Microstructure Of

Pure Zr02 is polymorphic with a monolithic (m) structure up to approximately 1170 C the structure is tetragonal (t) up to 2260 C and above this temperature it is cubic (c). and MgO are most frequently used stabilizers in zirconia in order to suppress the transformation. One example of an acceptable microstructure is shown in Fig. 2. TRANSITION ELECTRON MICROSCOPE (TEN) STUDIES I.K. Technology I.K. Engineering has recently initiated transmission electron microcopy (TEM) studies of plasma sprayed...

I

0 4 6 8 10 12 14 16 18 20 22 24 26 Concentration o( Y203 in Zr02 wt Fig. 3. Spall resistance of zirconia coatings vs yttria content. Continuing to grossly summarize for brevity, the processing effect is that coating performance has been conclusively shown to depend strongly on process-related variables such as quality of the starting powder and porosity and residual stress distribution in the coating. Thus it follows almost axoimatically that process control and reproducibility of processing...

2106

Predicted Thermal Barrier Coating Lives on Turbine Blades Are Dependent Upon Aircraft Mission. Figure 11. Predicted Thermal Barrier Coating Lives on Turbine Blades Are Dependent Upon Aircraft Mission. Significant improvements in the life of EB PVD ceramic coatings are considered to be achievable and are the focus of development programs at Garrett. Densification of the outer surface of the zirconia should greatly inhibit the operation of the molten salt film damage mode....

Plasma Spray Processing

Fundamentals and Pre-1982 State-of-the-Art. Plasma spraying has been used for approximately 25 years in the gas turbine industry for application of protective coatings to various engine components. Basically, the material to be sprayed is introduced into the flow stream of a plasma torch, heated to its melting point while traversing the gun-to-workpiece standoff, and projected onto the component surface by the velocity of the gas stream. A schematic diagram of a torch and powder injector are...

Hohmana9 Wear Rig Correlation With Engine Results

The Hohman-A9 unlubricated ring liner wear performance correlated well with results from a LHR NTC-2 50 high temperature engine test. A 6 cylinder heavy duty diesel engine with a displacement of 855 in3 was operated for 300 hrs without cooling water at a top ring reversal temperature of 427 C. Because of the increased stress placed on the lubricant at the higher operating temperatures, coatings (tables 3 & 4) were used on the ring and liner surfaces to control wear. The plasma sprayed...

Summary

Gas turbine engines undergo a form of high temperature corrosion, called type 2 hot corrosion, when used in a marine environment. The parts most severely attacked are the metallic coatings used on the hot-section turbine blades. These coatings are often a mixture of cobalt, chromium, aluminum, and yttrium and, as a class, are identified by the acronym CoCrAlY. In several research efforts it has been found that increasing the chromium content of the coating to 30 or 40 wt from the originally...

1

10 IS 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 COATING TIME minutes ) 10 IS 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 COATING TIME minutes ) Temperature Variation at Rated Conditions Temperature Profile Coating Residual fable 2. Basic Strength Tests Conducted Coating Thickness was 2.5 mm 1 herma I Cycle Hi story CI, 1 Cycle CI , 5 Cycle

Introduction

Engineers have recognized since the early nineteenth century that the performance and efficiency of a heat engine improves with increasing operating temperature (ref. 1). However, maximum operating temperature are generally limited by the temperature capabilities of the materials used in the engine. Because of this, exotic superalloys and advanced cooling schemes have been developed for components in gas turbine engines. However, those technologies have now been pushed to near their limits....

Fig 23 To Obtain Data For Design

The thicknesses of these mixed layers will depend upon the analysis as shown in the next figure. Here the analysts have modeled the strains developed, at temperature, in a thermal barrier coating on a cast substrate. Figure 24 represents what actually would happen with a ceramic coated (non-graded) TBC on a cast iron cylinder head with a target of getting the conductance of 400 watts per meter squared degree C. 'FIG. 24. THERMAL STRAIN IN TTBC COATINGS CYLINDER HEAD What this figure shows is...

Program Accomplishments Lubrication

NBS has pioneered the development of instruments and methods to establish state-of-the-art technology for the analysis of lubricating films in boundary lubrication. An understanding of how lubricants work has begun to emerge and should lead to the development of new lubricant systems. The key advancement is in the unique way in which various analytical tools have been combined to give analytical chemical data. These include development of methods utilizing 4-ball wear tests in a combination...

