Ceramic Applications in the Automotive Industry
Ceramic Applications in the Automotive Industry
Michael. J. Hoffmann
Institute for Applied Materials - Ceramics in Mechanical Engineering
S
E
KIT – University of the State of Baden-Württemberg and National Large-scale Research Center of the Helmholtz Association www.kit.edu CeramicsCeramics components components in in automotive automotive applications applications filter, catalyst carrier fuel injectors high pressure pump
electronic device
Functional Ceramics
spark andknocking glow sensor plugs, oxygen sensor, knocking sensor, parking distance control, PTC heaters, fuel injection systems
PTC heater
1 Institute for Applied Materials- Ceramics in Mechanical Engineering CeramicsCeramics components components in in automotive automotive applications applications filter, catalyst carrier fuel injectors high pressure pump
electronic device
Structural Ceramics pump componentsknocking sensor (sealings), brake discs, catalyst support, particulate filter,
PTC heater
2 Institute for Applied Materials- Ceramics in Mechanical Engineering ProjectionProjection of of Total Total Energy Energy Demand Demand and and Energy Energy Mix Mix
• Liquid fuels will still significantly contribute to up-coming energy demands • Combustion engines are necessary in the next decades • Individual transport: long range distance, trucks, hybrids
3 Institute for Applied Materials- Ceramics in Mechanical Engineering EuropeanEuropean Fuel-Economy Fuel-Economy Goal Goal up up to to 2025 2025
150 37,3 mpg 140 130 42 mpg 120 110 100 57,4 mpg US Goal: 100 g/km Emission [g/km]
2 90
CO 80 70 78,4 mpg 60 2010 2015 2020 2025 2030 Year Goal can only be obtained by more efficient combustion engines → Downsizing concept (smaller, but more efficient engines)
4 Institute for Applied Materials- Ceramics in Mechanical Engineering DownsizingDownsizing concept concept
Downsizing is based on the principle of a reduction in engine size in order to reduce consumption without affecting power.
Measures: - Reduction of number of cylinders - Supercharging (use compressed air) - Direct injection systems
Challenges and Needs: - Injection control system - High pressure fuel pump - High thermal and mechanical loading
Downsizing can reduce the CO2 emissions between 5% for diesel models and 40% for gasoline models by 2020. These engines should be able to remain dominant for a long time in the car market.
5 Institute for Applied Materials- Ceramics in Mechanical Engineering DownsizingDownsizing concept concept
Downsizing is already reality in the present US market
6 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
7 Institute for Applied Materials- Ceramics in Mechanical Engineering PiezoelectricPiezoelectric Driven Driven Common Common Rail Rail Fuel Fuel Injection Injection Technology Technology
high pressure pump fuel injector
electronic device
courtesy: Robert Bosch GmbH
Piezo technology increases efficiency and reduces emission → already used in Diesel systems, but with a high potential for gasoline systems
8 Institute for Applied Materials- Ceramics in Mechanical Engineering PiezoelectricPiezoelectric Driven Driven Common Common Rail Rail Fuel Fuel Injection Injection Technology Technology
metal parts ceramic parts
-40 %
Pfister et al. Cer. Trans. (2011)
High fuel injection pressure is needed to reduce droplet size (-40%), → decrease of fuel consumption and pollutant emissions (-80%)
9 Institute for Applied Materials- Ceramics in Mechanical Engineering FuelFuel evaporation evaporation in in combustion combustion chamber chamber
source: Spicher, KIT-IFKM
10 Institute for Applied Materials- Ceramics in Mechanical Engineering 3-Piston3-Piston High High Pressure Pressure Pump Pump for for Gasoline Gasoline Engines Engines
KIT / IFKM, Pfister, Spicher
Cam/sliding-shoe contact is tribological highly loaded due to an insufficient lubrication of petrol with increasing pressure → ceramic components can be a solution
11 Institute for Applied Materials- Ceramics in Mechanical Engineering FrictionFriction coefficient coefficient in in the the cam/sliding-shoe cam/sliding-shoe contact contact
SSiC / SSiC SiAlON / SiAlON
Pfister et al. Cer. Trans. (2011)
Silicon carbide and SiAlONs indicate a similar behaviour with a very low friction coefficients at a system pressure of 50 MPa
12 Institute for Applied Materials- Ceramics in Mechanical Engineering EffectEffect of of surface surface texturing texturing of of the the cam/sliding-shoe cam/sliding-shoe contact contact
-75 %
Pfister et al. Cer. Trans. (2011)
The texture significantly improves the performance of self-mated silicon carbide at low speed or low contact force
13 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
