In order to achieve better cutting quality and the longest possible tool life, we need to check the inserts after processing, summarize the causes of different forms of insert wear and find solutions, which are the basis for successful milling.

 

 

Flank wear 1

 

Rapid wear leads to poor surface quality or out of tolerance.

 

 

the reason

Cutting speed is too high

Insufficient wear resistance

Feed fz is too low

 

solution

Reduce cutting speed (vc)

Choose a material with higher wear resistance

Increase feed (fz)

 

Flank wear 2

 

Excessive wear leads to short tool life.

 

 

 

 

the reason

vibration

Chip recut

Burrs are formed on parts

Poor surface quality

Generate heat

 

solution

Increase feed (fz)

Down milling

Use compressed air to effectively remove chips

Check recommended cutting parameters

 

Flank wear 3

 

Uneven wear leads to damage to sharp corners.

 

 

 

 

 

 

 

the reason

Tool runout

vibration

Short tool life

Poor surface quality

loud noise

Radial force is too high

 

solution

Reduce the amount of runout to be less than 0.02 mm

Check chuck and jacket

Minimize tool extension

Use fewer teeth for cutting

Choose a larger tool diameter

For solid carbide end mills and interchangeable head milling cutters, choose a geometry with a larger helix angle (gp ≥45°)

Divide the axial depth of cut (ap) into multiple passes

Reduce feed (fz)

Reduce cutting speed (vc)

High-speed machining requires shallow passes

Improve tool and workpiece clamping

 

Crescent crater wear

 

Excessive wear leads to reduced cutting edge strength. Damaged cutting edges result in poor surface quality.

 

 

 

 

 

 

 

the reason

Diffusion wear caused by excessive cutting temperature of the rake face

 

solution

Choose alumina coating material

Use positive rake angle blade geometry

Reduce the speed to get a lower temperature, then reduce the feed

 

Plastic deformation

Plastic deformation of the cutting edge, sag, or recessed flank, resulting in poor chip control, poor surface quality, and blade breakage.

 

 

 

 

the reason

Cutting temperature and pressure are too high

 

solution

Choose a material with higher wear resistance (higher hardness)

Reduce cutting speed (vc)

Reduce feed (fz)

 

Chipping 1

 

The part where the cutting edge is not involved in cutting is damaged by chip hammering. Damage to the front and support surfaces of the blade, resulting in poor surface texture and excessive wear on the flank surface.

 

 

 

 

 

 

 

the reason

Chips are squeezed by the cutting edge

 

solution

Choose a grade with higher toughness

Choose inserts with stronger cutting edges

Increase cutting speed vc

Select positive rake angle geometry

Reduce feed at the beginning of cutting

Improve stability

 

Chipping 2

 

A small part of the cutting edge is broken (crushed) resulting in poor surface quality and excessive wear on the flank.

 

 

 

 

 

 

 

the reason

Material toughness is too low

The blade geometry is too weak

Buildup

 

solution

Choose a grade with higher toughness

Choose an insert with a stronger geometry

Increase the cutting speed vc, or choose a positive rake geometry

Reduce feed at the beginning of cutting

 

Groove wear

 

Groove wear leads to poor surface quality and the risk of cutting edge fracture.

 

 

the reason

Work hardened material

Epidermis and oxide skin

 

solution

Reduce cutting speed (vc)

Choose a grade with higher toughness

Use a stronger geometry

Use a cutting angle closer to 45°

Use round blades to ensure best results

Use variable AP technology to delay wear

 

Hot crack

 

Due to temperature changes, small cracks perpendicular to the cutting edge cause chipping and poor surface quality

 

 

the reason

Intermittent processing

Changing cutting fluid supply

 

solution

Choose a material with higher toughness and better thermal shock resistance

Cutting fluid should be used in sufficient amount or not at all

 

Built-up tumor 1

 

The built-up edge leads to poor surface quality and causes the cutting edge to chip when it falls off.

 

 

the reason

The temperature in the cutting area is too low

Materials with very high viscosity, such as mild steel, stainless steel and aluminum

 

solution

Increase cutting speed vc

Change to a more suitable blade geometry

 

Built-up tumor 2

The workpiece material is welded to the cutting edge.

 

 

the reason

Low cutting speed vc

Low feed fz

Negative rake angle cutting geometry

Poor surface quality

 

solution

Increase cutting speed vc

Increase feed (fz)

Select positive rake angle geometry

Use oil mist or cutting fluid