Combustion Chamber

Thermal and mechanical loads on a diesel engine valve. axisymmetric finite element model of valve and coating geometry. axisymmetric finite element model of valve and coating geometry. 0.0 0.3 0.6 0.9 1.2 1.5 DISTANCE FROM COATING SURFACE, mm Figure 14. Transient behavior of circumferential stresses within the PSZ coating of intake valve. 0.0 0.3 0.6 0.9 1.2 1.5 DISTANCE FROM COATING SURFACE, mm Figure 14. Transient behavior of circumferential stresses within the PSZ coating of...

Tribology Within the Department of Defense

A survey of tribology activities currently being conducted in the various laboratories of the Army, Navy, and Air Force are described. This survey was conducted to give an insight to the breadth and scope of tribological studies being conducted to develop advanced materials for future weapon systems as well as to solve current lubrication problems in the field. The information presented is not in great detail but the organizations conducting the research, along with points of contact, are given...

High Temperature Trib0l0gy

The greatest single problem facing the adiabatic engine is the high tein perature tribology problem. In the ar'ea of the topring reversal-point on the cylinder liner, temperatures approach 550C for the uncooled adiabatic engine, compared with only 200C for the conventional water-cooled engine High temperature synthetic gas turbine lubricating oil has been used with some success at the lower outputs. However, at full loads (200 PSI BMEP), the hydrodynamic oil film protection at the topring...

Table

Other variables which influence the wear resistance and friction of coatings are listed in Table 2. Caterpillar's experience has shown that the surface finish of the coatings and the combination of the sliding pairs of materials greatly influence wear. We have used single cylinder engine tests to evaluate many ring and liner coating combinations. From this work it was concluded that a smooth surface finish on the order of 0.20-0.40 micron center line average roughness compared to 1.00 micron...

Acknowledgements

The authors wish to acknowledge the technical and financial support of Cummins Engine Company and the U.S. Army Tank-Automotive Command and within those organizations especially thank Ralph Slone, Earnest Schwartz and Walter Bryzik. We wish to thank also Mehmet Uras, George Schwartz, Guy Babbitt and George Miltsios who contributed in important ways to the success of this effort. Finally, we wish to thank Jack Brigham and Fred Rowe who helped us in critical ways including the manufacturing and...

Front Of Engine

Figure 2 Location of Coatings Within Engine which were run at the beginning and end of the 500-hour test. These parameters were monitored for only one uncoated cylinder (cylinder 1) and one coated cylinder (cylinder 12). A 500-hour engine test protocol was developed by the AAR with the assistance of the engine manufacturers, the oil refining companies, and the technical representatives from the railroads as a cost effective means of_ screening for early failures. Fuels and or components...

1440l0

Raman spectra of Diamond like Cartoon (DLC) film and PECVD diamond film. attributed to sp3 bonding in the material Large single crystal graphite displays a single high frequency line at about 1575 cmor 1580 cm as a result of sp2 bonding. Polycrystalline graphite exhibits a line at 1355 cm'1. Subsidiary peaks occur near the main peaks due to the presence of defects, mixed phases and second order spectra. The superior physical properties of diamond films, with particular reference to...

Discussion

The results of the study have shown that ceramics can make an important contribution to solving the wear problems experienced in advanced heat engines. Wear coefficients approaching those obtained with current conventional piston rings were measured using ceramic-based coatings and a synthetic lubricant at 260 C. Since monolithic ceramics may be difficult to apply in ring applications, the coatings offer a practical approach for using ceramics. The need for materials having inherently higher...

Info

Turbocharging System for the AVL Single-Cylinder Engine. rings and cylinder liners is also part of our program. In this section we highlight some of our progress to date. In particular, we emphasize our recent development of a low cost liquid lubricant, suitable for commercial diesel engine service, which considerably improves upon the performance of the best previous LHR engine lubricant. At the beginning of our program, we formulated a new general concept for high-temperature...

Coating Configuration Requirements

In order to achieve the above goals, the major parameters that have to be considered are 1. Coating substrate adherence. 2. Low residual stress in the coating and coating substrate interface. 3. Excellent oxidation resistance and low permeability of oxygen through the coating configuration. 4. Improved mechanical strength and tow coefficient of friction at room and elevated temperature and high thermal shock resistance. 5. Minimum chemical interaction between the substrate and the coating and...

