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Title: Evaluation and silicon nitride internal combustion engine components. Final report, Phase I

Abstract

The feasibility of silicon nitride (Si{sub 3}N{sub 4}) use in internal combustion engines was studied by testing three different components for wear resistance and lower reciprocating mass. The information obtained from these preliminary spin rig and engine tests indicates several design changes are necessary to survive high-stress engine applications. The three silicon nitride components tested were valve spring retainers, tappet rollers, and fuel pump push rod ends. Garrett Ceramic Components` gas-pressure sinterable Si{sub 3}N{sub 4} (GS-44) was used to fabricate the above components. Components were final machined from densified blanks that had been green formed by isostatic pressing of GS-44 granules. Spin rig testing of the valve spring retainers indicated that these Si{sub 3}N{sub 4} components could survive at high RPM levels (9,500) when teamed with silicon nitride valves and lower spring tension than standard titanium components. Silicon nitride tappet rollers showed no wear on roller O.D. or I.D. surfaces, steel axles and lifters; however, due to the uncrowned design of these particular rollers the cam lobes indicated wear after spin rig testing. Fuel pump push rod ends were successful at reducing wear on the cam lobe and rod end when tested on spin rigs and in real-world race applications.

Authors:
 [1]
  1. Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (United States); Allied-Signal Aerospace Co., Torrance, CA (United States). Garrett Ceramic Components Div.
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10191276
Report Number(s):
ORNL/Sub-89-SE500/1
ON: DE93003628
DOE Contract Number:
AC05-84OR21400
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Apr 1992
Country of Publication:
United States
Language:
English
Subject:
33 ADVANCED PROPULSION SYSTEMS; 36 MATERIALS SCIENCE; SILICON NITRIDES; FABRICATION; EVALUATION; INTERNAL COMBUSTION ENGINES; MATERIALS; PROGRESS REPORT; WEAR RESISTANCE; MATERIALS TESTING; VALVES; PUMPS; AUTOMOTIVE ACCESSORIES; CERAMICS; MACHINING; 330100; 360201; 360203; PREPARATION AND FABRICATION; MECHANICAL PROPERTIES

Citation Formats

Voldrich, W. Evaluation and silicon nitride internal combustion engine components. Final report, Phase I. United States: N. p., 1992. Web. doi:10.2172/10191276.
Voldrich, W. Evaluation and silicon nitride internal combustion engine components. Final report, Phase I. United States. doi:10.2172/10191276.
Voldrich, W. Wed . "Evaluation and silicon nitride internal combustion engine components. Final report, Phase I". United States. doi:10.2172/10191276. https://www.osti.gov/servlets/purl/10191276.
@article{osti_10191276,
title = {Evaluation and silicon nitride internal combustion engine components. Final report, Phase I},
author = {Voldrich, W.},
abstractNote = {The feasibility of silicon nitride (Si{sub 3}N{sub 4}) use in internal combustion engines was studied by testing three different components for wear resistance and lower reciprocating mass. The information obtained from these preliminary spin rig and engine tests indicates several design changes are necessary to survive high-stress engine applications. The three silicon nitride components tested were valve spring retainers, tappet rollers, and fuel pump push rod ends. Garrett Ceramic Components` gas-pressure sinterable Si{sub 3}N{sub 4} (GS-44) was used to fabricate the above components. Components were final machined from densified blanks that had been green formed by isostatic pressing of GS-44 granules. Spin rig testing of the valve spring retainers indicated that these Si{sub 3}N{sub 4} components could survive at high RPM levels (9,500) when teamed with silicon nitride valves and lower spring tension than standard titanium components. Silicon nitride tappet rollers showed no wear on roller O.D. or I.D. surfaces, steel axles and lifters; however, due to the uncrowned design of these particular rollers the cam lobes indicated wear after spin rig testing. Fuel pump push rod ends were successful at reducing wear on the cam lobe and rod end when tested on spin rigs and in real-world race applications.},
doi = {10.2172/10191276},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Apr 01 00:00:00 EST 1992},
month = {Wed Apr 01 00:00:00 EST 1992}
}