14 Institute for Applied Materials- Ceramics in Mechanical Engineering GasolineGasoline direct direct injection injection system system
Source: KIT / IFKM, Spicher
An ignitable mixture for low and high loads is only formed in a very narrow spatial zone
15 Institute for Applied Materials- Ceramics in Mechanical Engineering FutureFuture trends trends for for spark spark plugs plugs in in fuel-efficient fuel-efficient engines engines
Microstructure with a glassy phase and pores
4 µm
Challenges • Distance between electrodes will increase • Higher voltage will be applied → longer spark • Pressure increase in combustion chamber → higher thermal and mechanical loading • reduction in size
16 Institute for Applied Materials- Ceramics in Mechanical Engineering StrengthStrength distribution distribution and and typical typical failure failure mechanisms mechanisms ofof commerical commerical spark spark plugs plugs
compaction defects Manufacturer
Strength distribution reflects also the electric breakthrough behaviour → Most current commercial materials do not match the requirements
17 Institute for Applied Materials- Ceramics in Mechanical Engineering FutureFuture trends trends for for spark spark plugs plugs in in fuel-efficient fuel-efficient engines engines
Challenges: • smaller diameter → higher thermal and mechanical loading → strength must be increased by enhanced processing conditions • adjustable resistance • high voltage → increase in electrical breakthrough
18 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
19 Institute for Applied Materials- Ceramics in Mechanical Engineering MetalMetal Matrix Matrix Composites Composites for for Highly Highly Loaded Loaded Engine Engine Parts Parts
Engine part manufactured by pressure die casting of Al-based alloys
after German, 1994 Inhomogeneous cooling causes thermal stresses that can be minimized by a local reinforcement with ceramics (preform concept).
20 Institute for Applied Materials- Ceramics in Mechanical Engineering LocalLocal reinforcement reinforcement of of pressure pressure die-casted die-casted Al-MMCs Al-MMCs
local reinforcement (cermic preform)
21 Institute for Applied Materials- Ceramics in Mechanical Engineering PreparationPreparation of of Porous Porous Ceramic Ceramic Preforms Preforms
Pore filler concept Freeze casting Ceramic foams
40 µm 100 µm 250 µm
Porosity: up to 75% Porosity: 20-85% Porosity: 85-95% Pore size and shape Ice crystals form final cell size depends on depend on filler pores polymer foam
Mattern et al., JECS (2004). Different types of ceramic preforms can be manufactured by using powder technology processes.
22 Institute for Applied Materials- Ceramics in Mechanical Engineering PreparationPreparation of of freeze-casted freeze-casted Al-MMCs Al-MMCs
100 µm
ceramic wall
Ice lamella
Cooled plate
Waschkies et al., JACS (2009) 2 mm
S. Roy & A. Wanner, Compos. Sci. Technol. (2008)
23 Institute for Applied Materials- Ceramics in Mechanical Engineering EstimationEstimation of of failure failure probabili probabilityty for for different different perform perform types types
1E-9 foams . MPa] 2 1E-10 freeze casting
1E-11 Survival region . with pore fillers
1E-12 Failure region permeability strength [m strength permeability 1E-13 pressure 0,01squeeze 0,1 1 10 castingeffective melt velocity [m/s]casting Mattern et al., JECS (2004).
Freeze casted preforms can be used for pressure casting, while preforms with pore fillers and bottle neck pores will break
24 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
25 Institute for Applied Materials- Ceramics in Mechanical Engineering MechanismsMechanisms of of high high field field strain strain in in ferroelectric ferroelectric ceramics ceramics
Piezoelectric effect (intrinsic)
Strain behaviour dhkl dhkl E-Feld S
Domain switchung (extrinsic) E ∆L
E-Feld
→ High strain materials rely on both intrinsic and extrinsic effect
26 Institute for Applied Materials- Ceramics in Mechanical Engineering StrainStrain behaviour behaviour of of a a ferroe ferroelectriclectric ceramic ceramic at at 20 20 kV/cm kV/cm
20.000 Volt 0,20 P Z T -
0,16 1 cm
0,12
0,08 + High field strain [%] 20 µm strain at 20 kV/cm
0,04 80 Volt - 80 µm 0,00 0,0 0,5 1,0 1,5 2,0 2,5 + Electric field [kV/mm] 0,16 µm strain at 20 kV/cm
Typical strain of a donor-doped Pb(Zr,Ti)O3 ceramic (PZT): 0.15 - 0.2 % at 20-30 kV/cm → Multilayer device
27 Institute for Applied Materials- Ceramics in Mechanical Engineering PiezoelectricPiezoelectric Driven Driven Common Common Rail Rail Fuel Fuel Injection Injection Technology Technology
electronicPZT-layers
courtesy: Robert Bosch GmbH
termination → typical driving voltage: 100 V, total strain 20-30 µm internal electrodes (AgPd)
28 Institute for Applied Materials- Ceramics in Mechanical Engineering RequirementsRequirements for for piezoelectric piezoelectric act actuatorsuators for for fuel fuel injection injection systems systems