14T E Fischer and H Tomizawa

Steijn, Wear 7 (1964) Effect of Atmosphere on the Wear Rate of Some Ceramics and Cements, Proc. Int'l. Conf. Wear of Mats., ASME, April 1977, St. Louis, MO, pp. 452461. 17. E. F. Finkin, S. J. Calabrese, M. B. Peterson, ASLE Preprint No. 72LC-7C-2 (1972). 18. L. B. Sibley and C. M. Allen, Wear 5 (1962) pp. 312-329. Technology, Inc. Evaluation of Improved Materials for Stationary Diesel Engines Operating on Residual and Coal Based Fuels, U.S. Department of Energy Contract No....

Conclusions

It has been demonstrated in a high temperature environment that a continuous uniform film can be formed on a variety of metal surfaces, as well as on a quartz surface. On all of these surfaces the rate of coating increases with increasing temperature over the 500 to 800 C temperature range studied. In all cases, the rate of deposit increased with increasing amounts of TCP vapor in the nitrogen carrier gas delivered to the hot test specimen. Quartz appeared to supply a noncatalytic solid surface...

Background

This paper will review the successful component types their function, the design approach, the environment in which they operate, the tests conducted to evaluate these components, the results, and the benefits derived. In general, the effort has been focused on ball-socket joints and flat 'wear pad1 surfaces of components variously described as 'overhead' components or 'valve and injector train' components. The environment in which these components operate is high quality lubricating oil with...

Heat Losses

The importance of the degree of insulation at full engine power As a consequence of the reduced temperature gradients in the substrate, heat transfer to the cooling water will be reduced. Fig. 7 shows how the heat flux to the cooling water in the cylinder head is reduced with increasing insulation of the heat exposed components. Initially the engine had no coating. At 29 hrs the piston was coated with a 1 mm thick ceramic coating and at 51 hrs the cylinder head, too, had been coated with...

4

Figure 4 - Gas Bearing Piston with Scotch Yoke Mechanism (Courtesy FICHT Gmbh) achieved by narrower passages to increase the exhaust gas velocity and use of a smaller turbine area. In order to prevent turbocharger overspeed, a waste-gate is used to vent excess pressure at the high power end. If the turbocharger match 1s for a coast-to-coast truck which operates a high percentage of time at full power and constant speed, then the turbocharger would be selected which had a high efficiency for the...

Turbine Components Corporation

Seventeen years ago the author worked on what was apparently the first application of a thermal barrier coating in a production gas turbine engine. The coating was applied to a louvered sheet metal transition duct in the hot section of the engine to alleviate a severe buckling, cracking and oxidation problem. The coating was bi-layered, consisting of a metallic bond coat and a top layer of zirconium oxide. The presence of the coating doubled the life of the part. For obvious reasons, this...

7cycle Chrome Oxide Densification

* KAMAN'S CHROME OXIDE IS APPLIED BY DENSIFYING A POROUS STRUCTURE WITH CHROMIC ACID, DRYING AND HEATING Figure 9. Chemical Thermal Barrier Coatings. Advanced thermal barrier coatings, as alternatives to thermal spray coatings, have been and are currently being explored. It is believed that the plasma spray coatings are limited and that residual stresses which are induced during the coating thermal spray processing cannot be completely eliminated. However, the residual stresses can be altered...

Wear Performance Without Lubrication

The monolithic ceramics in Table 1 were run self-mated at 1000 rpm, with temperatures from 290 to 540 C, a diesel exhaust atmosphere, and ring loadings from 1.6 to 7.7 N mm. The wear rates and friction coefficients were high. The ring specimens wore as much as 0.05 mm in 3 minutes, and the friction coefficient varied from 0.3 to 0.6. Extensive surface cracking and edge chipping occurred on the ring specimens. The Si3N4 and SiC ring specimens experienced large-scale fractures rapidly, while the...

Fig 25 Thermal Strain In Ttbc Coatings Cylinder Head Equal Thickness Layers

Figure 25 shows the prediction of what happens to the thermal strain when we spray these bond-coat ceramic mixtures in equal thicknesses using the same conductance goal. Because of the difference of thermal expansion of the mixtures, we greatly decrease the strain near the bond coat interface. Each coating layer produces a strain gradient based upon the expansion of the layer. The coating in this case ends up haying a mean strain of about 400 MPa in tension throughout the coating thickness...

