Phase Formation, Microstructures and Mechanical Properties of Lead-Free BNKT Ferroelectric Ceramics Doped with BZZ

2016 ◽  
Vol 675-676 ◽  
pp. 589-592 ◽  
Author(s):  
Chatchai Kruae-In ◽  
Paponsan Puanpia ◽  
Orawan Takhan ◽  
Suchittra Inthong
Keyword(s):  
Mechanical Properties ◽  
Phase Formation ◽  
Xrd Analysis ◽  
Ferroelectric Ceramics ◽  
Sodium Potassium ◽  
Hardness Tester ◽  
Average Grain Size ◽  
All Ceramic ◽  
Pure Phase ◽  
Bismuth Sodium Potassium Titanate

In this research, the effects of bismuth zinc zirconate (BZZ) additive on phase formation, microstructural and mechanical properties of bismuth sodium potassium titanate (BNKT) ceramics were investigated. The BZZ-doped BNKT ceramics were prepared using solid state reaction technique. The pure phase of BZZ-doped BNKT powders were achieved for a calcinations temperature of 850 °C for 4h. The obtained powders were pressed into small pellets and sintered at optimum temperature to from dense ceramics. The XRD analysis of the ceramics shows that all ceramic samples exhibited a pure phase perovskite structure. The bulk densities of samples were about 5.82-6.03 g/cm3 which measured using the Archimedes method. The mechanical properties were measured using micro hardness tester. The microstructural of sintered surface was investigated using scanning electron microscopy (SEM). Average grain size increased with increasing BZZ content. The relations of these results were discussed and compared to the previous works.

Study on High Pressure Sintering of Nanocrystalline Diamond with Nano Silicon as Additives

2016 ◽  
Vol 848 ◽  
pp. 613-617
Author(s):  
Fu Ming Deng ◽  
Chang Zhan ◽  
Ye Zhao ◽  
Wen Li Deng ◽  
Qing Lei
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Performance ◽  
Nanocrystalline Diamond ◽  
Hardness Tester ◽  
Sintering Time ◽  
Wear Ratio ◽  
Average Grain Size ◽  
High Pressure Sintering ◽  
Surface Graphitization

In this paper, nanocrystalline diamond with the average grain size of 50nm was prepared under different sintering pressure, temperature and sintering time. The microstructure of the sample was analyzed by SEM, EDS and XRD, and the mechanical properties tested by micro-hardness tester and wear ratio instrument. The results show that the sample sintered under the optimum conditions of oil pressure 87MPa, heating power 4000W and sintering time 120s possessed hardness of 706.41HV and wear ratio of 3280. It indicated that high performance n-PCD sintered from nanodiamond and silicon system can be formed hardly with diamond to diamond bonding but can be formed with diamond to silicon carbide bonding. The poor mechanical properties of the samples were due to the surface adsorption groups and surface graphitization of nanodiamond during high pressure sintering.

Assessment of Mechanical Properties and Transformation Behavior of Locally-Made Ni-Ti Alloys Used in Orthodontics

2008 ◽  
Vol 55-57 ◽  
pp. 245-248 ◽  
Author(s):  
Nattiree Chiranavanit ◽  
Anak Khantachawana ◽  
N. Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Testing Machine ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Bending Test ◽  
Hardness Tester ◽  
Ti Alloys ◽  
Heat Treated ◽  
Average Grain Size

Ni-Ti alloy wires have been widely used in clinical orthodontics because of their properties of superelasticity (SE) and shape memory effect (SME). The purpose of this study was to assess the mechanical properties and phase transformation of 50.7Ni-49.3 Ti (at%) alloy (NT) and 45.2Ni-49.8Ti-5.0Cu (at%) alloy (NTC), cold-rolled with various percent reductions. To investigate SE and SME, heat-treatment was performed at 400°C and 600°C for 1 h. The specimens were examined using an Energy-Dispersive X-ray Spectroscope (EDS), Differential Scanning Calorimeter (DSC), Universal Testing Machine (Instron), Vickers Hardness Tester and Optical Microscope (OM). On the three-point bending test, the superelastic load-deflection curve was seen in NTC heat-treated at 400°C. Furthermore, NT heat-treated at 400°C with 30% reduction produced a partial superelastic curve. For SME, no conditions revealed superelasticity at the oral temperature. Micro-hardness value increased with greater percentage reduction. The average grain size for all specimens was typically 55-80 µm. The results showed that locally-made Ni-Ti alloys have various transformation behaviors and mechanical properties depending on three principal factors: chemical composition, work-hardening (the percent reduction) and heat-treatment temperature.