Technical Report:

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  • The purpose of joining, Phase 2 was to develop joining technologies for HIP`ed Si{sub 3}N{sub 4} with 4wt% Y{sub 2}O{sub 3} (NCX-5101) and for a siliconized SiC (NT230) for various geometries including: butt joins, curved joins and shaft to disk joins. In addition, more extensive mechanical characterization of silicon nitride joins to enhance the predictive capabilities of the analytical/numerical models for structural components in advanced heat engines was provided. Mechanical evaluation were performed by: flexure strength at 22 C and 1,370 C, stress rupture at 1,370 C, high temperature creep, 22 C tensile testing and spin tests. While the siliconmore » nitride joins were produced with sufficient integrity for many applications, the lower join strength would limit its use in the more severe structural applications. Thus, the silicon carbide join quality was deemed unsatisfactory to advance to more complex, curved geometries. The silicon carbide joining methods covered within this contract, although not entirely successful, have emphasized the need to focus future efforts upon ways to obtain a homogeneous, well sintered parent/join interface prior to siliconization. In conclusion, the improved definition of the silicon carbide joining problem obtained by efforts during this contract have provided avenues for future work that could successfully obtain heat engine quality joins.« less
  • Techniques were developed to produce reliable silicon nitride to silicon nitride (NCX-5101) curved joins which were used to manufacture spin test specimens as a proof of concept to simulate parts such as a simple rotor. Specimens were machined from the curved joins to measure the following properties of the join interlayer: tensile strength, shear strength, 22 C flexure strength and 1370 C flexure strength. In parallel, extensive silicon nitride tensile creep evaluation of planar butt joins provided a sufficient data base to develop models with accurate predictive capability for different geometries. Analytical models applied satisfactorily to the silicon nitride joinsmore » were Norton's Law for creep strain, a modified Norton's Law internal variable model and the Monkman-Grant relationship for failure modeling. The Theta Projection method was less successful. Attempts were also made to develop planar butt joins of siliconized silicon carbide (NT230).« less
  • Techniques were developed to produce reliable ceramic-ceramic joins and analytical models were developed to predict the mechanical performance of the joins at room and elevated temperatures. Si{sub 3}N{sub 4}-4% Y{sub 2}O{sub 3} (Norton NCX-5100) and {beta}-Sic (Norton NCX-4500) were joined to themselves in the green state prior to final densification. The joins and controls were chemically and mechanically characterized at room and elevated temperatures to prepare the data banks for analytical modeling. Analytical models combining finite element and probabilistic software were developed that are capable of predicting the reliability of the joined components under fast fracture and creep.
  • The initial work on microwave annealing of dense silicon nitride showed enhanced grain growth and improved creep resistance for materials annealed at temperatures of 1,200--1500 C. In those tests, the anneal times were on the order of 10--20 h to achieve the observed changes. To further study the effectiveness of microwave annealing, a Cooperative Research and Development Agreement (CRADA) was started in the area of microwave processing of silicon nitride with Garrett Ceramic Components/Allied-Signal (GCC/AS). The original plan was for ORNL to microwave anneal specimens of dense silicon nitride with high additive contents (> 5%) provided by GCC/AS at variousmore » times and temperatures. There were to be three sample types and 3--4 annealing conditions for a total of 9--12 annealing runs. The materials would then be characterized by both ORNL and GCC/AS to determine any changes in the properties. The objectives were: (1) to determine the effects of microwave crystallization on mechanical properties, and (2) to compare the effectiveness of microwave versus conventional heating. The mechanical properties examined that were fracture toughness, flexural strength and high temperature stress rupture. Delays, organizational changes, and other commercialization priorities resulted in a termination of this CRADA. This report contains a summary of results from one silicon nitride composition.« less
  • This study assesses the feasibility of employing hydride fueled internal combustion engines to power mobile underground mining machinery. Problems are identified and solution and a development plan are proposed with the objective of constructing, testing, and demonstrating a nonpolluting engine suitable for underground use.