During the processing of end mills, due to the physical and chemical properties of the material, the workpiece material sometimes adheres to the surface of the end mill, commonly known as “sticking”. This will lead to increased surface roughness, reduced dimensional accuracy, accelerated cutting tool wear, and even tool breakage, seriously affecting processing quality and efficiency.
Aluminum and Aluminum Alloy Adhesive Materials
Aluminum and aluminum alloys refer to materials with excellent physical and mechanical properties made from aluminum by adding other metal elements. Aluminum is the third most abundant element in the world and the most abundant recyclable metal. It has the characteristics of low density, high strength, good corrosion resistance, good machinability, and good conductivity, making it widely used in aerospace, automobile, construction, electronics and other fields.
Causes of Sticking of Aluminum and Aluminum Alloy
The melting point of aluminum alloy is about 660°C, and the temperature of the cutting zone during end milling can reach about 400°C. Although it is lower than the melting point, it is enough to soften the aluminum alloy and adhere to the surface of the tool.
Aluminum alloy has high ductility (elongation 10%-30%) and plasticity. During the cutting process, due to the plastic deformation of aluminum alloy, the chips are easily squeezed by the tool to the contact area between the tool and the workpiece, forming a built-up edge. The built-up edge will increase the friction between the tool and the workpiece, further aggravating the sticking phenomenon.
Sticky Materials
- Pure aluminum: has high ductility and low hardness, and is very easy to stick to the tool.
- Aluminum-magnesium alloy: The melting point of magnesium is the same as that of aluminum, but it has high ductility and is very easy to stick to the tool.
- Aluminum-zinc alloy: The melting point of zinc is about 419°C, which is lower than the melting point of aluminum, and is very easy to stick to the tool.
- Aluminum-silicon alloy: Silicon exists in the form of hard and brittle silicon particles, which are easy to fall off during cutting and are very easy to stick to the tool.
End Mill Processing Suggestions
- Tool material: Use carbide end mills, such as WC-Co carbide, with a particle size of 0.2-0.4 microns.
- Tool coating: Tools with diamond coating or titanium nitride coating are preferred.
- Cutting parameters: Cutting speed 100-300 m/min, feed rate 0.2-0.5 mm/tooth.
- Coolant selection: Use high-efficiency coolant suitable for aluminum alloy processing.
- Cutting oil selection: Use cutting oil containing sulfur, chlorine or phosphorus.
- Tool geometry: The edge radius should be controlled at 0.01-0.02 mm, and slight passivation can be performed. The edge passivation radius is about 0.02-0.03 mm.
- Technical advice: Check the sharpness of the tool every 30-60 minutes of cutting, and try to use high-speed cutting.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area.
Stainless Steel Sticky Materials
Stainless steel refers to a steel alloy containing chromium (generally at least 10.5%), which has excellent corrosion resistance and mechanical properties.
Reasons for Stainless Steel Sticking to the Tool
Stainless steel is prone to sticking to the tool because of its high strength, high toughness and low thermal conductivity. During cutting, the high temperature in the contact area between the tool and the workpiece can easily reach 300-600°C, causing the material to adhere to the tool.
Stainless steel has a strong tendency to work hardening, and it is easy to produce a work hardening layer during the cutting process, which increases the difficulty of cutting and causes the sticking phenomenon to become more serious.
Stainless Steel Sticky Materials
- Austenitic stainless steel (such as 304, 316): has high toughness and high ductility, strong tendency to work hardening, and is easy to stick to the tool during cutting.
- Martensitic stainless steel (such as 410, 420): Its low thermal conductivity makes it difficult for heat to dissipate quickly during cutting, and the temperature in the contact area between the tool and the workpiece increases, which is easy to stick to the tool.
- Duplex stainless steel (such as 2205): It has the characteristics of both austenitic and ferritic stainless steels, high strength and good corrosion resistance, but it is easy to stick to the tool during cutting.
End Mill Processing Suggestions
- End mill tool material: Use high-hardness and wear-resistant cemented carbide tools, such as ultra-fine-grain cemented carbide (grain size is 0.2-0.4 microns).
- End mill tool coating: Choose tools with titanium aluminum nitride (TiAlN) coating or titanium silicon nitride (TiSiN) coating to improve heat resistance and reduce adhesion.
- Cutting parameters: Cutting speed 50-150 m/min, feed 0.05-0.2 mm/tooth, maintain moderate cutting speed and feed to reduce heat accumulation and work hardening.
