Tool adhesion occurs when the cutting tool sticks to the workpiece material during CNC lathe operations. This can lead to material buildup on the tool, affecting machining quality and efficiency. To address this issue, it is essential to understand the properties of the material and the causes of adhesion to provide proper solutions.

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Aluminum and Aluminum Alloys

Aluminum-based materials improve physical and mechanical properties by adding other metallic elements.

• Pure aluminum: high ductility, low hardness.

• Aluminum-magnesium alloys: similar melting point as aluminum, higher ductility.

• Aluminum-zinc alloys: zinc melts at ~419°C, lower than aluminum.

• Aluminum-silicon alloys: silicon exists as hard, brittle particles that fracture easily during cutting.

Aluminum alloys have a relatively low melting point (~660°C). During machining, contact temperatures can reach 400°C. Though below the melting point, this is sufficient to cause tool adhesion. High ductility (10%-30% elongation) and plasticity increase the risk of built-up edge formation.

Effective Solutions:

• Tool Material: Use carbide tools.

• Tool Coating: Diamond or TiN (Titanium Nitride) coated tools.

• Cutting Parameters: Speed 100–300 m/min, feed 0.2–0.5 mm/tooth.

• Coolant: High-efficiency coolant designed for aluminum alloys.

• Cutting Oil: Sulfur-, chlorine-, or phosphorus-containing oils.

• Tool Geometry: Edge radius 0.01–0.02 mm; slight edge honing (0.02–0.03 mm).

• Technical Tip: Check tool sharpness every 30–60 minutes; recommend high-speed cutting.

• Coolant Injection: High-pressure coolant ensures full coverage of the cutting zone.

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Copper and Copper Alloys

• Pure copper: very ductile, relatively soft.

• Brass (Cu-Zn alloy): zinc melts at ~419°C, softens, and tends to adhere to tools.

• Bronze (Cu-Sn alloy): wear-resistant but prone to tool adhesion at high temperatures.

• Aluminum bronze: high hardness but generates high cutting temperatures causing tool adhesion.

Effective Solutions:

• Tool Material: WC-Co carbide, 0.4–0.6 µm grain size.

• Tool Coating: TiAlN or SiN for heat resistance and reduced adhesion.

• Cutting Parameters: Speed 50–200 m/min, feed 0.1–0.3 mm/tooth.

• Coolant: High-efficiency coolant like Castrol Syntilo 9954 or Blaser Blasocut BC25.

• Cutting Oil: Sulfur- and chlorine-based oils such as Castrol Alusol R.

• Tool Geometry: Edge radius 0.02–0.03 mm, slight honing 0.03–0.04 mm.

• Technical Tip: Check sharpness every 20–40 minutes; re-sharpen as needed.

• Coolant Injection: High-pressure injection to reduce temperature and friction.

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Stainless Steel

• Austenitic stainless steel: high toughness, ductility, work hardens easily.

• Martensitic stainless steel: low thermal conductivity, hard to dissipate heat, prone to adhesion.

• Duplex stainless steel: combines austenitic and ferritic properties, high strength, corrosion-resistant.

Effective Solutions:

• Tool Material: High-hardness, wear-resistant carbide tools.

• Tool Coating: TiAlN or TiSiN coatings for heat resistance and adhesion reduction.

• Cutting Parameters: Speed 50–150 m/min, feed 0.05–0.2 mm/tooth.

• Coolant: High-efficiency stainless steel coolant.

• Cutting Oil: Sulfur- and chlorine-containing oils.

• Tool Geometry: Edge radius 0.01–0.02 mm, keep cutting edge sharp.

• Technical Tip: Check sharpness every 20–40 minutes; adopt high-speed cutting where possible.

• Coolant Injection: High-pressure coolant ensures full coverage.

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Low-Carbon Steel

Low-carbon steels (C < 0.25%) have good toughness and ductility.

Effective Solutions:

• Tool Material: HSS or carbide tools.

• Tool Coating: TiN or AlTiN to improve wear resistance and reduce adhesion.

• Cutting Parameters: Speed 80–150 m/min, feed 0.1–0.3 mm/tooth.

• Coolant: Suitable for general steel.

• Cutting Oil: Sulfur- and chlorine-based oils.

• Tool Geometry: Edge radius 0.01–0.02 mm, smooth cutting edge.

• Technical Tip: Check sharpness every 20–40 minutes.

• Coolant Injection: High-pressure coolant ensures complete coverage.

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Carbon Steel (Low to High)

• Low-carbon steel (AISI 1018): C < 0.25%, high ductility.

• Medium-carbon steel (AISI 1045): C 0.25–0.60%, tends to form built-up edge.

• High-carbon steel (AISI 1095): C > 0.60%, hard, prone to adhesion at high temperature.

Effective Solutions:

• Tool Material: Fine-grain WC (0.2–0.4 µm).

• Tool Coating: TiN, AlTiN, or TiSiN.

• Cutting Parameters: Speed 80–180 m/min, feed 0.1–0.25 mm/tooth.

• Coolant: Suitable for low/medium/high carbon steels.

• Cutting Oil: High-pressure additive oils.

• Tool Geometry: Edge radius 0.01–0.03 mm; smooth edges.

• Technical Tip: Check sharpness every 20–40 minutes; use proper cutting fluids.

• Coolant Injection: High-pressure coolant for complete coverage.

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Titanium and Titanium Alloys

• Pure titanium: low thermal conductivity, high strength, prone to adhesion.

• Ti-Al alloys: high strength and corrosion resistance, generates high temperatures.

• Ti-Mo alloys: excellent mechanical and heat resistance, poor thermal conductivity.

Effective Solutions:

• Tool Material: Ultrafine-grain carbide (<0.5 µm).

• Tool Coating: AlTiN or TiSiN for heat resistance and reduced adhesion.

• Cutting Parameters: Speed 30–90 m/min, feed 0.1–0.3 mm/tooth.

• Coolant: Efficient coolant suitable for titanium alloys.

• Cutting Oil: High-pressure additive oils.

• Tool Geometry: Edge radius 0.02–0.04 mm; sharp, smooth edge.

• Technical Tip: Check sharpness every 20–30 minutes; use high-speed cutting when possible.

• Coolant Injection: High-pressure injection to reduce temperature and friction.