause of imprecise machining. These can be avoided with precise workpiece clamping and well-maintained machines. Such errors can be minimized through a systematic approach and careful process monitoring.

In metal cutting, there are materials that are particularly challenging to Grinding and require special approaches. Hard metals and technical ceramics are extremely hard and abrasive, which requires the use of diamond or CBN grinding wheels.

These materials also require low infeeds and high speeds to avoid damage. Titanium and superalloys are difficult to machine due to their poor thermal conductivity, as they tend to overheat. Optimized cooling strategies are essential here. Stainless steel, on the other hand, tends to work harden, which means that sharp grinding wheels and a controlled feed are necessary to avoid material flow. Aluminum presents a different challenge, as it can easily clog the grinding wheel.

Special coatings and the use of suitable cooling lubricants help to solve this problem. However, with the right combination of abrasives, machine parameters and process strategies, even these demanding materials can be machined with high precision.