Overview of DLC Coated Tools for Aluminum Alloy Dry Machining

This document provides a comprehensive technical overview of DLC (Diamond Like Carbon) coated drills and end mills optimized for high-performance dry and wet machining of aluminum alloys. DLC coatings offer significant advantages including low friction, high hardness (3500-4000 HV), excellent wear resistance, and prevention of aluminum adhesion, enabling advanced machining capabilities.

1. DLC Coating Characteristics and Benefits

• Low friction coefficient: Minimizes tool wear and enhances chip flow.
• High hardness: DLC hardness between 3500-4000 HV improves wear resistance.
• Anti-adhesion: Prevents aluminum chip sticking due to high lubricity.
• Smooth surface finish: Enhances tool life and machining quality.
• Proven technology: First practical coating applied globally on cutting tools for aluminum alloys.

2. Tool Types and Selection

• DLC Drills: Micro drills, regular drills, and HSS drills.
• DLC End Mills: Sharp corner, long sharp corner, radius, slot long shank, and ball mills.
• DLC-Coated Inserts: For milling applications.

Selection charts and VAN codes facilitate easy identification of tool types and sizes.

3. Performance and Application Data

• Dry and wet machining: DLC tools enable dry machining previously unachievable with conventional tools and support wet machining at cutting speeds up to 200 m/min.
• Chip control: Smaller chip curl radius improves evacuation.
• Non-step drilling: Patented groove design allows drilling up to 5 times the drill diameter (5D) depth without step feed.
• High precision: Milling shank design ensures machining accuracy.
• Extended tool life: DLC drills outperform uncoated carbide drills in both dry and wet conditions, demonstrated on aluminum alloys ADC12 and A5052.
• Superior surface finish: DLC-milled surfaces show significantly lower roughness (Ry and Ra) even in dry machining.

4. Cutting Conditions and Recommendations

• Typical drill cutting speed: 100 m/min; feed rate ~0.08 mm/rev.
• End mills: Cutting speeds up to 572 m/min; feed rates up to 0.15 mm/tooth depending on tool and material.
• Dry machining feasible with air blow or MQL; wet machining supported with water-soluble fluids.
• Depth of cut and machining depth vary by tool and material; detailed charts provided.

5. Tool Dimensions and Stock Availability

Comprehensive dimension tables cover drill diameters (0.5 mm to 20+ mm), flute lengths, overall lengths, shank diameters, and tolerances. End mills available in multiple diameters, flute lengths, corner radii, and shank sizes. Stock status indicated for standard and semi-standard items.

6. Specialized DLC End Mills

• Sharp Corner and Long Sharp Corner Mills: Designed for precise corner machining with high rigidity.
• Radius Mills: Optimized for smooth surface finish and wear resistance.
• Slot Long Shank Mills: Enable deep pocket milling up to 4D depth with high efficiency and precision.
• Ball Mills: DLC-coated ball end mills for 3D machining with optimized chip evacuation and surface quality.

7. Comparative Performance Highlights

• DLC-coated tools outperform uncoated carbide tools in tool life, wear resistance, and surface finish.
• Dry machining with DLC tools matches or exceeds wet machining results with conventional tools.
• Reduced adhesion and wear lead to fewer tool failures and longer machining runs.

8. Milling Conditions and Tool Specifications

Detailed milling parameters for aluminum alloy A5052 using DLC-coated carbide ball end mills and DLC-HSS mills include cutting speeds (e.g., 471 m/min), feed rates (e.g., 3000 mm/min), and depths of cut (0.2-0.5 mm). Both dry (air blow) and wet (water-soluble coolant) milling are supported. Stocked tool sizes with tolerances enable precise tool selection.

9. DLC-Coated Inserts and Tool Features

DLC-coated inserts provide superior anti-adhesion, excellent surface finish, and extended tool life. The carbide base combined with DLC coating enhances wear resistance, suitable for dry milling aluminum alloys. Features include low friction, stable chip discharge, and sharp cutting edges with high rake angles.

10. Recommended Cutting Conditions

Cutting speeds and feed rates are specified for various tool diameters and aluminum alloys (ADC12, A5052). Adjustments are recommended based on machining conditions: wet milling feed rates increase by 1.25x; groove milling requires spindle speed reduction to 70% and feed rate reduction to 25% of standard values.

11. Drilling Tools and Conditions

DLC-HSS drills offer stable machining and longer life than uncoated carbide drills, featuring special flute designs for efficient chip evacuation and reduced adhesion. Drilling parameters include diameters, hole depths (up to 5D for dry drilling), cutting speeds (~100 m/min), and feed rates (~0.15 mm/rev). Wet coolant is recommended for deeper holes.

12. Performance and Wear Characteristics

Comparative data show DLC-HSS mills outperform uncoated carbide mills in flank, boundary, and corner wear resistance. DLC coatings contribute to stable cutting and improved surface finish, even in dry machining.

13. Stock and Dimensional Tables

Extensive tables list stocked sizes for drills and mills, including diameters, flute lengths, overall lengths, and shank diameters. Symbols indicate stock availability or made-to-order status. Tolerances ensure precision in tool selection.

