Revealing the real high temperature performance and depolarization characteristics of piezoelectric ceramics by combined in situ techniques

2018 ◽  
Vol 6 (6) ◽  
pp. 1433-1444 ◽  
Author(s):  
Chengcheng Huang ◽  
Kai Cai ◽  
Yingcong Wang ◽  
Yang Bai ◽  
Dong Guo
Keyword(s):  
High Temperature ◽  
Thermal Cycle ◽  
Piezoelectric Ceramics ◽  
Depolarization Temperature ◽  
The Real ◽  
In Situ Techniques ◽  
Temperature Performance ◽  
Polarization Variation

Polarization variation in a thermal cycle and in situ HT d33 revealed real depolarization temperature and distinct d33 recovery.

Sialons and Silicon Nitrides; Microstructural Design and Performance

1992 ◽  
Vol 287 ◽  
Author(s):  
M.H. Lewis
Keyword(s):  
High Temperature ◽  
Thermal Cycle ◽  
Dispersed Phase ◽  
Silicon Nitrides ◽  
Metal Compounds ◽  
Temperature Regimes ◽  
Temperature Capability ◽  
Microstructural Design ◽  
And Performance

ABSTRACTsurvey is presented of developments in silicon nitride and sialon ceramic microstructures designed for application in differing temperature regimes.For low temperature (< 1000°C) application, pressureless-sinterable sialons with moderate (10-15%) intergranular glass, anisotropic β′ grains and high values of MOR and Kc (1 GPa and 6-10MPa| m respectively) are preferred.Improved hardness and high temperature capability may be achieved by tailoring intergranularp hases for crystallisation and further enhanced by the introduction of mixed α′/β′ Sialon microstructures. Examples are given of microstructural evolution in β′- Y3Al5O12(garnet), β′-Nd3Si3Al3O12N2 and α′/β′/garnet ceramics and a comparison of their mechanical behaviour.Novel Sialon ceramics containing dispersed transition metal compounds (TiN, TiB2) may be formed by in-situ redox reaction, utilising the α′ Sialon phase as an oxygen receptor. The dispersed phase may enhance hardness and toughness and confer electro-discharge machinability.Oxidation instability of Sialon compositions dictates the use of diphasic Si3N4/M2Si2O7 microstructures for application above 1300°C. The thermal cycle during pressurised sintering of these non-sialon compositions is critical in avoiding crystallisation of mixed polymorphs of the intergranular disilicate, with consequent microcracking.

Synthesis In Situ Composite TiAl-Based with Particulate Al2O3 Reinforcement by Powder Metallurgy Route

2013 ◽  
Vol 858 ◽  
pp. 159-163
Author(s):  
Tran Duc Huy ◽  
Nguyen Hong Hai ◽  
Keiichi N. Ishihihara
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Matrix Material ◽  
High Temperature Strength ◽  
Market Place ◽  
In Situ Techniques ◽  
Specific Strength ◽  
Reaction Characteristic ◽  
Selection Of

A major effort has been made over last 20 or so years to introduce TiAl-based alloys into the market-place as engineering component. Recently, titanium aluminide based composites are competitive candidate for aerospace use due to the favorable properties of matrix material, such as low density, high specific strength and relative good properties at elevate temperature [1-4]. The amount of aluminum in titanium alloys exceeds that used in conventional alloys and can range from 10 to 48at%. This concentration of aluminum allows the formation of anin-situalumina reinforcement which is responsible for the excellent oxidation, sulfidation and carburization resistance at temperatures of 1000°C and higher. However, their brittleness and rapid crack growth rate at low to intermediate temperature hinders their application/3/. Nevertheless, nanostructure of monolithic TiAl is unstable at elevate temperatures which deteriorate the high temperature properties. In order to improve the high temperature strength of intermetallic, ceramic particles can be utilized as reinforcements [4, 5]. Recently, in-situ techniques have been utilized to fabricate TiAl-Al2O3composite through displacement reaction between TiO2and Al in planetary ball milling and subsequence heat treatment. The knowledge of reaction characteristic in the Al-TiO2system is great importance to optimize the processing/4, 6/. The chemical compatibility with the iron aluminide matrix at temperature above 1000°C is an important factor for the selection of reinforcements because extreme interfacial reaction during processing results in the degradation of mechanical properties [3, 4].

Hydrophobic in-situ SiO2-TiO2 composite aerogel for heavy oil thermal recovery: Synthesis and high temperature performance

2021 ◽  
Vol 190 ◽  
pp. 116745
Author(s):  
Sijia Liu ◽  
Xiaodong Wu ◽  
Yanhan Li ◽  
Sheng Cui ◽  
Xiaodong Shen ◽  
...  
Keyword(s):  
High Temperature ◽  
Heavy Oil ◽  
Thermal Recovery ◽  
Composite Aerogel ◽  
Temperature Performance

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

ALLEGHENY LUDLUM AL276

Alloy Digest ◽  
1996 ◽  
Vol 45 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Power Plant ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Crevice Corrosion ◽  
Heat Treating ◽  
Chemical Plants ◽  
Temperature Performance

Abstract Allegheny Ludlum AL276 is widely used in the most severe environments found in chemical plants and in power plant desulfurization systems. The high molybdenum level with tungsten gives excellent pitting and crevice corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, joining, and surface treatment. Filing Code: Ni-497. Producer or source: Allegheny Ludlum Corporation.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

ALTEMP HX

Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.

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