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Materials
For DE
PROJECTS
Materials
for Advanced Reciprocating Engine Systems (ARES)
 Advanced
reciprocating
engines will run at higher pressures and higher temperatures,
and will be required to produce fewer polluting emissions. These
demands require that engine materials, and pollution regulating
equipment be developed.
Projects
Development of Corrosion-Resistant Spark Plugs
-Dr. H.-T. Lin
Advanced
Materials for Exhaust Components for Reciprocating Engines
- Dr. Philip Maziasz
Development
of Catalytically Selective Electrodes for NOx and Ammonia Sensors
– Dr. T. Armstrong
Accomplishments
Champion and ORNL Develop Erosion-Resistant Spark Plugs (FY 05/06)
Posters
Advanced Reciprocating Engine Systems (ARES) (PDF 2.65MB)
Improved ARES Ignition Systems (PDF 2.65MB)
Development of Corrosion-Resistant Spark Plugs
Contact: Dr. H.-T. Lin
Oak Ridge National Laboratory
Bethel Valley Rd
PO Box 2008
Oak Ridge, TN 37831-6068
(865) 576-8857
linh@ornl.gov
Ignition systems have been identified by natural gas reciprocating engine manufacturers as a key technology to achieve cost/performance/emission goals for lean and stoichiometric engines. Spark plug electrode wear may greatly limit the advancement of natural gas reciprocating engines technologies. Current spark plug lifetimes are only ~2-6 months while desired spark plug lifetimes of at least 1 year is desired. As engine combustion conditions beome more lean to reduce emissions, spark plug reliability and lifetime performance will become even more critical.
In FY2005, ORNL, Catapillar, and Cummins collaborated to identify materials-related phenomena that play a role in the electrode wear, including oxidation and cracking of electrode materials. This insight provides an important basis to select and/or design new electrode alloy materials. A collaboration was established with Federal Mogul (Champion®) to manufacture spark plugs utilizing new electrode alloys. The initial plan calls for the fabrication and evaluation of three sets of plugs. The first set uses alternative electrode alloys but does not use precious metal inserts; theywill be used to establish baseline behavior. The second set of plugs will incorporate a control precious metal insert, and the third set will utilize a developmental high performance ORNL replacement alloy for the precious metal insert. Work in FY 2006 will be devoted to engine testing of these developmental plugs, followed by detailed spectral analysis and post-test microstructural characterization to assess performance and wear behavior. The characterization of the engine tested developmental ORNL alloys, along with continued analysis of select field tested commercial spark plugs, will be used to refine understanding of the electrode wear mechanisms and provide further basis for optimization of alternative alloys to achieve lifetime durability goals.
The latest and archived Quarterly Progress Reports are available in the on-line material in the Reports section.
Recent Publications: Refer to the Bibliography section for more publications
L. R. Walker, H. T. Lin, I. Levina, M. P. Brady,, and J. Lykowski, “SEM and EPMA Analysis of Spark Plug Electrode Erosion," pp. 1614-15 in Proceeding of Microscopy and Microanalysis 2005,“ July 31-August 4, 2005, Honolulu, Hawaii. (PDF 659KB)
H. T. Lin, M. P. Brady, R. K. Richards, and D. M. Layton “Characterization of Erosion and Failure Processes of Spark Plugs After Field Service in Natural Gas Engines,” Wear, Vol. 259/7-12 pp. 1063-1067 (2005). (PDF 446KB)
R. K. Roger, D. M. Layton, H. T. Lin, and M. P. Brady, “Characterization of Erosion Mechanisms for Natural Gas Engine Spark Plugs,” ICEF2004-875 published at Proceedings of Internal Combustion Engine Division of ASME 2004 Fall Technical Conference, October 24-27, 2004, Long Beach, CA. (PDF 2.7MB)
Presentations: Refer to the Presentations section for additional presentations
L. R. Walker, H. T. Lin, I. Levina, M. P. Brady, and J. Lykowski, “SEM and EPMA Analysis of Spark Plug Electrode Erosion,” presented at Microscopy and Microanalysis 2005,“ July 31-August 4, 2005, Honolulu, Hawaii. (PDF 3.1 MB)
H. T. Lin, M. P. Brady, R. K. Richards, and D. M. Layton “Characterization of Erosion and Failure Processes of Spark Plugs After Field Service in Natural Gas Engines,” April 24-28, 2005, San Diego, CA. (PDF 4.5MB)
R.K. Richards, T.J. Theiss, H. T. Lin, and M. P. Brady, “Characterization of Erosion Processes of Spark Plugs After Field Service in Natural Gas Engine Spark Plugs,” presented at Internal Combustion Engine Division of ASME 2004 Fall Technical Conference, October 24-27, 2004, Long Beach, CA. (PDF 5.5MB)
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The latest and archived Quarterly Progress Reports are available in the on-line material in the Reports section.
