Study on the Heat–Treatment Reinforcement of Aluminum Nitride–Silicon Carbide Composites

1993 ◽  
Vol 327 ◽  
Author(s):  
Li Ningfang ◽  
Zhang Hongquan ◽  
Wang Guomei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Silicon Carbide ◽  
Phase Composition ◽  
High Temperature ◽  
Grain Boundary ◽  
Aluminum Nitride ◽  
Phase Structure ◽  
Glass Phase ◽  
Boundary Phase

AbstractThe effects of heat – treatment on the mechanical properties of AIN – SiC whisker composites with Y2O3 and SiO2 additives has been studied. When the sample containing 10 wt% Y2O3 +SiO2 (Y2O3/SiO2= 1/0. 66) was treated at 1300°C in air for 140 hours the strength of compositqs was raised from 481 MPa to 784 MPa.The phase composition, microstructure and grain boundary phase structure have been characterized by combining XRD, SEM, TEM/EDXA and HREM techniques. The reinforcement mechanism of the composites results from crystallization of the glass phase in the grain boundary at the high temperature oxidizing atmosphere to form the crossing structure of 2Hδ Sialon fibrous phase and SiC whisker.

scholarly journals Ageing of Zirconia Dedicated to Dental Prostheses for Bruxers Part 2: Influence of Heat Treatment for Surface Morphology, Phase Composition and Mechanical Properties

2019 ◽  
Vol 58 (1) ◽  
pp. 218-225
Author(s):  
Damian S. Nakonieczny ◽  
Agata Sambok ◽  
Magdalena Antonowicz ◽  
Marcin Basiaga ◽  
Zbigniew K. Paszenda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
High Temperature ◽  
Surface Morphology ◽  
Aging Process ◽  
Negative Impact ◽  
Bending Test ◽  
High Temperature Heat Treatment ◽  
Dental Prostheses

Abstract Purpose: This part of the study focuses on the influence of zirconia heat treatment for surface morphology, phase composition and mechanical properties Methods: Zirconia samples was prepared with ISO 13356:2013 and ISO 14704:2008 recommendations. X-ray diffraction, observations (SEM) and (AFM), microhardness (Olivera & Phara method), and static bending test (4PBT) were taken. Results: characterization of YSZ and high temperature heat treatment has clearly shown that the aging process influences the change in phase composition of the material, significantly worsening the topography. In turn, re-treatment of the high temperature made after the artificial aging process results in reverse transformation of the desired tetragonal phase, but does not affect the improvement of surface morphology. Conclusions: The research made it possible to assess the negative impact of the zirconium oxide aging simulation process. Because of the failure to achieve the intended results, it was also proved that the high-temperature re-processing was not appropriate.

Process Dependence of Microstructure and Properties of Sintered Aluminum Nitride for Electronic Packaging

1992 ◽  
Vol 264 ◽  
Author(s):  
I. Dutta ◽  
S. Mitra ◽  
J. Cooper
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Nitride ◽  
Treatment Condition ◽  
Heat Treatment Condition ◽  
Boundary Phase ◽  
Secondary Phases ◽  
Treatment Conditions ◽  
Sintered Aluminum ◽  
Sintered Product

AbstractThe development of secondary phases due to additions of Y2O3 during sintering of aluminum nitride was studied. Depending on the heat treatment conditions and the amount of Y2O3 added, different proportions of AlYO3, Al5Y3O12 and Al2Y4O9 were found at the grain boundaries. Temperatures ≳1850°C also resulted in loss of Y2O3 and/or Y-aluminate, yielding some γAl2O3. The mechanical properties and the thermal conductivity of the sintered product were observed to be dependent on the grain boundary phase constitution and hence the specific heat treatment condition.

Solid State Sintering of SiC-Ceramics

2009 ◽  
Vol 624 ◽  
pp. 71-89 ◽  
Author(s):  
Koushik Biswas
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
High Temperature ◽  
Solid State ◽  
Grain Boundary ◽  
Hot Pressing ◽  
Amorphous Film ◽  
Structure Property ◽  
Secondary Phases ◽  
Sintering Aid

The most interesting feature in silicon carbide is the structure-property relation where the formation of different types of microstructure due to different structural modifications (polytypism) and grain-boundary/interfacial phase chemistry dictate the final properties of the monoliths. Since synthesis of SiC in last century, several methods such as hot pressing with a sintering aid (B, C), pressureless sintering with a sintering aid (B, C, Al) and reaction bonded (Si-SiC) were used to fabricate dense SiC. A newer method of fast sintering (spark plasma sintering) using pulsed current is also employed to consolidate nano/submicron size SiC with or without additives. The solid state sintered SiC materials have fine-grained equiaxed microstructure (grain size 1 to 4 µm) with thin layer of intergranular phases (amorphous film), exhibit moderate high-temperature creep and oxidation resistance, fracture toughness (3 to 4 MPam1/2) and have highly flaw-sensitive strength at room temperature. The high temperature mechanical properties are highly influenced by the presence of free C, Al and B + C containing grain-boundary phases. Moreover, during prolong processing, abnormal grain growth occurs resulting in anisotropic -SiC phase formation. The Si-SiC materials are poor candidates for high-temperature applications due to the limit set by the melting point of silicon, and the limitations of hot pressing (HPSiC) as a densification technique are well known. SPSed SiC without sintering additive revealed inferior mechanical properties attributed to poor bonding between adjacent grains. In the present survey, an overview of the new developments in silicon carbide processing and properties will be presented together with the information on structure-properties correlationship. Information on the structure of the grain-boundary/secondary phases and interfaces until now was not comprehensively analyzed.