145

N.B. test speed is very important at room temperature (EHD - boundary transition) Table III - List of Ring and Liner Coatings Tested in Uncooled NTC-250 Engine Piston Ring Coatings Cylinder Liner Coatings Table IV - Best Coating Combinations Found in Uncooled NTC-250 Tests Piston Ring Coatings Cylinder Liner Coatings

100 120

Four-Ball Wear Values at 370 C with Vapor Lubrication as a Function of TCP Vapor Concentration presented in this paper, gives a deposit rate of about two molecular layers of deposit per second at 370 C. The rotating ball in the four-ball wear tester provides the rubbing surface available for vapor deposition during the test. At 600 rpm and contact with the three stationary balls, there are 300 contacts per second for the rotating ball. Four-ball wear data are presented on Figure 8 for...

Powders

Investigation of various Y-O stabilized Zrt coating systems has snown the extreme importance of powder quality. The effects of wide variations in coating performance are thought to be due to chemical purity and homogeneity in addition to the powder morphology which reflects the manufacturing process. Examples of different powder morphologies are shewn in Fig. 4. Most of the powders used for thermal spraying have sizes between 150 urn and 5 um. The ideal powder is one where the grain size is...

References

Furuhama, S. and Enomoto, Y. (1987), Heat Transfer into Ceramic Combustion Wall of Internal Combustion Engines, SAE Paper 870153. Keribar, R. and Morel, T. (1987), Thermal Shock Calculations in I.C. Engines, SAE Congress, SAE Paper 870162. Morel, T. and Keribar, R. (1985), A Model for Predicting Spatially and Time Resolved Convective Heat Transfer in Bowl-in-Piston Combustion Chambers, SAE Paper 850204, SAE Congress, Detroit. Morel, T., Keribar, R. and Blumberg, P. N. (1985), Cyclical Thermal...

Abstract

The metallic coatings used to protect the hot-section turbine blades of marine gas turbines are often a mixture of cobalt, chromium, aluminum, and yttrium (CoCrAlY). Using the surface sensitive technique of x-ray photoelectron spectroscopy, the protective oxide scales on CoCrAlY coatings containing nominal levels of 20, 29, and 35 wt chromium were found to be essentially the same and were predominantly alumina and a yttrium rich phase that is tentatively identified as yttrium aluminum garnet....

180

Cylinder pressure (upper), strain gauge (center), and resulting friction force. WOT, 1000 rpm, motoring. Each engine presents a different challenge in so far as designing and applying the Fixed Sleeve method. Figure 15 shews a design created for the Cummins 903. At the left is a collar which is rigidly attached to the underside of the block. That collar has a necked-down section with strain gauges mounted inside and outside. The collar and liner bottom are both threaded. The liner is...

45

Coating intact although extensive reaction with salt, crystals of yttrium vanadate at the surface slight spallation of ceramic at button edges Some leaching of Y by the salt, slight attack of the bond coat Slight spallation of ceramic at button edges, slight bond coat attack, surface reaction with salt, regions of free ceria at the surface, local regions of cerium sulphate. crystals were detected by EDAX on the sputtered YSZ specimens these are presumably yttrium vanadates. On the PVD and...

1110

Cycle Simulation Studies Of the multitude of recently published cycle simulation studies of the effects of reduced heat rejection on fuel consumption, several have been chosen as indicative of the range of published results, and are summarized in Table 1. Each of these studies focused on heavy duty engines constrained as described previously - constant peak cylinder pressure. constant air-flow ratio. and unchanged heat release. What is more significant is that three of the analyses, those of...

Conclusions Of Translucence Study

Translucence was found to have a significant detrimental effect on the heat barrier effectiveness under realistic diesel engine conditions. It allows the radiation heat flux to pass through the ceramic and be directly deposited on the substrate. This increases the convective heat transfer and thus the total heat flux, which can increase by 50 and more over the opaque case. 2. The effects of translucence depend strongly on the material absorption and scattering coefficients. Significant effects...

107 60 50

Thus, compliance of production engines to meet the 1994 particulate levels means the design goal must be about 0.07 g bhp-hr in order to meet the 0.10 g bhp-hr limit. A cursory review of emissions work shows a relationship between NO and particulates such that engine conroustion parameter changes taken to reduce NO tend to increase particulates and vice versa. Emissions compliance with current production engines by timing modification would require timing retardation of fuel injection. This...

