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

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

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

Reliability Research on Measurement System for Downhole Storage Pressure Gauge

2013 ◽  
Vol 345 ◽  
pp. 516-520
Author(s):  
Heng Wu ◽  
Yong Peng ◽  
Li Ping Wang
Keyword(s):  
Hydraulic Fracturing ◽  
Integrated Circuit ◽  
High Reliability ◽  
Pressure Gauge ◽  
High Strength ◽  
Vibration Resistance ◽  
Logic Diagram ◽  
In Series ◽  
Working Principle ◽  
Mean Time

Downhole storage pressure gauge should meet the requirements of high strength, high temperature resistance, vibration resistance, and high reliability when hydraulic fracturing. Downhole storage pressure gauge has been designed. Based on the working principle, the logic diagram for reliable analysis has been built, which has been connected by five units in series. With the modules of electronic component and integrated circuit, the operating failure rates of the five units have been calculated. The reliability and Mean Time Between Failure of downhole storage pressure gauge have been obtained. The high reliability of the downhole storage pressure gauge can satisfy the measuring demand for pressure and temperature when hydraulic fracturing.

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

Thermal reliability of SiC device with Cu sintering die-attach processed at 250°C in N2 gas

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000193-000196
Author(s):  
Shijo Nagao ◽  
Hiroki Yoshikawa ◽  
Hirofumi Fujita ◽  
Akio Shimoyama ◽  
Shinya Seki ◽  
...  
Keyword(s):  
High Reliability ◽  
High Strength ◽  
Life Time ◽  
Industrial Applications ◽  
Junction Temperature ◽  
Thermal Reliability ◽  
Excellent Thermal Stability ◽  
Power Semiconductors ◽  
Die Attach ◽  
Micron Particle

Abstract Thermostable die-attach method alternative to soldering with Pb content is urgently required for utilizing wide-bandgap power semiconductors like SiC or GaN with a high maximum junction temperature TJ. Ag nano-or micro particle paste sintering attracts wide attention for this purpose, but Cu paste has also being developed mainly because of the cost pressure. Recently Cu sub-micron particle paste dispersed polyethylene Glycol solvent has demonstrated low temperature sintering at 250°C in N2 gas, resulting in high strength of die-attach. In the present study, the developed Cu paste die-attach has accepted to SiC Schottky barrier diode in TO-247 standard packaging with highly thermostable mold materials. The produced sample devices are subjected to high temperature storage tests at 250°C and thermal cycling tests between −50°C and 250°C. The device including the novel die-attach structure exhibited excellent thermal stability. Furthermore, power cycling tests has been conducted, and the results appear prospective for long life time and high reliability with high TJ exceeding 250°C. The presented study thus conclude that Cu submicron paste sintering is a promising candidate of power device die-attach usable for heavy industrial applications.

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

Microtexture and Electrical and Mechanical Properties of the Cold-Sprayed Copper Deposit

2013 ◽  
Author(s):  
Yusuke Watanabe ◽  
Yuji Ichikawa ◽  
Kazuhiro Ogawa ◽  
Hideo Miura
Keyword(s):  
Fine Particles ◽  
High Reliability ◽  
Diffraction Method ◽  
High Strength ◽  
Copper Deposit ◽  
Dielectric Materials ◽  
Electron Back Scatter Diffraction ◽  
Solid Particles ◽  
Electrically Conductive ◽  
Mechanical And Electrical Properties

Cold-spray (CS) technique is a new coating technology that is based on the high-velocity impinging of small solid particles on a substrate. The CS technique can make a thick deposit with less heat influence. Recently, this CS technique has been applied to the formation of an electrically conductive copper layer on dielectric materials such as polymers or ceramics. Previous researches show that the deposits made by the CS technique have high strength and residual stress comparing with bulk copper. However, since the deposits show brittle fracture and cracks propagate along the interfaces of the deposited particles, the deposits can not be applied to the products for which high reliability is indispensable. Therefore, it is very important to clarify the dominant factors which change the crystallinity of the deposits comparing with that of bulk copper in order to improve the quality of the deposits. One of the important factors should be the integrity of the interfaces between the deposited fine particles. This study is to evaluate the micro-texture and physical properties of the cold-sprayed copper deposit. Electron back-scatter diffraction method was applied to the evaluation of the crystallinity of the deposits. In addition, the relationship between the crystallinity with both mechanical and electrical properties of the deposits was clarified quantitatively.

Surface Roughness Research in Turning of Damage-Tolerant Titanium Alloy

2014 ◽  
Vol 633-634 ◽  
pp. 743-746
Author(s):  
Tao Sun ◽  
Zhuo Chen
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Predictive Model ◽  
High Reliability ◽  
Orthogonal Experiment ◽  
High Strength ◽  
Test Results ◽  
Urgent Problem ◽  
Damage Tolerant

TC21 is a first high strength and damage-tolerant titanium alloy self-developed in China, which has independent intellectual property. As it is known to all, titanium alloy TC21 is one of the most widely used materials in aerospace. The improvement of cutting quality of titanium alloy is an urgent problem. In this paper, the orthogonal experiment were carried out to study surface roughness of turning TC21. The predictive model of surface roughness in turning TC21 was built by analysis of multivariable linear regression on the basis of experiment. Statistical test results indicated the established predictive model were in highly notable test status and had high reliability. These works provide references for machining TC21.

The Load Factor and Permanent Set at the Bearing Surfaces in Hollow Cylindrical Bolted Joints Under External Axial Loads

2011 ◽  
Author(s):  
Yukio Morozumi ◽  
Masahiko Okumura ◽  
Toshiyuki Sawa ◽  
Kengo Kuwaki
Keyword(s):  
Contact Stress ◽  
High Reliability ◽  
Fem Analysis ◽  
High Strength ◽  
Theory Of Elasticity ◽  
Bolted Joints ◽  
Load Factor ◽  
Axial Forces ◽  
Bolt Preload ◽  
Plastic Displacement

High strength bolts are utilized widely for high reliability and to reduce the weight of the bolted joints. The usage of the high strength bolts may increase the contact stress at the bearing surfaces. When a bolted joint is under external axial load W, the axial bolt force increases by Ft and the contact stress increases at the bearing surface. This may cause the plastic deformation and a decrease in the axial bolt force. Consequently, it is important to determine the initial axial bolt force (bolt preload) considering external load. In this paper, (load factor) Φ = (Ft/W) is investigated by axi-symmetrical theory of elasticity, FEM analysis and experiments. The results obtained from these methods showed in a fairly good agreement. Then the contact stress distributions and the plastic displacement distributions under external loads were studied for three different initial axial forces by elasto-plastic FEM analyses. The prediction for the reduction in axial bolt force, which is obtained by multiplying the setting factor by the mean plastic displacement, was compared with the experiment. As a result, it was found that a higher bolt preload shows a small reduction in axial bolt force.

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