14. Machining Recommendations and Limitations

• Use maximum spindle speed on low-speed machines, adjusting feed rate proportionally.
• Dry drilling limited to hole depths of 5x drill diameter; deeper holes require wet or MQL processes.
• Wet milling allows increased feed rates for efficiency.
• Groove milling requires reduced spindle speed and feed to maintain tool life and surface quality.
• Long tools require feed rate reduction to 50% of standard values.

15. Work Materials and Applicable Alloys

Machining parameters cover aluminum alloys including pure aluminum (1017, 1070), aluminum castings (AC, ADC), Si and Mg-Si alloys (4032, 6061), Mg alloy (5052), Zn-Mg alloys (7075), and copper alloys (C1100).

16. Summary of Milling and Drilling Cutting Conditions

General Instructions and Adjustments

• Operate at machine max spindle speed if recommended speed is unattainable; adjust feed rate accordingly.
• Wet milling feed rates increased by 1.25x.
• Groove milling requires spindle speed reduction to 70% and feed rate reduction to 25% of standard values.
• Dry milling (air blow) requires spindle speed and feed rate reduction to 70%; dry slotting reduces feed rate to 20%.
• Adjust cutting conditions if vibration or noise occurs.
• Do not exceed drilling depth greater than end mill diameter.

Milling Conditions

Cutting parameters for DLC-coated mills (sharp corner, radius, long shank slot) for aluminum and copper alloys are provided. Mill diameters range from 3 mm to 20 mm. Depths of cut and feed rates are expressed as multiples of mill diameter.

Work Materials Covered

• Pure Aluminum (1070)
• Copper Alloys (C1100)
• Silicon-based Aluminum Alloys (4032, 6061)
• Magnesium-based Aluminum Alloys (5052)
• Copper-Zinc-Magnesium Alloys (2014, 7075)
• Aluminum Alloy Castings (AC2A, AC8C, ADC12)

Cutting Conditions Tables

Tables specify spindle speeds and feed rates for various materials and mill diameters under standard, side milling, grooving, and high-speed conditions.

Drilling Conditions

• Parameters for DLC-mill ball and DLC-HSS drills (1 mm to 20 mm diameter) are provided.
• Recommended spindle speeds and feed rates vary by alloy.
• Step feed recommended for deep holes (>3x diameter) or horizontal machines with sufficient coolant.
• Reduce speed and feed by 20% for rolled or forged surfaces.
• Dry drilling requires 70% reduction in speed and feed.

Special Recommendations and Safety Precautions

• Use DLC mills especially for cast aluminum alloys (AC4, ADC12).
• Do not use tools with excessive wear or chipping.
• Securely clamp tools and workpieces.
• Beware of fire hazards from hot chips or sparks; ensure guards and remove flammable materials.
• Avoid contact with cutting edges and rotating tools.
• Cutting conditions may change without notice due to improvements.
• Unauthorized reproduction of catalog content is prohibited.

Key Parameters and Formulas

• Depth of cut (aa) and radial depth of cut (ar) expressed as multiples of mill diameter (D), e.g., aa=1.2D, ar=0.2D for side milling.
• Feed rates and spindle speeds adjusted by machining type, material, and machine capability.
• Dry machining and groove milling require significant speed and feed reductions.

Summary of Adjustment Factors

17. Contact Information and Distribution Centers

Contact details for regional offices and distribution centers in Japan are provided to facilitate communication and logistics:

• East Osaka Office: Phone (06)6748-1955; Address: 2-73-14 Honjo Nishi, Higashi Osaka City, Nachi Osaka Building, Postal Code 578-8522.
• Chugoku-Shikoku Branch: Phone (086)244-0002, Fax (086)243-4346; Address: 2-2-30 Nishifurumatsu, Okayama City, Postal Code 700-0927.
• Hiroshima Sales Department: Phone (082)832-5111, Fax (082)832-5114; Address: 8-25-10 Nishihara, Asaminami Ward, Hiroshima City, Postal Code 731-0113.
• Kyushu Branch: Phone (092)441-2505, Fax (092)471-6600; Address: 1-10-30 Sanno, Hakata Ward, Fukuoka City, Postal Code 812-0015.
• East Japan Distribution Center: Phone (03)3692-6421, Fax (03)3692-6439; Address: 2-19-3 Higashi Shinkoiwa, Katsushika Ward, Tokyo, Postal Code 124-0023.
• Central Japan Distribution Center: Phone (052)682-9060, Fax (052)682-9080; Address: 2-20 Jinnocho, Atsuta Ward, Nagoya City, Postal Code 456-0068.
• West Japan Distribution Center: Phone (06)6744-9775, Fax (06)6744-9771; Address: 2-107 Honjo Naka, Higashi Osaka City, Postal Code 578-0957.

Summary: This document thoroughly details DLC-coated tools for aluminum alloy machining, emphasizing their superior wear resistance, anti-adhesion properties, and enhanced surface finish. It provides extensive specifications, performance data, cutting condition guidelines, and safety recommendations for both dry and wet machining. The inclusion of stocked tool sizes, tolerance data, and contact information supports optimized tool selection and operational efficiency.