Tool processing overview
Workpiece: tool, all kinds
Material: Carbide and HSS
Processing content: deburring, leveling, rounding
1) Deburring, smoothing, polishing purposes
1a) The shaving of the cutter
Carbide, HSS tools can be burred at the time of manufacture. If they are not removed before coating, once the tool is put into use, the burr will collapse. This will produce an uncoated bare spot. There will be faster wear and greatly shorten the life of the tool.
Figure: burr---after profile grinding; after coating; no coating--- burr peeling
Features:
- immediate dimensional accuracy of the product
- Reduce the possibility of tool chipping, because of the spurs without collapse
- Increased service life
- Improve the adhesion of the coating at the edge
1b) Flattening the surface
Surface quality impact
In principle, we believe that the flatter the surface, the better the chip removal. The result is a greatly reduced waste heat generation, which can achieve higher cutting speed. Moreover, the surface quality is improved, and the risk of seizing the material to be processed is also reduced. In addition, during the tapping and thread forming process, the maximum cutting force can be reduced by 40%.
Other utility
The rough surface and sharp shape will increase the notch under load and cause the hard material coating to collapse.
Because the roughness after coating is also improved, it is necessary to level the surface before coating.
OTEC has developed a process that rounds the rough spikes. This greatly improves the surface quality and reduces the notch.
Features:
- Reduce the formation of knife tumors
- Improve coating adhesion
- Improve chip removal performance, reduce knife size, increase life and cutting speed, and reduce temperature problems
1c) Rounding of the cutting edge
For stability, dimensional accuracy and high surface quality, the state of the tool edge is the most important indicator.
The lower left picture shows the incorrect cutting edge with a chipping after grinding and small parts before machining with OTEC equipment.
Cemented carbide is a brittle material, which is easy to cause cracking under high pressure, especially when cutting hard and tough materials, such as titanium alloy. Such large and small cracking defects can lead to the loss of control of rounding of the cutting edge.
Because of the loss of the coating at the chipping edge, the stability of the tool is greatly reduced, and the surface quality is significantly deteriorated due to the great deterioration of the cutting edge.
Tool tip after machining
The middle figure shows the edge of the cemented carbide milling cutter after machining with the OTEC DF-W model. The difference between the front and the back is very obvious.
Through this OTEC process, not only a uniform edge rounding can be achieved, but also a significantly improved surface quality.
Advantages of machining with OTEC's DF machine before tool coating
- Adapt the tool to the material to be machined by a targeted rounding of the cutting edge.
- Improve the stability of operation
- Reduce the tendency of chipping
- Maximum doubling of service life
- Optimization of surface quality
- Uniform cutting edge
- Guaranteed process reliability of cutting
- Maximum cutting edge stability for higher cutting speeds,
- No traces of processing (such as jitter marks when cutting aluminum)
- Dimensional accuracy, such as in step drilling, if not rounded, the size becomes smaller after chipping
The following recommended rounding dimensions are derived from practice and experimentation
- Aluminum 1-3 μm (machining time = 10-30 seconds)
- Steel 15-20 μm (machining time = 3-5 points)
- Titanium alloy up to 30 μm (machining time = 10-15 minutes)
2) Fixing the tool
The tool is fixed in a special fixture before machining, which ensures contactless machining and avoids damage.
Depending on the type, size and shape of the tool to be machined, there are different clamping methods.
Example of clamping method
Clamp with handle tool
(Drive type jig) Special jig for the blade
(drive type fixture)
Drive type tool holder
As long as the size of the workpiece is appropriate, the tool is machined in the driven tool holder
8 The chuck can be clamped up to 12mm in diameter, the maximum total diameter of the tool = 50mm, and can be used for up to 8 tools.
6 The chuck can be clipped up to 34mm in diameter, the maximum total diameter of the tool = 60mm, and can be used for up to 6 tools.
4 chucks can be clamped up to 40mm in diameter, the maximum total diameter of the tool = 80mm (DF 70), up to 4 tools
After the tool is clamped, it is driven by a special abrasive. The abrasive is selected according to the specific requirements.
The processing technology can choose different parameters, the abrasive used, the direction of rotation, the rotational speed, the processing time, the immersion depth, the size and shape of the workpiece, etc., determine the pros and cons of the process as a whole.
3. Parameters affected
3 a) Abrasives
Choosing the appropriate abrasive has a great influence on the processing, among which the particle size, hardness and density
As a special point, sanding or polishing additives (such as P1 polishing paste) can be added to the walnut shell particles, which determines the strength of the polishing and the state of the edges and faces of the workpiece after processing.