- Coolant selection: Choose high-efficiency coolant suitable for stainless steel processing.
- Cutting oil selection: Choose cutting oil containing sulfur and chlorine.
- Tool geometry: The cutting edge radius should be controlled at 0.01-0.02 mm to ensure the sharpness of the tool and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical advice: Check the sharpness of the tool every 20-40 minutes of cutting to maintain the sharpness of the tool; try to use high-speed cutting technology.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area and reduces cutting temperature and friction.
Titanium and Titanium Alloys Stick Material
Titanium and titanium alloys refer to materials with high strength, low density and excellent corrosion resistance made by adding other metal elements based on titanium.
Reasons for Titanium and Titanium Alloys Stick to the Tool
Titanium and its alloys are prone to stick to the tool because of their low thermal conductivity. High temperatures are easily concentrated in the contact area of the workpiece, which can be as high as 800°C, causing the material to soften and adhere to the tool.
The high chemical activity of titanium alloys, especially at high temperatures, is easy to react with tool materials to form metal compounds, further increasing the risk of sticking to the tool.
Titanium and Titanium Alloys Stick to the Tool
- Pure titanium: low thermal conductivity, high strength, easy to generate high temperature during cutting, resulting in sticking to the tool.
- Titanium aluminum alloy: has high strength and good corrosion resistance, but is prone to high temperature and chemical reactions during cutting, resulting in sticking to the tool.
- Titanium-molybdenum alloy: has excellent mechanical properties and heat resistance, but low thermal conductivity, and is prone to sticking to the tool during cutting.
End Mill Processing Suggestions
- End mill tool materials: Use ultra-fine particle carbide tools (particle size is less than 0.5 microns), such as cobalt-containing carbide (WC-Co) tools.
- End mill tool coating: Choose tools with aluminum titanium nitride (AlTiN) or titanium silicon nitride (TiSiN) coating to improve heat resistance and reduce adhesion.
- Cutting parameters: cutting speed 30-90 m/min, feed rate 0.1-0.3 mm/tooth, keep low cutting speed and moderate feed rate to reduce heat accumulation.
- Coolant selection: Use high-efficiency coolant suitable for titanium alloy processing.
- Cutting oil selection: Use cutting oil with high extreme pressure additives.
- Tool geometry: The edge radius should be controlled at 0.02-0.04 mm to ensure the sharpness of the tool and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical suggestions: Check the sharpness of the tool every 20-30 minutes of cutting to maintain the sharpness of the tool; try to use high-speed cutting technology.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area and reduce cutting temperature and friction.
Copper and Copper Alloy Sticky Materials
Copper and its alloys refer to materials with excellent physical and mechanical properties made from copper by adding other metal elements.
Causes of Sticking of Copper and Copper Alloys
Copper and its alloys are prone to sticking because of their relatively low melting point (the melting point of copper is about 1085°C). During cutting, the high temperature in the contact area between the tool and the workpiece can easily reach 300-600°C, which is lower than the melting point of copper, but is enough to cause sticking.
Copper alloys have high ductility and plasticity, and are prone to forming built-up edges during cutting, further increasing the risk of sticking.
Materials for Sticking Copper and Copper Alloys
- Pure copper: has extremely high ductility and low hardness, and is very easy to stick.
- Brass (copper-zinc alloy): The melting point of zinc is about 419°C, and it is easy to soften and adhere to the tool during cutting.
- Bronze (copper-tin alloy): has high wear resistance, but is also prone to sticking when cutting at high temperatures.
- Aluminum bronze: Copper alloy containing aluminum, although it has high hardness, is prone to high temperatures during cutting, resulting in sticking.
End Mill Processing Suggestions
- End mill tool material: Use carbide tools, such as WC-Co carbide, with a particle size of 0.4-0.6 microns.
- End mill tool coating: Choose tools with titanium aluminum nitride (TiAlN) coating or silicon nitride (SiN) coating to improve heat resistance and anti-adhesion.
- Cutting parameters: Cutting speed 50-200 m/min, feed 0.1-0.3 mm/tooth.
- Coolant selection: Use high-efficiency coolant suitable for copper alloy processing.
- Cutting oil selection: Use cutting oil containing sulfur and chlorine.
