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엔진부품을 위한 카본계 내마모 윤활코팅. 2006. 5. 30. KIST- 현대자동차 협력 포럼 KIST 미래기술연구본부 이 광 렬. Contents. Brief Introduction to Diamond-like Carbon Coatings Applications of DLC to Automobile Parts DLC Research at KIST. Hard disk. Heart valve. What is DLC ?. Amorphous Solid Carbon Film
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엔진부품을 위한 카본계 내마모 윤활코팅 2006. 5. 30. KIST-현대자동차 협력 포럼 KIST 미래기술연구본부 이 광 렬
Contents • Brief Introduction to Diamond-like Carbon Coatings • Applications of DLC to Automobile Parts • DLC Research at KIST
Hard disk Heart valve What is DLC ? • Amorphous Solid Carbon Film • Mixture of sp1, sp2 and sp3 Hybridized Bonds • High Content of Hydrogen (20-60%) • Synonyms • Diamond-like Carbon • (Hydrogenated) amorphous carbon (a-C:H) • i-Carbon • Tetrahedral Amorphous Carbon
Bond Structure of Carbon 1S2 2S22P2
2-D Analogy of Structure a-C:H ta-C
경질코팅층의 내마모 윤활특성 마모도 마찰계수. DLC WC TiN CrN TiCN 2.0 1.6 1.2 0.8 0.4 (상대비교치) 0.2 0.4 0.6 0.8 1.0 Against steel ball, 50% RH, RT (Source : Nanotech Co. Ltd)
CD/DVD Mold Form Die VCR Head Drum Spacer Tool Hard Disk & Slider Wrist Pin Digital VCR Tape Razor Blade Applications of DLC
CarbofilmTM by Sorin Biomedica, Inc. Applications of DLC
1000 Dense Hydro- Carbon Dense Carbon 100 Impact Energy (eV) Polymer Like Carbon 10 Amorphous Carbon (sp2) 1 Plasma Polymers Carbon Source Hydrocarbon Source Deposition Methods Ion Source Energy Cold Substrate
Ion Energy Distribution PACVD
Development of Diesel Engines • Diesel engines are designed with continuously increasing power densities since the introduction of HP-fuel injection systems (1993). • Power and torque of diesel engines increased at a much higher rate than gasoline engines. • Meetenvironmental laws and cost reduction requirements. Momentum development for typical 2 liter Petrol and Diesel engines over 35 years. (Source : Dr. Strondl @ Hauzer)
Driving Force : Economy and Environment • Reduction of Energy Consumption • Reduction of friction • Reduction of Emission • Higher pressure fuel injection • Predictable wear of piston ring • Cost Reduction • Reduction of parts numbere.g. sliding bearing instead of needle bearing coated piston pin coated tappet • Wear Protection • Higher load per surface area
camshaft tappets valves piston piston rings crankshaft Friction Loss in Engine (Source : Dr. Strondl @ Hauzer, 2005)
Available Coatings at Present (Source : ICMCTF 2005 / 2006)
Coating Technology for Automobile Engines (Source : Dr. Strondl @ Hauzer, 2005)
Penetration Fraction of PVD (2006) • Diesel Pump 100% since 1994 • Crankshaft Bearing 100% since 1987 • Piston Ring 10% since 1993 • Valve train (Tappet) 2% since 2001 • Piston Pin 1% since 2002 • Gear < 1% since 2000
Optimized to the application for minimum wear and power consumption Composition Multilayer structure Microstructure Demands in Automobile Applications • Low wear of Coated Part • Suppress abrasive wear • Suppress adhesive wear • Suppress fatigue wear • Low Wear on Counterpart • Low Coefficient of Friction
Nanocomposite / Multilayer 5nm 5nm W-DLC by Hybrid Ion Plating (KIST) CrC/W-DLC Multilayer (Hauzer)
Fuel Injection System Part: Diesel fuel injector and plunger Coating: a-C:H, W-C:H with metallic buffer Coating thickness >1 μm Benefit Wear resistance, preventing seizure 2000~3000bar Figure from Robert Bosch GmbH
Unit Injection System (1.9TDI) • Technical Data • Engine power: 96 KW (130 PS) • Injection pressure: 2050 bar • Pressure power: 14.000 N • Advantages • Increased efficiency (lower friction) • Increased engine torque • Reduce energy consumption • Reduction of the CO2-emission Source: Volkswagen AG, Wolfsburg
Valve Train (Source : Dr. Strondl @ Hauzer)
Piston Ring - Sliding contact - Abrasive wear (also liner to be protected) - Temperature load Coating 200 µm hard Cr (galvanic) 30-40 µm CrN (PVD Arc) ~10 µm DLC (PACVD) / Me-DLC (PVD) (Source : KIST & DHI 1996)
DLC Application by Nissan 日産自動車,水素フリーDLCコーティングによる摩擦低減技術を開発 日經 BP 2006/03/15 21:15 Compatibility with special lubricant of different additives (m = 0.07) 연말 실용화 목표
Gears Full oil film lubrication DLC has not shown a beneficial influence. Boundary lubrication(stopping/starting, severe load, temporary loss of lubricant) DLC coatings can significantly reduce wear. Maximum load carrying capacity of gears can be increased by 10-40%. Coated spur gear
Coating Technology for Automobile Engines (Source : Dr. Strondl @ Hauzer, 2005)
DLC Research @ KIST • Synthesis and Application of DLC Films • Control of structure and properties of DLC films • Modification of DLC films by third element addition • Nanoscale structure manipulation for novel functions • Tribo-chemical Aspect of DLC Films • Mechanical Properties of Thin DLC Films • Application technologies • Adhesion improvement • Coating layer optimization • Production process development http://diamond.kist.re.kr/DLC
CD/DVD Mold Form Die VCR Head Drum Spacer Tool Hard Disk & Slider Wrist Pin Digital VCR Tape Razor Blade Applications of DLC
Technology Transfer to Industry J&L Tech Co. Ltd Daewoo Electronics Co.
Application to Top Ring Required Properties of Top Ring • Anti-scuffing • Wear Resistance • Low Friction Coefficient • Chemical Stability • Self Lubrication • Low Cost Schematics of Diesel Engine
Deposition Method • 250KHz PACVD using CH4 at 200 mTorr • Cylinder Coating Technology (analogy to VCR Head Drums) • Buffer Layer Design for Optimum Adhesion ~10mm Thick Films
sliding direction piston ring cylinder liner (boron cast iron) Reciprocal Tribometer (Plint 77)
Anti-scuffing Property of Piston Rings Test condition : load :200N, marginal lub. condition 250 200 150 Time to failure(hour) 100 50 0 Cr WS2-1 WA2-2 GN PVD DLC
Result of Dynamo Test (900h) Hard Cr Coated Ring DLC coated Ring Before Test Before Test After Test After test
Hard Cr Coated Piston Ring DLC/Cr Coated Piston Ring 6.5mm 100mm Before Test Before Test 5.3mm After Test After Test
Adhesion In most cases, film adhesion is more important than the mechanical properties. Environmental Effects Compatibility with new lubricants Adhesion degradation in aqueous environment Tribochemical Reaction for Fundamentals In-situ observation of the contact surfaces Third element effect Multilayer effect Market Penetration Based on the advanced technology Issues in Carbon Base Coatings