Tool processing, different combinations of abrasives can be used for the corresponding requirements
Walnut Shell Particles - Processing HSS tools such as H 1/400
- . Polishing, tiny deburring and edge rounding
- Different polishing strength depending on additives
HSC Particles - Processing HSS and Carbide Tools
- Deburring and edge rounding of the tool
- Flattening and removing drip of coated tool
- Flatness and polishing of carbide tools
- Carbide rounding up to 20μm
- Remove welding residue
- Strong toughness according to particle size
- Achieve high surface quality, such as Rz.0, 5 (previously Rz.2.5)
SIX Particles - Machining Carbide Tools
- Flattening and edge rounding of carbide tools
- Processing of the blade
- The polishing strength is strong
- Achieve high surface quality
3 b) Edge rounding of carbide tools depending on machining time and abrasive
3 c) direction of rotation
Targeted control of the machining with the corresponding direction of rotation
If a strong edge is required to be rounded, the direction of rotation is opposite to the cutting edge, ie clockwise to the right (top shank). If the best surface quality is required and the smallest edge is rounded, the direction of rotation follows the edge. Counterclockwise left
Right-handed (2) left-handed (4)
Reverse machining with the cutting edge (1). Processing with the back of the cutting edge (3).
Good flute processing, good chip flute processing
The main and secondary cutting edges are well-rounded, and the secondary cutting edge is well rounded.
3 d) speed
The rotational speed also has an effect on the processing force. The hardness, density and particle size of the abrasive used together determine the rotational speed of the relatively different polishing strength.
If the speed is too high, the tool may be loose, so that the chip flutes are not evenly processed or not in place. However, when the workpiece is elongated, the force generated at high speed may cause the cutter to rupture.
3 e) Processing time
Processing time is the most important parameter, from a few seconds to 20 minutes
3 f) Workpiece size
The size and shape of the tool have an effect on the machining process. The size and shape are fixed and
Können nicht verändert werden.
The larger the diameter of the workpiece, the higher the speed on the blade
If the speed and processing time are the same, the smaller diameter tool (1), the larger diameter (2), the smaller the stroke, so that the polishing is smaller
This difference can be balanced by the speed and processing time, ie high diameter with high speed (eg 30-40 U/min), large diameter low speed (20 U/min.).
3 g) tool shape
Entgraten
Werkstücke: Zerspanungswerkzeuge aller Art
Werkstoff: Hauptsächlich HSS
Bearbeitungsziel: Entfernen des Schleifgrates
4) Deburring of the tool
The burrs generated in the manufacture of HSS tools are much higher than those of cemented carbide tools. This mainly refers to HSS taps.
Most of the workpiece is a tap
The material is mainly HSS
Processing content to remove grinding burrs
Abrasive preferred HSC particles
Direction of rotation 0-20% right, 80-100% left
Processing time 2 – 10 minutes, depending on the burr
5) Rounded edge
Workpiece: All tools that require edge rounding
Material: All tool materials, mainly carbide
lProcessing content: Rounding of the main and auxiliary blades before direct use or coating
Abrasive: HSC particles, rounded to 0,02 mm
SIX particles, rounded to 0,05 mm
Direction of rotation: 100% right-handed
Processing time: 1 – 20 minutes depending on requirements
After processing
Advantages: Accurate and average edge rounding while flattening chip flutes. Improve appearance
Evaluation: More precise, uniform and simpler than other brands, only we can round and flat at the same time with precision and uniformity
Easy to use because the process incorporates the size and shape of the tool
Bring good adhesion to the coating
Improve operational stability
6) Leveling of tools with and without coating
All types of workpieces
Material HSS and cemented carbide
Flattening the flutes before and after processing the content coating; removing the drops from the coating
Abrasive HSC particles
The direction of rotation for a tool with a helix is ​​20% right-handed, 80% left-handed
Knives and blades without spirals are 50% right-handed; 50% left-handed
80% right-handed when 20° rounding is required at the same time; 20% left-handed
Processing time coated tool: maximum 3 minutes, 30 seconds of right-handed rotation, long right-handed time may damage the main and secondary cutting edge coating. Drops can be removed in 1-2 minutes
Uncoated tool: 5-30 minutes according to processing steps and surface requirements
Before the coating edge is processed (800 times magnification) After the coating edge is processed (800 times magnification)
Droplet before processing (2000x magnification) Droplet removal after processing (2000x magnification)
The situation of the drop before processing (magnification 2000 times) The situation of the drop after processing (as if 2000 times larger)
Advantages: Whether or not the rounding edge is required at the same time, the flute is flat and fast and simple
Rapid and positive removal of the droplets after coating
The unique shape of the workpiece has no effect on this process as it is incorporated into the process reference
Evaluation: Good coating adhesion
Appearance gloss is improved at the same time
Flat flutes reduce knife knobs
Up to double the cutting speed and lower the temperature
Improve tool life
Vent Pipe,Stainless Steel Pipe,Adjustable Bracket
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