Advanced
Materials for Exhaust Components for Reciprocating Engines
Contact:
Dr. Philip Maziasz
Oak Ridge National Laboratory
Bethel Valley Rd
PO Box 2008
Oak Ridge, TN 37831-6116
(865) 574-5082
maziaszpj@ornl.gov
Advanced natural gas reciprocating engines (ARES) will run at higher pressures and higher temperatures than current engines. These conditions shorten component life, increase the likelihood of failure, and cause more wear problems. In FY 2005, ORNL completed the initial phase of a broad, systems-approach effort with Waukesha Engine Dresser (WED) to define temperature/performance limits for in-cylinder materials. This task focused mainly the high-temperature physical metallurgy of new and service-aged components.
Exhaust-valves made from a Ni-based γ’-strengthened Pyromet 31V were found to have operated at temperatures above the designed range. These exposure temperatures caused considerable coarsening and dissolution of the γ’ precipitates, increased grain boundary M23C6 carbides, and caused oxidation at and beneath the valve surfaces. ORNL extended this study to include TRW (WED’s valve supplier) to conduct aging experiments and analyses to define precise temperature limits for reliable exhaust valve use for the current alloy, and to define processing modifications, coatings or alternate alloys for improved performance and temperature capability.
ORNL, in collaboration with WED and TRW, plans to complete microstructural studies of both failed and unfailed valves, conduct the critical high-temperature creep and creep-fatigue tests to define properties/temperature limits, test coating benefits, and guide alloy selection for improved exhaust valve performance and reliability. The benefits of coated or improved alloys will also be assessed for their use with alternate fuels.
In FY 2005, ORNL and WED also began an effort to test and evaluate an upgraded cast exhaust manifold alloy with WED’s supplier, Stainless Foundry and Engineering (SF&E). Higher exhaust temperatures were causing creep in components made from Ni-resist austenitic cast-iron. The new CF8C-Plus cast austenitic stainless steel, developed by ORNL and Caterpillar, was used by SF&E to make new trial exhaust components, and test specimens for creep-testing. Creep-testing at ORNL demonstrates that the CF8C-Plus steel has almost 5 times the creep strength of Ni-resist cast iron at 700-750°C and above. The first CF8C-Plus exhaust manifolds cast were good enough quality to be considered for engine testing. |
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The
latest and archived Quarterly Progress Reports
are available in the on-line material in the Reports section.
