scholarly journals High Strength Si3N4 Ceramics

1989 ◽  
Vol 97 (1128) ◽  
pp. 872-874 ◽  
Author(s):  
Yoshio UKYO ◽  
Shigetaka WADA
Keyword(s):  
High Strength ◽  
Si3n4 Ceramics

HREM interface studies in SiC-whisker-reinforced Al2O3 and Si3N4 ceramics

1988 ◽  
Vol 46 ◽  
pp. 734-735
Author(s):  
W. Braue ◽  
R.W. Carpenter ◽  
D.J. Smith
Keyword(s):  
Analytical Data ◽  
Base Material ◽  
High Strength ◽  
Ceramic Composites ◽  
Good Thermal Stability ◽  
All Ceramic ◽  
Sic Whiskers ◽  
Base Composite ◽  
C 30 ◽  
Si3n4 Ceramics

Whisker and fiber reinforcement has been established as an effective toughening concept for monolithic structural ceramics to overcome limited fracture toughness and brittleness. SiC whiskers in particular combine both high strength and elastic moduli with good thermal stability and are compatible with most oxide and nonoxide matrices. As the major toughening mechanisms - crack branching, deflection and bridging - in SiC whiskenreinforced Al2O3 and Si3N41 are critically dependent on interface properties, a detailed TEM investigation was conducted on whisker/matrix interfaces in these all-ceramic- composites.In this study we present HREM images obtained at 400 kV from β-SiC/α-Al2O3 and β-SiC/β-Si3N4 interfaces, as well as preliminary analytical data. The Al2O3- base composite was hotpressed at 1830 °C/60 MPa in vacuum and the Si3N4-base material at 1725 °C/30 MPa in argon atmosphere, respectively, adding a total of 6 vt.% (Y2O3 + Al2O3) to the latter to promote densification.

scholarly journals High Strength Si3N4 Ceramics and its Application for Automotive Parts.

1994 ◽  
Vol 60 (9) ◽  
pp. 1263-1267 ◽  
Author(s):  
Takao Nishioka ◽  
Kaoru Murabe ◽  
Kenji Matsunuma ◽  
Akira Yamakawa ◽  
Masaya Miyake
Keyword(s):  
High Strength ◽  
Automotive Parts ◽  
Si3n4 Ceramics

Comparative study of oxide and non-oxide additives in high thermal conductive and high strength Si3N4 ceramics

2016 ◽  
Vol 42 (15) ◽  
pp. 17466-17471 ◽  
Author(s):  
Hyun Min Lee ◽  
Eun Bok Lee ◽  
Dong Lae Kim ◽  
Do Kyung Kim
Keyword(s):  
Comparative Study ◽  
High Strength ◽  
Si3n4 Ceramics

Preparation of Si3N4 ceramics with high strength and high reliability via a processing strategy

2002 ◽  
Vol 22 (8) ◽  
pp. 1347-1355 ◽  
Author(s):  
Longjie Zhou ◽  
Yong Huang ◽  
Zhipeng Xie ◽  
André Zimmermann ◽  
Fritz Aldinger
Keyword(s):  
High Reliability ◽  
High Strength ◽  
Processing Strategy ◽  
Si3n4 Ceramics

Effect of Diluents on Post-Reaction Sintering of Silicon Nitride Ceramics

2007 ◽  
Vol 352 ◽  
pp. 185-188 ◽  
Author(s):  
Toru Wakihara ◽  
Masahiro Yabuki ◽  
Junichi Tatami ◽  
Katsutoshi Komeya ◽  
Takeshi Meguro ◽  
...  
Keyword(s):  
Bending Strength ◽  
Exothermic Reaction ◽  
High Strength ◽  
Cost Effective ◽  
Raw Material ◽  
Reaction Sintering ◽  
Oxygen Donor ◽  
Nitride Ceramics ◽  
Si3n4 Ceramics

Post-reaction sintering as a technique for the fabrication of Si3N4 ceramics has received much attention as a cost-effective process due to the use of cheap Si powder as a raw material. In this method, the rapid exothermic nitridation of Si results in local melting of Si to cause its agglomeration, which is expected to be a flaw after densification. Therefore, control of the exothermic reaction is needed to improve the reliability of post-reaction sintered Si3N4 ceramics. In this study, Si3N4 ceramics were fabricated by post-reaction sintering with Si3N4 or SiO2 powders in order to control the exothermic reaction. As a result, the microstructure and bending strength of Si3N4 ceramics was changed by adding these additives. In particular, the addition of SiO2 resulted in the high strength of Si3N4 ceramics. Consequently, it was found that Si3N4 and SiO2 particles played the role of diluents, and SiO2 was effective in post-reaction sintering as an oxygen donor.

A novel aerogels/porous Si3N4 ceramics composite with high strength and improved thermal insulation property

2018 ◽  
Vol 44 (5) ◽  
pp. 5233-5237 ◽  
Author(s):  
Yongqiang Sun ◽  
Zhihao Zhao ◽  
Xiaolei Li ◽  
Hangyuan Zhao ◽  
Zhipeng Hu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
High Strength ◽  
Insulation Property ◽  
Porous Si3n4 ◽  
Thermal Insulation Property ◽  
Si3n4 Ceramics ◽  
Porous Si3n4 Ceramics

Decomposition of the metastable beta titanium alloy Ti-15-3

1983 ◽  
Vol 41 ◽  
pp. 264-265
Author(s):  
Y. L. Chen ◽  
S. Fujlshiro
Keyword(s):  
Low Cost ◽  
High Strength ◽  
Alpha Phase ◽  
Thick Sheet ◽  
Omega Phase ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Beta Matrix ◽  
Metastable Beta ◽  
Very High

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

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