- Tool geometry: The edge radius should be controlled at 0.02-0.03 mm, and slight passivation can be performed. The edge passivation radius is about 0.03-0.04 mm.
- Technical suggestions: Check the sharpness of the tool every 20-40 minutes of cutting, and sharpen it as needed; try to use high-efficiency cutting technology.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area and reduce cutting temperature and friction.
Magnesium and Magnesium Alloy Sticky Materials
Magnesium and its alloys refer to lightweight materials made of magnesium by adding other metal elements, which have excellent specific strength and specific stiffness.
Reasons for Sticking of Magnesium and Magnesium Alloys
Magnesium and its alloys are prone to sticking to the tool because of their relatively low melting point (the melting point of magnesium is about 650°C). During cutting, the high temperature in the contact area between the tool and the workpiece can easily reach 200-400°C, causing the material to soften and adhere to the tool.
The high chemical activity of magnesium alloys, especially at high temperatures, is easy to react with tool materials to form built-up edge, further increasing the risk of sticking.
Material for Sticking of Magnesium and Magnesium Alloys
- Pure magnesium: The melting point is about 650°C, with high ductility and low hardness, and it is easy to stick to the tool during cutting.
- Magnesium-aluminum alloy: The strength is improved by adding aluminum, but the melting point is still low, and sticking to the tool is easy to occur during cutting.
- Magnesium-zinc alloy: It has high hardness and corrosion resistance, but it is easy to produce chemical reactions during cutting, resulting in sticking to the tool.
- Magnesium-manganese alloy: has good mechanical properties and heat resistance, but has low thermal conductivity during cutting and is prone to sticking.
End Mill Processing Recommendations
- End mill tool material: Use high-speed steel (HSS) tools or carbide tools to ensure that the tools have good heat resistance and wear resistance.
- Milling tool coating: Choose tools with titanium aluminum nitride (AlTiN) or silicon nitride (SiN) coating to improve heat resistance and reduce adhesion.
- Cutting parameters: Cutting speed 200-500 m/min, feed 0.1-0.3 mm/tooth, maintain high cutting speed and moderate feed to reduce heat accumulation.
- Coolant selection: Use efficient coolant suitable for magnesium alloy processing.
- Cutting oil selection: Use cutting oil containing sulfur and chlorine to reduce friction and adhesion.
- Tool geometry: The edge radius should be controlled at 0.01-0.02 mm to ensure that the tool is sharp and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical advice: Check the sharpness of the tool every 20-40 minutes of cutting to maintain the sharpness of the tool; try to use high-speed cutting technology.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area and reduces cutting temperature and friction.
Soft Steel Sticky Materials
Soft steel refers to steel with low carbon content (usually less than 0.25%), good toughness and ductility.
Causes of Soft Steel Sticking
Soft steel is prone to sticking because of its high ductility and low hardness, which is easy to produce plastic deformation during cutting, causing the material to stick to the tool.
Soft steel is prone to forming built-up edges during cutting, which increase the friction and temperature of the tool, further aggravating the sticking phenomenon.
Soft Steel Sticking Materials
- Low carbon steel (such as AISI 1018): low carbon content, high ductility and toughness, easy to stick during cutting.
- Soft low alloy steel: contains a small amount of alloying elements, although the strength is improved, it is still easy to stick.
End Mill Processing Recommendations
- Milling Cutter Material: Use high-speed steel (HSS) tools or carbide tools to ensure that the tools have good wear resistance.
- Milling Cutter Coating: Choose tools with titanium nitride (TiN) or aluminum titanium nitride (AlTiN) coatings to improve wear resistance and reduce adhesion.
- Cutting parameters: cutting speed 80-150 m/min, feed 0.1-0.3 mm/tooth, maintain moderate cutting speed and feed to reduce heat accumulation.
- Coolant selection: Use high-efficiency coolant suitable for soft steel processing.
- Cutting oil selection: Use cutting oil containing sulfur and chlorine to reduce friction and adhesion.
- Tool geometry: The edge radius should be controlled at 0.01-0.02 mm to ensure the sharpness of the tool and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical advice: Check the sharpness of the tool every 20-40 minutes of cutting to maintain the sharpness of the tool; try to use high-speed cutting technology.
- Cutting fluid injection: Use high-pressure injection cutting fluid to ensure that the coolant fully covers the cutting area and reduces cutting temperature and friction.