• cofiring with internal electrodes (multilayer device) • high strain • operating temperatures from -40 to 150 °C • small temperature dependence of strain • high reproducibility (mass production) •“lowcost“ • challenge: replacement of PZT by lead free ferroelectrics
29 Institute for Applied Materials- Ceramics in Mechanical Engineering Comparison of Pb(Zr,Ti)O and a lead-free ceramic Comparison of Pb(Zr,Ti)O33 and a lead-free ceramic
E = 2 kV / mmRB KNN‐PSU E = reference 2 kV / mmsamples 1000 600600 20 kV/cm LFL493 ( ‐ ref) ML172 ( ‐ 61 mu) 800 500500 ML503 ( ‐ 144 mu)
400 600 33% 400 pm/V
300 160% * (pm/V) 400 * (pm/V) 300 d33*, 33 33 d d 200 La-PZT 200 200 53/47 100 (Li,Sb)-doped KNN 53.5/46.5 100 0 0 0 50 100 150 0 50 100 150 0 Temperature (°C) Temperature (°C) 0 50 100 150 Lead-free ceramics show a lower strain for a similar electricTemperature, field °C strength and exhibit a much stronger temperature dependence of strain
30 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
31 Institute for Applied Materials- Ceramics in Mechanical Engineering HeatHeat deficiency deficiency for for car car heating heating systems systems with with efficient efficient engines engines
source: eberspächer catem, Germany
The increasing efficiency of fuel saving cars requires a supplementary heat system based on functional ceramics showing a positive temperature coefficient resistance (PTCR) effect.
32 Institute for Applied Materials- Ceramics in Mechanical Engineering PTC effect in donor-doped BaTiO -based ceamics PTC effect in donor-doped BaTiO33-based ceamics
(Bi K ) 250 0,5 0,5
7 /cm]
10 [°C]
Ω (Bi Na ) 200 0,5 0,5 C Pb 106 150 Ca
5 10 100
4 10 50 Zr TC
3 Curie Temperature T
Specific Resistance [ Specific Resistance 10 0 0 50 100 150 200 250 300 350 400 Temperature [°C] 0 5 10 15 20 25 30 35 x [mol %]
• PTC-effect is based on the temperature depended potential barrier at the grain
boundary Æ high electrical resistance above TC • The ferroelectric phase equals the charge of the potential barrier below TC Æ low electrical resistance
33 Institute for Applied Materials- Ceramics in Mechanical Engineering BaTiO -based PTC heating elements BaTiO33-based PTC heating elements
1 Vaporizer 2 Car Heater 3 PTC auxiliary heater
source: eberspächer catem, Germany
Highly efficient cars do not produce enough „waste energy“ for heating
34 Institute for Applied Materials- Ceramics in Mechanical Engineering PTC effect in donor-doped BaTiO -based ceamics PTC effect in donor-doped BaTiO33-based ceamics
Seat heater for convertibles
OEMs favour different local heating elements to reduce total energy consumption
35 Institute for Applied Materials- Ceramics in Mechanical Engineering OutlineOutline
• High pressure pump systems for gasoline engines
• Spark plugs
• Porous ceramics for local reinforcement of metal matrix composites
• Piezoelectric injection systems
• PTC heating elements
• General conclusions
36 Institute for Applied Materials- Ceramics in Mechanical Engineering RequirementsRequirements and and Challenges Challenges for for Materials Materials Research Research
Complexity of requirement profiles for the system
Structural Reliability Quality Properties Costs Functional Weight… Properties Composites Multifunctional Properties Multimaterial Composites Complexity in materials preparation Complexity in materials Powder Thermomechanical Technology Treatment
37 Institute for Applied Materials- Ceramics in Mechanical Engineering 37 RTC | 06/23/2007 | © 2007 Robert Bosch LLC and affiliates. All rights reserved. RequirementsRequirements and and Challenges Challenges for for Product Product Development Development
Return + Prototype
06 07 08 09 10 11 12 13 14 15 SOP Reduction of product Reduction of development time product life cycle - Support through modeling and simulation and better coordination Time
→ Reduction of product development time due to shorter product life cycles
38 Institute for Applied Materials- Ceramics in Mechanical Engineering ModelingModeling and and simulation simulation across across the the whole whole length length scale scale
length scale
10-10 -10-9 m10-7 -10-5 m10-2 -10-1 m
courtesy: P.F. Becher
Ab-initio calculations Phase field or vertex dynamic FE-methods for calculation MD- simulation simulation of coupled loading conditions → New materals → Microstrutural design → Design optimization
39 Institute for Applied Materials- Ceramics in Mechanical Engineering ConclusionConclusion
Fixed first idea
from the first idea to the product
Raw project Board project Product in the market Accepted products
Economically successful products
source: Kienbaum, Bullinger
40 Institute for Applied Materials- Ceramics in Mechanical Engineering