Table Ii Electromotive Division Diesel Engine 16645f3b

Cylinder Arrangement Compression Ratio Displacement per Cylinder Cylinder Bore Cylinder Stroke Operating Principle Full Speed Idle Speed for the 645 series of engines. It was introduced to the railroad industry as the prime mover for the new 60- series locomotives. The Model 710 engine has a stroke of 11.0 inches (279 mm) and a bore of 9.06 inches (230mm). Top engine speed has been reduced from the 959 RPM used for the 645F series engines to 900 RPM. The net effect of this change, combined with...

Raman Shift [lcm

Four percent yttria stabilized zirconia (as-received). Figure 26. Four percent yttria stabilized zirconia, aged 24 hours in 10 H20 at 250 C. Figure 26. Four percent yttria stabilized zirconia, aged 24 hours in 10 H20 at 250 C. Figure 27. Two percent yttria stabilized zirconia, aged 168 hours in vacuum. Figure 27. Two percent yttria stabilized zirconia, aged 168 hours in vacuum. Figure 28. Four percent yttria stabilized zirconia, aged 16 8 hours in vacuum. Figure 28. Four percent...

Problems And Solutions

Every wear test, whether for bulk materials or coatings can be complicated by problems with equipment, procedures, specimen preparation, inconsistencies in abrasive media, and in interpreting the test results. Rather than enumerating all the known problems with each wear test described above, several specific examples of some general problems in testing of coatings will be described along with some solutions. Thick coatings, such as those produced by thermal spray techniques and weld overlay...

Approach

The calculation of time-averaged heat fluxes and temperatures requires a time dependent heat transfer analysis of the heat transfer through the wall. Consequently, the computational study was carried out using a one-dimensional coupled conduction-radiation heat transfer model which describes the time-dependent heat flux through a partially translucent ceramic layer backed by an opaque metallic layer. The gas-side boundary conditions were supplied by the engine design analysis code IRIS. The...

The Need for Automation and Quality Control

Materials in gas turbine engines are often designed to operate near their durability limits, and this is certainly the case with thermal barrier coatings. Therefore, process optimization and automation backe,d by careful quality control procedures are essential during both research and production. (An example of the type of approach needed was presented at this conference by A1 Matarese from the United Technologies Research Center.) Inadequate attention to quality control generally leads to...

Llil

NiCrAlY BOND COAT 100 - 200 i.m (0.0039-0.0078) Figure 2. Plasma sprayed, yttria stabilized zirconia coating Figure 3. Ceramic coated valve face - original design *Numbers in parentheses designate references at end of paper. Figure 3. Ceramic coated valve face - original design where the yttria varied from 8 to 13. The base metal was prepared for coating by grit blasting and cleaning prior to applying the bond coat. For selected coating application, where minimum surface porosity or a harder,...

Fixed Sleeve Method

Parallel with the development of the Instantaneous IMEP method, a derivative of moveable bore methods termed the Fixed Sleeve method has been developed. To date this has been implemented on a 4.1 liter gasoline engine (7). Figure 13 shows a cross section of the Fixed Sleeve design. The original 4.1 litre engine liner which had an 88 mm bore is fitted with a smaller 80 mm sleeve which is attached to the outer liner by a pair of jam nuts located at the bottom of the assembly. Piano wire in...

Fig 4 Performance Results at 2000 RPM Showing Effect of LHR Engine Operation

Had no effect on indicated thermal efficiency (ITE) while slightly increasing the low load smoke and full load particulate emissions. The insulated engine at baseline conditions had significantly lower ITE, with higher smoke and particulate emissions (especially at full load) compared to the baseline uninsulated engine. Increasing the coolant temperature of the ceramic insulated engine slightly reduced the ITE at full load, and increased the lowest load particulate emissions compared to the...

Cooled Engine Experiments

The experimental part of the program is concerned with making detailed heat flux measurements in both conventionally cooled metallic engines and in ceramic coated insulated engines for the purpose of validating the in-cylinder gas phase heat transfer models which have been developed in this program. In the experiments carried out on the conventionally cooled metallic engine (single cylinder Cummins NH engine), a detailed set of heat transfer measurements was made over a matrix of engine speeds...

Applications

The objective of this work is to develop a comprehensive heat transfer and thermal analysis methodology oriented specifically to the design requirements of insulated diesel engines. The methodology is to make possible a quantitative analysis of the low heat rejection (LHR) engine concept, including the determination of performance improvements, identification of design strategies for optimum engine insulation, and a detailed characterization of the thermal environment in which structural...