Low Carbon Steel and Carbon Steel Sticky Materials
Low carbon steel and carbon steel refer to steels with low and high carbon contents, respectively, and have good strength and toughness.
Reasons for Low Carbon Steel and Carbon Steel Sticky
Low carbon steel and carbon steel are prone to sticking because they have high ductility and plasticity, and are prone to plastic deformation during cutting, causing the material to stick to the tool.
Medium carbon steel and high carbon steel are more likely to form built-up edges during cutting, which increase the friction and temperature of the tool, further aggravating the sticking phenomenon.
Low Carbon Steel and Carbon Steel Sticky Materials
- Low carbon steel (such as AISI 1018): The carbon content is usually less than 0.25%, with high ductility and toughness, and it is easy to stick to the tool during cutting.
- Medium carbon steel (such as AISI 1045): The carbon content is 0.25%-0.60%, and it is easy to form built-up edges during cutting, resulting in sticking.
- High carbon steel (such as AISI 1095): The carbon content is usually greater than 0.60%, with high hardness, but high cutting temperatures can cause sticking.
End Mill Processing Suggestions
- Milling cutter tool materials: Use carbide tools, especially fine-grained carbide (grain size 0.2-0.4 microns) to improve wear resistance.
- Milling cutter tool coating: Choose tools with titanium nitride (TiN), aluminum titanium nitride (AlTiN) or titanium silicon nitride (TiSiN) coating to improve heat resistance and reduce adhesion.
- Cutting parameters: Cutting speed 80-180 m/min, feed rate 0.1-0.25 mm/tooth, reduce heat accumulation and work hardening.
- Coolant selection: Use high-efficiency coolant suitable for mild steel and carbon steel processing.
- Cutting oil selection: Use cutting oil with high extreme pressure additives to reduce friction and adhesion.
- Tool geometry: The edge radius should be controlled at 0.01-0.03 mm to ensure the sharpness of the tool and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical advice: Check the sharpness of the tool every 20-40 minutes of cutting to keep the tool sharp; for high carbon steel, use appropriate cutting fluid to reduce the processing temperature.
- Cutting fluid injection: Use high-pressure cutting fluid injection to ensure that the coolant fully covers the cutting area to reduce cutting temperature and friction.
High Temperature Alloy Sticky Materials
High temperature alloy refers to alloy materials with excellent mechanical properties and oxidation and corrosion resistance in high temperature environment, mainly nickel-based alloys, cobalt-based alloys and iron-based alloys.
Reasons for High Temperature Alloy Sticking
High temperature alloys are prone to sticking because of their high hardness and high toughness. The temperature in the contact area can be as high as 1000°C, causing material adhesion.
High temperature alloys are prone to work hardening during cutting, which increases the difficulty of cutting, resulting in increased tool wear and more serious sticking.
High Temperature Alloy Sticking Materials
- Nickel-based high temperature alloys: have excellent high temperature strength and oxidation resistance, but high temperature during cutting causes serious sticking.
- Cobalt-based high temperature alloys: have excellent thermal corrosion resistance, but are easy to soften and stick during high temperature cutting.
- Iron-based high temperature alloys: have good high temperature strength and heat resistance, but are prone to work hardening and sticking during cutting.
End Mill Processing Suggestions
- Cutting tool materials: Use polycrystalline diamond (PCD) tools or cubic boron nitride (CBN) tools to improve wear resistance and anti-adhesion.
- Cutting tool coating: Choose tools with titanium aluminum nitride (AlTiN) or titanium silicon nitride (TiSiN) coating to improve heat resistance and reduce adhesion.
- Cutting parameters: cutting speed 20-60 m/min, feed 0.05-0.2 mm/tooth, keep low cutting speed and moderate feed to reduce heat accumulation and work hardening.
- Coolant selection: Choose high-efficiency coolant suitable for high-temperature alloy processing.
- Cutting oil selection: Choose cutting oil with high extreme pressure additives.
- Tool geometry: The edge radius should be controlled at 0.02-0.05 mm to ensure the sharpness of the tool and reduce cutting resistance. The cutting edge should be kept smooth to reduce material adhesion.
- Technical advice: Check the sharpness of the tool every 10-20 minutes of cutting to maintain the sharpness of the tool; try to use high-speed cutting technology.
- Cutting fluid injection: Use high-pressure jet cutting fluid to ensure that the coolant fully covers the cutting area and reduces cutting temperature and friction.
