The Use of PVD Coatings for Weight Reduction in Automotive Applications. Dr Iain J. Smith, Dr Ton Hurkmans and Dr André Hieke

Transcription

1 The Use of PVD Coatings for Weight Reduction in Automotive Applications Dr Iain J. Smith, Dr Ton Hurkmans and Dr André Hieke Lean Weight Vehicle Conference - 5 th and 6 th November 2003

2 Introduction Main Energy Loss in Engines is due to Weight and Friction: 40% of total energy loss is consumed by engine friction. 29% of loss is related to weight. slide number 2 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

3 The Role of Surface Engineering Surface engineering in general and plasma surface engineering in particular can play an important role in helping to achieve both objectives of enhancing the engine efficiency and of decreasing the vehicle weight A.M. Merlo Centro Ricerche Fiat slide number 3 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

4 How does Surface Modification Reduce Weight? Reducing friction forces in engines allows component weight to be designed out Enhancing the wear resistance of surfaces allows lighter materials to be employed e.g. replacement of steel piston valves with titanium alloys. slide number 4 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

5 Surface Modification by PVD (Physical Vapour Deposition) Deposition under partial vacuum conditions At least one of coating species is atomised from solid state Generally plasma assisted & capable of processing at relatively low temperature (150 o C) Allow deposition of metals, alloys, ceramics & non-conducting coatings to variety of temperature sensitive substrates Unprecedented control of interface and ability to tailor the coating characteristics slide number 5 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

6 PVD Process slide number 6 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

7 Advantages of PVD Coatings Highly wear resistant materials (HV <4000) Increased abrasive wear resistance Anti-scuffing / anti-galling High fretting resistance High pitting resistance Tribological properties Reduced C.O.F. Corrosion resistant materials Combine in bulk - and surface properties Almost no change in tolerances; thin films Environmentally friendly slide number 7 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

8 Benefits of PVD Within Applications Smaller and lighter designs Reduced energy consumption Increased power density Cheaper base materials Lifetime increase Reduced Emissions slide number 8 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

9 Properties of PVD Tribological Coatings Carbon based Nitrides Sulfides Me-C:H DLC a-c a-c/me CrN TiN MoS 2 MoS 2 /Me Technology PVD/PACVD PACVD PVD PVD PVD PVD PVD PVD Hardness [GPa] C.O.F Thickness [µm] Max. temp. [ C] Ind. experience slide number 9 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

10 Example PVD Tribological Coating a-c:h W-C:H Cr Substrate slide number 10 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

11 Cross Section by TEM slide number 11 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

12 Friction Considerations (Coatings (dry) vs. steel ) Sliding distance slide number 12 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

13 Tailored Properties slide number 13 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

14 Industrial Volume PVD Coatings Tribological Applications Heavy Duty Example: Truck Engine slide number 14 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

15 PVD Coatings in Automotive Applications Piston area: Piston (carbon based coatings under development) Top piston ring (thick CrN) Piston pin (W-DLC) Sliding bearing (AlSn) Connecting rod (CrN) Common rail: Fuel injection plungers (W- DLC) Transmission area: Gears (W-DLC & B 4 C) Camshaft area Rollers Bushings Tappets Cams Air Conditioner: High contact pressure (W- DLC) General Purpose: Roller Bearings slide number 15 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

16 Opportunities for Weight Reduction Automotive components Camshafts, crankshafts, pistons, piston rings, tappets / shims, gears, bearings, valves, plungers (diesel injection) Increasing wear resistance Decreasing friction Targets: - Reduce energy consumption Improve fuel efficiency Reduction of the CO 2 -emission - Power amplification (Car Racing) Increasing acceleration camshaft tappets valves piston piston rings piston pin crankshaft slide number 16 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

17 PD-Injection System (1,9 l TDI- Motor) Technical Data Engine power: 96 KW (130 PS) Injection pressure: 2050 bar Pressure power: N Advantages Increased efficiency (lower friction) Increased engine torque Reduce energy consumption Reduction of the CO 2 -emission Source: Volkswagen AG, Wolfsburg slide number 17 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

18 1-Liter-Car Car data One-cylinder diesel direct injection engine Displacement 298 ccm Power 8,5 PS / 6,2 kw Drag coefficient 0,16 Length 3,65 m, height 1,25 m Weight 260 kg (incl. 35 kg Mg) petrol consumption 0,89 liter per 100 km Source: Volkswagen AG, Wolfsburg slide number 18 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

19 Performance Automotive Applications slide number 19 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike

20 Summary: PVD as part of The Weight Reducing System slide number 20 Lean Weight Vehicle Conference 5 th -6 th November 2003 Smith, Hurkmans and Heike