Recent
Publications: Refer to the Bibliography section for more publications
J.P. Shingledecker, P.J. Maziasz, N.D. Evans, and M.J. Pollard, "Creep Behavior of a New Cast Austenitic Alloy," to be published in Proceedings of ECCC Conference on Creep and Fracture in High-Temperature Components - Design and Life-Assessment Issues, presented in London, September, 2005. (PDF 1.25MB)
N.D. Evans, P.J. Maziasz, and J.J. Truhan, "Phase Transformations During Service Aging of Ni-based Superalloy Pyromet 31V," to be published in Solid-Solid Phase Transformations in Inorganic Materials 2005, TMS, May-June 2005, Warrendale, PA. (PDF 2.14MB)
J. P. Shingledecker, P. J. Maziasz, D. Evans, and M. J. Pollard, “Alloy Additions for Improved Creep-Rupture Properties of a Cast Austenitic Alloy,” in Conf. Proc. Creep Deformation and Fracture, Design, and Life Extension, TMS, Warrendale, PA (2005), pp.129-138. (PDF 612KB)
Recent Presentations: Refer to the Bibliography section for more presentations
P. J. Maziasz, J.P. Shingledecker and N.D. Evans, “Alloy Additions for Improved Creep-Rupture Properties of a Cast Austenitic Stainless Steel – CF8C-Plus with Cu, W”, Symposium on Creep Deformation and Fracture, Design, and Life Extension, at MS&T’05, 25-28 September, 2005 Pittsburg, PA. (PDF 3.14MB)
J.P. Shingledecker, P. J. Maziasz, D. Evans, and M.J. Pollard, “Creep Behavior of a New Cast Austenitic Steel”, ECCC Creep Conference, London, UK, September 12, 2005. (PDF 2.18MB)
Development
of Catalytically Selective Electrodes for NOx and Ammonia Sensors
Contact:
Dr. Tim Armstrong
Oak Ridge National Laboratory
Bethel Valley Rd
PO Box 2008
Oak Ridge, TN 37831-6063
(865) 574-7996
armstrongt@ornl.gov
Sensor Element Geometry
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Concern for the environment is driving efforts to reduce pollutant emissions from mobile power sources and advanced natural gas reciprocating engine systems (ARES). Nitrogen oxides (NOx) are among the pollutants of primary concern. Unfortunately, no catalyst presently exists that can decompose NOx in the O2-rich exhausts from diesel and lean-burn gasoline engines. Thus techniques such as the lean NOx trap (LNT) and selective catalytic reduction (SCR) are being explored for NOx remediation. On-board NOx sensors are required for either approach, to control trap regeneration (LNT), or reagent injection (SCR). The amount of reagent injection during SCR is critical. Enough must be supplied to completely decompose the NOx without adding excess. Therefore, it is essential to develop sensors that can rapidly and accurately assess the NOx levels in these exhausts, and enable improved emissions control and on-board diagnostics. An ideal sensor would be operative at temperatures ~600°C, and able to measure NOx in the range 1–1000 ppm. This project seeks to develop and characterize NOx sensing elements (for incorporation into working sensors) targeted to meet these requirements.
An electrically-biased “total NOx” (approximately equal response to NO and NO2 over the range 5–500 ppm) sensing element was developed and tested. This is a significant accomplishment as the element will be unaffected by changing NO:NO2 ratios in the exhaust, thus eliminating the need for any type of NOx conversion in the working sensor. Testing and evaluation of the elements done in collaboration with Ford Motor Company have identified three key issues that will be the focus of future work: Stability of response, cross-sensitivity to ammonia and steam, and detailed understanding of the sensing mechanism. This understanding is important as ease and cost of fabrication may dictate changes in materials or electrode geometry during the incorporation of these elements into sensors suitable for use with reciprocating natural gas engines. Understanding of the sensing mechanism will be useful in predicting how such changes might affect the sensor performance. The
latest and archived Quarterly Progress Reports
are available in the on-line material in the Reports section.
Recent
Publications: Refer to the Bibliography section for more publications
D. L. West, F. C. Montgomery, and T. R. Armstrong. “NO-selective NOx sensing elements for combustion exhausts,” Sensors and Actuators B, 111-2, pp. 84, (2005). (PDF 454KB)
D. L. West, F. C. Montgomery, and T. R. Armstrong. “Electrically biased NOx sensing elements with coplanar electrodes,” Journal of the Electrochemical Society, 152 [6], H74–9, 2005. (PDF1,002KB)
D. L. West, F. C. Montgomery, and T. R. Armstrong. “Use of La0.85Sr0.15CrO3 in high-temperature NOx sensing elements,” Sensors and Actuators B, 106[2], pp. 758-765, (2005). (PDF 538KB)
Recent Presentations: Refer to the Bibliography section for more presentations
D. L. West, F. C. Montgomery, and T. R. Armstrong, “All-oxide “total NOx” sensing elements,” 207th Meeting of the Electrochemical Society, Quebec City, Canada, 2005. (PDF 501KB)
D. L. West, F. C. Montgomery, and T. R. Armstrong, “High-T NOx sensing elements using conductive oxides and Pt,” Proceedings of ICED: Engines for Mobile, Marine, Rail, Power Generation and Stationary Applications, Long Beach, CA, 2004. (PDF 799KB)
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