scholarly journals Comparison of Properties of Sintered and Sintered Reaction-Bonded Silicon Nitride Fabricated by Microwave and Conventional Heating

1994 ◽  
Vol 347 ◽  
Author(s):  
Terry N. Tiegs ◽  
James O. Kiggans ◽  
H. T. Lin ◽  
Craig A. Willkens
Keyword(s):  
Silicon Nitride ◽  
Grain Growth ◽  
Raw Materials ◽  
Cost Effective ◽  
Conventional Heating ◽  
Structural Applications ◽  
One Step ◽  
Powder Compacts ◽  
Fabrication Parameters ◽  
Sintered Silicon

ABSTRACTA comparison of microwave and conventional processing of silicon nitride-based ceramics was performed to identify any differences between the two, such as improved fabrication parameters or increased mechanical properties. Two areas of thermal processing were examined: (1) sintered silicon nitride (SSN) and (2) sintered reaction-bonded silicon nitride (SRBSN). The SSN powder compacts showed improved densification and enhanced grain growth. SRBSN materials were fabricated in the microwave with a one-step process using cost-effective raw materials. The SRBSN materials had properties appropriate for structural applications. Observed increases in fracture toughness for the microwave processed SRBSN materials were attributable to enhanced elongated grain growth.

scholarly journals Microwave Processing of Silicon Nitride for Advanced Gas Turbine Applications

1993 ◽  
Author(s):  
Terry N. Tiegs ◽  
James O. Kiggans
Keyword(s):  
Silicon Nitride ◽  
Gas Turbine ◽  
Raw Materials ◽  
Cost Effective ◽  
Microwave Processing ◽  
Heat Treated ◽  
Materials Used ◽  
Lower Temperature ◽  
Powder Compacts ◽  
Temperature Applications

The results from previous studies on microwave processing of silicon nitride-based ceramics are reviewed to ascertain the application of this technology to advanced gas turbine (AGT) materials. Areas of microwave processing that have been examined in the past are (1) sintering of powder compacts; (2) heat-treatment of dense materials; and (3) nitridation of Si for reaction-bonded silicon nitride. The sintering of Si3N4 powder compacts showed improved densification and enhanced grain growth. However, the high additive levels required to produce crack-free parts generally limit these materials to low temperature applications. Improved high-temperature creep resistance has been observed for microwave heat-treated materials and therefore has application to materials used in highly demanding service conditions. In contrast to Si3N4, Si couples well in the microwave and sintered reaction-bonded silicon nitride materials have been fabricated in a one-step process with cost-effective raw materials. However, these materials are also limited to lower temperature applications, under about 1000°C.

Sintered Reaction-Bonded Silicon Nitride by Microwave Heating

1992 ◽  
Vol 287 ◽  
Author(s):  
Terry N. Tiegs ◽  
James O. Kiggans ◽  
Kristin L. Ploetz
Keyword(s):  
Silicon Nitride ◽  
Flexural Strength ◽  
High Purity ◽  
Reaction Times ◽  
Raw Material ◽  
Firing Process ◽  
Step Process ◽  
Metal Parts ◽  
One Step ◽  
Sintered Silicon

ABSTRACTSintered silicon nitride has many desired properties, however, for most applications these materials are too expensive to compete with metal parts. Sintered reaction-bonded silicon nitride (SRBSN) is more economical, with raw material costs <27% those of comparable high-purity materials, making it competitive with metal parts. Conventional processing of SRBSN requires long nitridation times and a two-step firing process. Microwave (MW) heating reduces the reaction times and is performed in a one-step process, thereby simplifying the operation. The flexural strength of the MW-SRBSN is equivalent to the strength of some materials made from higher-cost powders. Thus, these materials may be appropriate for a number of applications.

Grain growth in millimeter wave sintered silicon nitride ceramics

2004 ◽  
Vol 24 (12) ◽  
pp. 3337-3343 ◽  
Author(s):  
M. Hirota ◽  
M.C. Valecillos ◽  
M.E. Brito ◽  
K. Hirao ◽  
M. Toriyama
Keyword(s):  
Silicon Nitride ◽  
Grain Growth ◽  
Millimeter Wave ◽  
Nitride Ceramics ◽  
Sintered Silicon

Cost Analysis of Using Hybrid Microwave Post-Sintered Silicon Nitride Inserts

2015 ◽  
Vol 1115 ◽  
pp. 192-195
Author(s):  
Tasnim Firdaus Ariff ◽  
Mohammad Iqbal ◽  
Rubina Bahar
Keyword(s):  
Silicon Nitride ◽  
Cost Analysis ◽  
Tool Life ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
Conventional Heating ◽  
High Fracture ◽  
Cutting Speeds ◽  
Sintered Silicon

