Rapid Aging of Diesel Lean NOx Traps by High-Temperature Thermal Cycling

2007 ◽  
Author(s):  
Ke Nguyen ◽  
Hakyong Kim ◽  
Bruce G. Bunting ◽  
Todd J. Toops ◽  
Cheon S. Yoon
Keyword(s):  
High Temperature ◽  
Thermal Cycling ◽  
Lean Nox ◽  
Lean Nox Traps

Advantages of MgAlOx over γ-Al2O3 as a Support Material for Potassium-Based High-Temperature Lean NOx Traps

ACS Catalysis ◽  
2015 ◽  
Vol 5 (8) ◽  
pp. 4680-4689 ◽  
Author(s):  
Jinyong Luo ◽  
Feng Gao ◽  
Ayman M. Karim ◽  
Pinghong Xu ◽  
Nigel D. Browning ◽  
...  
Keyword(s):  
High Temperature ◽  
Support Material ◽  
Lean Nox ◽  
Lean Nox Traps

KUBOTA ALLOY KHR12C

Alloy Digest ◽  
1999 ◽  
Vol 48 (3) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Thermal Cycling ◽  
Tensile Properties ◽  
Casting Alloy ◽  
Type Ii ◽  
Temperature Performance

Abstract Kubota alloy KHR12C is an austenitic Fe-Cr-Ni-Nb casting alloy developed from the well known HH type II grade. This alloy is superior to other grades in components that are subjected to frequent thermal cycling and shock. The alloy is available in both centrifugal and static castings. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: SS-738. Producer or source: Kubota Metal Corporation.

scholarly journals High temperature x-ray diffraction of zr-2.5nb during thermal cycling in vacuum

2017 ◽  
Vol 110 ◽  
pp. 01084 ◽  
Author(s):  
Mikhail Tumanov ◽  
Lyudmila Lyubimova ◽  
Evgeniy Puzyrev
Keyword(s):  
High Temperature ◽  
Thermal Cycling ◽  
X Ray Diffraction ◽  
X Ray

Cyclone Maintenance Improvement via Special Refractory Anchor Pin Studs

2004 ◽  
Author(s):  
Stephen R. Swartz
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Thermal Cycling ◽  
Thermal Spray ◽  
Effective Means ◽  
Protective Layer ◽  
Spray Coating ◽  
Cycle Performance ◽  
Alloy 625 ◽  
430 Stainless Steel

Since the inception of the cyclone style boiler, industry has become accustomed to performing routine maintenance during every scheduled shutdown occurring 12 months to 18 months between cycles. These maintenance cycles are influenced by service factor, loading and the type design. The same problems exist in both the standard and super critical cyclones; severe deterioration of refractory and the anchoring pin studs. This paper focuses on one type of refractory failure mechanism caused by the anchoring pin studs. Most operators have found that the most effective means of applying refractory in this type situation is to “ram” the refractory in and around the anchoring pin studs thus creating a dense lining with maximum integrity. Coupled with proper application of anchoring pin studs and a special designed coating, typical volumetric expansion of the pin studs from corrosion attack and oxidation is eliminated thus extending the life of the refractory. This mechanism is discussed along with the results of the coating performance as it relates to extreme heat oxidation and thermal cycling in laboratory tests. A protective coating was developed using a nano-cored thermal spray wire technology that produces a uniform, adherent protective layer against high temperature corrosion and oxidation. The coating yields similar thermal conductivity as a bare stud thus experiencing excellent thermal cycle performance. This specially designed thermal spray coating is applied to standard 430 stainless steel pin studs thus providing the necessary barrier against aggressive high temperature environments while maintaining excellent heat conductivity. The coating has a high amount of tungsten (40+%) in a nickel matrix with greatly reduced oxides at the substrate and throughout the coating. With these attributes for the anchoring pin studs in mind, a newly designed stud was evaluated in heat oxidation tests up to 2000°F and thermal cycling test and compared to 430 stainless steel, chromized and Alloy 625. The new stud out-performed all others even in the as-welded condition. Further corrosion testing in ferric chloride (ASTM G48) showed them to be superior to Alloy 72 and Alloy 625 in the thermal spray and welded condition. Proper welding equipment and welding techniques are also discussed since weld continuity impacts overall performance of anchoring pin studs with refractory linings. A major test site will be examined in the spring of 2004 for it’s full effectiveness in service and will be documented in order that all data retrieved would be available to the entire industry.

Study on Thermal Cycling of Sn0.7Cu Solder

2013 ◽  
Vol 791-793 ◽  
pp. 362-365
Author(s):  
Li Yang ◽  
Ju Li Li ◽  
Jing Guo Ge ◽  
Meng Li ◽  
Nan Ji
Keyword(s):  
Shear Stress ◽  
Steady State ◽  
High Temperature ◽  
Thermal Cycling ◽  
Shear Strain ◽  
Maximum Shear Stress ◽  
Steady State Creep ◽  
Maximum Shear Strain ◽  
Cycle Number ◽  
State Cycle

Thermal cycling of a unit Sn0.7Cu solder was studied based on the steady-state creep constitutive equation and Matlab software. The results show that there is a steady-state cycle for the thermal cycling of unit Sn0.7Cu eutectic solder. In steady-state thermal cycling, the shear stress is increased with the increase of temperature. There is a stage of stress relaxation during high temperature. A liner relationship between maximum shear stress and maximum shear strain is observed during thermal cycling. The metastable cycle number is declined greatly with the increase of maximum shear strain.