Four Ball Wear At 10kq And 30

TCP AT 370 C UOUD LUBE AT 79 C maM mm 1 rsm iow ezzaa 11 i uto cants tested at the same load with 10 ml of liquid at 75 C. These data show that the optimum TCP vapor concentration gives less wear at 375 C than a fully flooded 75 C test with an SF-CD automotive lubricant. The low concentration TCP vapor phase run gives wear comparable to a good industrial EP lubricant. The last liquid lubricant in the comparison is a typical 30 weight oil with rust and oxidation protection. These data show...

Naval 8hip Research And Develop Center

Observations from a five-inch seal 3001 test machine marine tribology block program 700k asperity interaction i* mixed lubrication 0 nainshaft seals for surface ships 0 improved shipboard fuel contamination 100k fiber optics bearing performance monitoring ik pump development for deep submarines ik bearing acceptance testing and ik condition evaluation bearing stave materials study ik synthetic hydrocarbon hydraulic fluids ik ship lubricant reduction program 0 methods to determine lubricant...

Results And Discussion

The results of the various powder analyses are shown in Table 3. Included in the list are three powder groups from vendors A, H, and D added to the program after the program was well under way. These have an incomplete data list. While each material is unique, clearly the powders can be classified by their method of manufacture. In general, spray dried TBC powders have the lowest true density, the highest specific surface area, and the lowest mass flow rates of all powders. Sintered materials...

Wear Test Conditions

The following test conditions were selected for Cameron Plint friction and wear tests. The ring sample was oscillated against the liner at 20Hz using a 5 mm stroke. The normal load was 250 N. acting on a 12.7mm length of ring sample (19.7 Nmm-1 loading). For lubricated tests. oil was supplied at a rate of one drop every 10 seconds (10.8 cm3 hour). except where stated. Test durations were normally 6 hours for lubricated and one hour for unlubricated tests. In all cases, ring and liner samples...

11145

Advanced Ceramic Coatings For Marine Gas Turbine Engines D.J. Wortman & B.A. Nagaraj, Engineering Materials Technology Laboratories, General Electric Aircraft Engines 111-49 Development and Performance of Physical Vapor Deposition Thermal Barrier Coating Systems T.E. Strangman, Garrett Turbine Engine Company (GTEC), a Unit of Allied-Signal Inc. 111-63 Coatings for Diesel Engines and Associated Problems I. Kvernes & 0. Noerholm, IK Engineering 111-73 Design Criteria for a Coating to Reduce...

Iv29

Lubricated with mineral oil and water, to determine the effect of load and speed on friction and wear performance. The results show that at a specific load both the friction coefficient and the wear rate increase to a level comparable with the data in unlubricated tests. The magnitude of the transition load was found to depend on the lubricating fluid and the test speed. It was hypothesized that the transition is related to the contact temperature or tribo-chemical reactions. These results...

Instantaneous IMEP Method

The Instantaneous IMEP method employs a force balance between the measured cylinder pressure force, the compressive force in the connecting rod, the inertia force and the friction force. Considering the components of these forces acting along the cylinder axis, the sum of the other three equals the friction force of the piston, rings and piston pin assembly. Figure 1 shows a single cylinder version of the Cummins 903 V-8 engine modified for the Instantaneous IMEP method. The large pipe...

092

Meletis E., Carter W., Hocfntn R., 17th IMS Tech Meeting 3. Rcrcfiawa H., Jdnson P.C., Fed, Research g Development 1. Randrcwa H,, Johnson P.C., Cathodic Arc Plasma Deposition Process 5. Buishdi R,, Schrami R., TTiln Solid Films 10 (1977) Diamond Thin Films by Plasma Enhanced Chemical Vapor Deposition - The Emerging Technology for Hard Coatings

US Department of Energy

Rudolph Diesel received academic training in late 19th Century classical thermodynamics. About 100 years ago he was working in the Linde Ice Machine Company where he noted the large amount of heat given off by reciprocating ammonia compressors. This observation lead to his ideas about compressing air in a similar manner to over 10 times its initial volume such that the air temperature rose high enough to ignite an injected fuel charge. He first published a thermodynamic analysis of his engine...