Heat treatment is a process often used to improve product performance by increasing the strength of material or other desirable characteristics. Silicon nitride (Si3N4) tool insert is known for its attractive properties including high fracture toughness, strength and wear resistance at elevated temperatures. Heat treating these inserts by post-sintering them for 15 minutes at 600°C using conventional heating and hybrid microwave energy has prolonged tool life by 11-21% and 48-94% respectively. Machining was performed on a T6061 Aluminium alloy rod for tool life analysis at three different cutting speeds; 215, 314 and 393 m/min. Cost analysis is performed on these post-sintered Si3N4 inserts and found that there are economical benefits in the tooling cost when compared with the untreated Si3N4 inserts.

scholarly journals Fabrication of Turbine Components and Properties of Sintered Silicon Nitride

1982 ◽  
Author(s):  
J. T. Neil ◽  
K. W. French ◽  
C. L. Quackenbush ◽  
J. T. Smith
Keyword(s):  
Silicon Nitride ◽  
Injection Molding ◽  
Turbine Blades ◽  
Status Report ◽  
Injection Molding Process ◽  
Molding Process ◽  
Radial Turbine ◽  
Structural Applications ◽  
Injection Molded ◽  
Sintered Silicon

This paper presents a status report on the injection molding of sinterable silicon nitride at GTE Laboratories. The effort involves fabrication of single axial turbine blades and monolithic radial turbine rotors. The injection molding process is reviewed and the fabrication of the turbine components discussed. Oxidation resistance and strength results of current injection molded sintered silicon nitride as well as dimensional checks on sintered turbine blades demonstrate that this material is a viable candidate for high temperature structural applications.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

FERRIUM M54

Alloy Digest ◽  
2018 ◽  
Vol 67 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Resistance ◽  
High Strength ◽  
Cost Effective ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Structural Applications ◽  
Resistance To Stress

Abstract Ferrium M54 was designed to create a cost-effective, ultra high-strength, high-fracture toughness material with a high resistance to stress-corrosion cracking for use in structural applications. This datasheet provides information on composition, hardness, and tensile properties as well asfatigue. Filing Code: SA-822. Producer or source: QuesTek Innovations, LLC.

Calorimetric Sensor for Ethanol Using Ni2+-nitrilotriacetic Acid (NTA) Resin Immobilized Alcohol Dehydrogenase (ADH)

2020 ◽  
Vol 16 (6) ◽  
pp. 795-799
Author(s):  
YongJin Li
Keyword(s):  
Cost Effective ◽  
Nitrilotriacetic Acid ◽  
Repeated Measurements ◽  
Great Promise ◽  
Calorimetric Sensor ◽  
Controlled Pore Glass ◽  
Pore Glass ◽  
One Step ◽  
Immobilization Matrix ◽  
Enzyme Thermistor

Background: A simple, fast and economic analytical method for the determination of ethanol is important for clinical, biological, forensic and physico-legal purposes. Methods: Ni2+-NTA resin was used as an immobilization matrix for the simple one-step purification/ immobilization of his6-tagged ADH. Different alcohols with a concentration range of 0.5-50% V/V, namely methanol, ethanol and propanol were measured using prepared ADH enzyme thermistor. The ethanol content of Tsingtao beer was tested as a real sample containing alcohol. Reproducibility and stability of prepared ADH enzyme thermistor were also investigated by repeated measurements. Results: In comparison to the controlled pore glass (a common used support for the immobilization of enzyme) used in thermal biosensor, the use of Ni2+-NTA resin not only led to simple one-step purification/ immobilization by his6-tagged ADH binding to Ni2+-NTA resin, but also made the immobilizing supports reusable. The prepared biosensor can be used to determine ethanol and methanol by the calorimetric measurement. A linear range of 1 -32% (V/V) and 2-20% (V/V) was observed for ethanol and methanol, respectively. The detection limits were 0.3% (V/V) and 1% (V/V) for ethanol and methanol, respectively. The tested ethanol concentration of Tsingtao beer was 4.5% V/V, which is comparable with the labeled alcohol by volume (ABV) 4.80%. Conclusion: Ni2+-NTA resin, as an immobilization matrix in ET sensor, provides a simple one-step purification/immobilization for His6-tagged recombinase and a reusable immobilization matrix. The prepared biosensor exhibits good repeatability and stability. Such a new biosensor shows great promise for rapid, simple, and cost-effective analysis of ethanol and methanol, both in qualitative and in quantitative tests.

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