scholarly journals LC/8YSZ TBCs Thermal Cycling Life and Failure Mechanism under Extreme Temperature Gradients

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1051
Author(s):  
Kun Liu ◽  
Xi Chen ◽  
Kangping Du ◽  
Yu Wang ◽  
Jinguang Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Temperature ◽  
Thermal Cycling ◽  
Thermal Shock ◽  
Failure Mechanism ◽  
Extreme Temperature ◽  
Temperature Gradients ◽  
Accelerated Life Test ◽  
Ceramic Layer ◽  
Cycling Life

The purpose of this paper is to study the thermal shock resistance and failure mechanism of La2Ce2O7/8YSZ double-ceramic-layer thermal barrier coatings (LC/8YSZ DCL TBCs) under extreme temperature gradients. At high surface temperatures, thermal shock and infrared temperature measuring modules were used to determine the thermal cycling life and insulation temperature of LC/8YSZ DCL TBCs under extreme temperature gradients by an oxygen–acetylene gas flame testing machine. A viscoelastic model was used to obtain the stress and strain law of solid phase sintering of a coating system using the finite element method. Results and Conclusion: (1) Thermal cycling life was affected by the surface temperature of LC/8YSZ DCL TBCs and decreased sharply with the increase of surface temperature. (2) The LC ceramic surface of the failure coating was sintered, and the higher the temperature, the faster the sintering process. (3) Accelerated life test results showed that high temperature thermal cycling life is not only related to thermal fatigue of ceramic layer, but is also related to the sintering degree of the coating. (4) Although the high temperature thermal stress had great influence on the coating, great sintering stress was produced with sintering of the LC ceramic layer, which is the main cause of LC/8YSZ DCL TBC failure. The above results indicate that for new TBC ceramic materials, especially those for engines above class F, their sinterability should be fully considered. Sintering affects the thermal shock properties at high temperature. Our research results can provide reference for material selection and high temperature performance research.

Study of Damage Processes in Plasma Sprayed Bond Coat Under Thermal Cycling

1998 ◽  
Author(s):  
P. Bonnet ◽  
S. Abboudl ◽  
B. Normand
Keyword(s):  
High Temperature ◽  
Thermal Cycling ◽  
Bond Coat ◽  
Gas Turbines ◽  
Temperature Oxidation ◽  
Bond Coating ◽  
Engine Efficiency ◽  
Thermal Barriers ◽  
Plasma Sprayed ◽  
Damage Processes

Abstract Plasma sprayed thermal barriers are used as insulating materials in the hot sections of gas turbines to decrease the metal temperatures during service and men allow a higher combustion temperature for better engine efficiency. They usually contain a bond coating to protect the substrate from high temperature oxidation and a top coat with a low thermal conductivity. This study evaluate and identify the mechanisms of degradation of a vacuum plasma sprayed NiCoCrAlYTa bond coat subjected to thermal cycling at high temperature. The microstructure and micro-composition of the coating layer were analyzed by scanning electron microscopy and energy dispersive X-ray analysis to elucidate the improvement and degradation mechanisms of the material. The thermal cycling provokes some morphological and chemical modifications changes within this material. These modifications provoke a perturbation of the heat transfer within the material.

Active and Passive Devices Embedded in Laminate-Based Multilayer Board

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 001253-001283
Author(s):  
Satoshi Okude ◽  
Kazushisa Itoi ◽  
Masahiro Okamoto ◽  
Nobuki Ueta ◽  
Osamu Nakao
Keyword(s):  
High Temperature ◽  
Thermal Cycling ◽  
Flip Chip ◽  
Wafer Level ◽  
Active Device ◽  
Electrical Connection ◽  
Passive Devices ◽  
High Temperature Storage ◽  
Circuit Resistance ◽  
Temperature Storage

We have developed active and passive devices embedded multilayer board utilizing our laminate-based WLCSP embedding technology. The proposed embedded board is realized by laminating plural circuit formed polyimide films together by adhesive with thin devices being arranged in between those polyimide layers. The electrical connection via has a filled via structure composed of the alloy forming conductive paste which ensures high reliable connection. The embedded active device is WLCSP which has no solder bump on its pads therefore the thickness of the die is reduced to 80 microns. The embedded passive device is a chip resistor or capacitor whose thickness is 150 microns with copper electrodes. The electrical connection between components and board's circuits are made by same conductive paste vias. The thin film based structure and low profile devices yields the 260 microns thickness board which is the thinnest embedded of its kind in the world. To confirm the reliability of the embedded board, we have performed several reliability tests on the WLCSP and resistors embedded TEG board of 4 polyimide/5 copper circuit layers. As environmental tests, we performed a moisture reflow test compliant to JEDEC MSL2 followed by a thermal cycling test (−55 deg.C to 125 deg.C, 1000cycles) and a high temperature storage test (150 deg.C). All tested samples passed the moisture reflow test and showed no significant change of circuit resistance after the thermal cycling/high temperature storage tests. Moreover, mechanical durability of the board was also confirmed by bending the devices embedded portion. The embedded device was never broken and the circuit resistance change was also within acceptable range. The proposed embedded board will open up a new field of device packaging. Alan/Rey ok move from Flip Chip and Wafer Level Packaging 1-3-12.

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