S Danyluk SM Hsu and S Jahanmir

It has been estimated that the effective use and advances in tribology can save the U.S. economy 18 billion dollars per year, and 40 in the effective transfer of existing tribological expertise to practicing engineers and designers. A computerized numeric database with easy, quick access to both recommended practice as well as design codes will help to achieve this goal. A computerized database with validated numerical data, and best judgement values by experts will aid in establishing...

Coating Production

Bond coat Al-35Si (RST, new development) Grain size 38-90 urn Top coat a) 25 MgO ZrO- (Amperit) Grain size 10-53 um b) 8 Y203 Zr02 (Amperit) Grain size 10-70 um Coatings were deposited using an Eutronic Plasma 80 kw unit. A mixture of argon + 12 hydrogen plasma bearing gas was used. We have sprayed sane samples with a cermet (ceramic metallic mixture) layer (0.05 mm) in the ceramic coatings, approximately 0.5 mm apart in order to reduce the crack propagation in the coatings. A second type of...

Expenditures For Gasoline

High pay-off R& D on promising transportation heat engine propulsion conservation technologies has been constructed. This program aims to provide the automotive industry with proof-of-concepts for advanced engine technology with potential for fuel economy improvement on the order of 30 . Similarly the advanced diesel technology efforts are expected to provide the heavy duty transport industry with like fuel economy improvements. Supporting technologies are included in the program with...

Seaworthy Systems

The results of a 14,000-hour marine industry demonstration of thin ceramic coatings in diesel engine combustion components are truly encouraging. These superior ceramic coatings on the piston crowns, exhaust valves, and the heads have operated in everyday towboat operation for over two years and have demonstrated the durability needed for extended component lifetimes in commercial operation. These ceramic coated components have produced a smoother running engine, with a reduced cetane...

Future Coatings Development Work At Cummins

Cummins Engine Company has recently been awarded a Department of Energy contract to develop wear resistant ceramic coatings for diesel engine components (Program 86X SA581V). The objective of this program is to develop advanced wear resistant coatings for future, low heat rejection diesel engines. Coatings and substrates (for piston rings and cylinder liners) are to be developed to meet the following requirements. Low wear (as measured in laboratory rig tests at ambient and 350 C). Wear...

Thermal Barrier Coatings for Diesel Engine Components

An additional set of problems will be associated with the transfer of aerospace TBCs to diesel engines. This is partly because thicker coatings will be required to meet the insulation needs for most of the more advanced applications, and higher stresses are generally associated with thicker coatings. Currently NASA-Lewis is managing two DOE-sponsored contracts which are designed to develop thermal barrier coatings for truck diesel engines. (This program has been discussed at this conference)....

Iv26

Tribology Program structure Figur 2. Tribology Program structure higher speeds, power is transmitted through gear systems with higher efficiency. A major effort at NBS in 1987 was the assessment of the thermo-oxidative stability characteristics of synthetic oils. Thermal gravimetric analysis (TGA) and differential scanning catorimetry (DSC) methods were developed for this work. Basic property data were accumulated on poly-a-olefins (PAO), phosphate esters (PE), polyol esters (TMP),...

S

FIGURE 2 Wear rate as a function of temperature for conventional piston ring and cylinder liner materials tested with a 15W40 CE SF mineral oil based lubricant (Cameron plint data). FIGURE 3 Friction coefficient as a function of temperature for two different oil supply rates (one drop every 10 or 100 seconds) conventional ring and liner materials, commerical 15W40 CE SF mineral oil based lubricant. FIGURE 3 Friction coefficient as a function of temperature for two different oil supply rates...

556

Fraction and characteristic depth of the soot layer calculated for the center of the head of a heavy duty diesel engine. of the parameters. The absorption coefficient was varied from 10 m' (approaching fully transparent limit) to 10 m l (approaching fully opaque limit). The scattering coefficient was varied over the same range of values, and the back-scattering coefficient was varied over the same range of values, and the back-scattering fraction from 0.05 to 0.5. The refractive index of the...

13

Compression n0- 2 Expansion Compression n0- 2 Expansion Figure 1. Temperature Profile adjacent to combustion chamber wall at various times in the Figure 1. Temperature Profile adjacent to combustion chamber wall at various times in the Ikegami went on to demonstrate the impact of such phenomena on an insulated engine. An increase in wall temperature of 300 degrees C was calculated to result in a reduction in peak heat flux slightly over ten percent. This compares with values on the order of 50...