Grain Boundary Microstructure of a Hot Isostatically Pressed Silicon Nitride

1997 ◽  
Vol 3 (S2) ◽  
pp. 731-732
Author(s):  
L. Fu ◽  
M. J. Hoffmann ◽  
X. Pan
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Chemical Composition ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Phase ◽  
Sintering Aids ◽  
Size And Morphology ◽  
Boundary Microstructure

Si3N4-based materials exhibit attractive mechanical properties for high-temperature applications. These properties are influenced strongly by the size and morphology of the grain boundaries and grain-boundary phase. An amorphous intergranular film (IGF) commonly exists at two grain junctions. The thickness of these IGFs sensitively depend on the chemical composition of the intergranular phase.In this work, our studies on the grain boundary microstructure of Si3N44 ceramics made by Hot Isostatically Pressing (HIPing).Si3N44 materials were densified by HIPing Si3N4 powders (UBE E-10) at 1950°C at 200 MPa for 1 hour, with sintering aids of either Y2O3 or Y2O3 + A12O3. Two materials were made: material A consisting of 2 wt% Y2O3; material B consisting of 5 wt% Y2O3 and 1 wt% A12O3. Both as-HIPed and oxided samples were investigated. TEM specimens were prepared by conventional procedures. The microstructure and chemical composition were studied on a JEOL 2000FX.

Study on Microstructure and Mechanical Properties of Mg9AlZnGdY Magnesium Alloy after T6 in Lost Foam Casting

2011 ◽  
Vol 291-294 ◽  
pp. 565-568
Author(s):  
Zhong Zhao ◽  
Qiang Luo ◽  
Zi Tian Fan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Grain Boundary ◽  
Lost Foam Casting ◽  
High Temperature Strength ◽  
T6 Heat Treatment ◽  
Lost Foam

The microstructures and mechanical properties of Mg9AlZnGdY alloy after T6 heat treatment in lost foam casting (LFC) are compared with that of AZ91D magnesium alloy. The results show that the microstructures of Mg9AlZnGdY alloy after T6 heat treatment consist of the α-Mg solid solution, β-Mg17Al12 precipitation phase, a small amount of rod Al2Y and block Al2Gd phases, which are distributed over grain boundaries of the α-Mg phase. The thermal stability of Al2Y and Al2Gd phases offers the pinning effect on the grain boundary under high temperature, and therefore, the grain boundary sliding is eliminated and the high-temperature strength is increased. After the T6 heat treatment, the tensile strength of Mg9AlZnGdY alloy was 235MPa at room temperature, and 156MPa at 200°C. Compared with that of AZ91D alloy, the tensile strength was increased by 19.3% and 38.1% respectively.

ALUMINUM 319.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Rear Axle ◽  
Heat Treating ◽  
General Purpose ◽  
Temperature Performance

Abstract ALUMINUM 319.0 is a general-purpose foundry alloy that is moderately responsive to heat treatment. It has excellent casting characteristics and good mechanical properties. Among its many uses are crankcases, housings, engine parts, typewriter frames and rear-axle housings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as creep and fatigue. It also includes information on low and high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-256. Producer or source: Various aluminum companies.

Microstructure and Mechanical Properties of Ti-6Al-4V Manufactured by SLM

2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Behavior ◽  
Ductile Fracture ◽  
Elevated Temperatures ◽  
Initial Material ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.

The Effect of Heat Treatment on Mechanical Properties of Car Interior Fabric Used for Injection Molding

2012 ◽  
Vol 532-533 ◽  
pp. 234-237
Author(s):  
Wei Lai Chen ◽  
Ding Hong Yi ◽  
Jian Fu Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Injection Molding ◽  
High Temperatures ◽  
Material Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Composite Fabrics

The purpose of this paper is to study the effect of high temperature in injection molding process on mechanical properties of the warp-knitted and nonwoven composite fabrics (WNC)used in car interior. Tensile, tearing and peeling properties of WNC fabrics were tested after heat treatment under120, 140,160,180°C respectively. It was found that, after 140°C heat treatment, the breaking and tearing value of these WNC fabrics are lower than others. The results of this study show that this phenomenon is due to the material properties of fabrics. These high temperatures have no much effect on peeling properties of these WNC fabrics. It is concluded that in order to preserve the mechanical properties of these WNC fabrics, the temperature near 140°C should be avoided possibly during injection molding process.

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