scholarly journals COMPREHENSIVE INVESTIGATION OF PHASE FORMATION MECHANISM AND PHYSICO-MECHANICAL PROPERTIES OF Ca-Mg-SILICATE

2021 ◽  
Vol 11 (2) ◽  
pp. 37-50
Author(s):  
Myat Myat-Htun ◽  
Hossein Mohammadi ◽  
Ahmad-Fauzi Mohd Noor ◽  
Masakazu Kawashita ◽  
Yanny Marliana Baba Ismail
Keyword(s):  
Mechanical Properties ◽  
Phase Formation ◽  
Formation Mechanism ◽  
Heat Treating ◽  
Xrd Analysis ◽  
High Energy ◽  
X Ray Diffraction ◽  
Phase Development ◽  
Milling Method ◽  
Phase Formation Mechanism

This study aimed to investigate extensively the full phase formation mechanism from the lowest temperature to form the phases to the optimum temperature to crystallize akermanite. The effects of various milling speeds and sintering temperatures on physico-mechanical properties of akermanite prepared using high-energy planetary milling method were also investigated. The minimum formation temperature of akermanite phase (above 800°C) was determined by X-Ray diffraction (XRD) and differential thermal analysis. XRD analysis revealed akermanite had formed through gradual phase development with the increase in temperature. Below 700C, akermanite was structurally unstable while multiple transient compounds (low clinoenstatite, wollastonite, monticellite, and diopside) coexisted, as indicated by low peak intensities. Single phase akermanite was obtained by heat-treating at 1100C. Physical studies suggested the densest akermanite ceramic feature, with tensile strength range of 25.26 ± 1.41 MPa32.10 ± 2.13 MPa and Vickers microhardness range of 1.39 ± 0.04 GPa4.94 ± 0.26 GPa could be obtained at 1250°C.

Superplastic Sinter-Forging of Fine-Grained Si3N4-Si2N2O Composite at Low Temperature

2007 ◽  
Vol 551-552 ◽  
pp. 487-490 ◽  
Author(s):  
Jun Ting Luo ◽  
Qing Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Complex Shape ◽  
Sintering Temperature ◽  
Xrd Analysis ◽  
Liquid Phase Sintering ◽  
Sintered Body ◽  
Fine Grained ◽  
Sinter Forging ◽  
Average Grain Size

The Si3N4- Si2N2O composites are fabricated with amorphous nano-sized silicon nitride powders by the liquid phase sintering (LPS) method. XRD analysis shows sintered body consists of β-Si3N4 and Si2N2O. SEM experiment conforms that the average grain size of sintered body is less than 300nm. The complex-shape gears can be formed by a sinter-forging technology when the sintering temperature is 1600°C and the superplastic forging temperature is only 1550°C. Rod-shaped grains aligned along the perpendicular direction of pressure and the mechanical properties increase about 10% after the materials were forged.

scholarly journals Preparation and Tribocorrosion Performance of Different Si-Doped TiSiN-Ag Coatings on Different Substrates in Seawater

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 459
Author(s):  
Ke Cai ◽  
Bailing Jiang ◽  
Jing Zhang ◽  
Xiaolei Su
Keyword(s):  
Mechanical Properties ◽  
Friction And Wear ◽  
Composite Coatings ◽  
Doping Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Si Doping ◽  
Average Grain Size ◽  
Si Doped

TiSiN-Ag composite coatings with different Si doping contents were prepared by multi-arc ion plating technology on 316L, TC4, and H65 copper substrates, respectively. The microstructure of the prepared coatings was characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy, respectively. The mechanical properties, electrochemical properties, and tribological properties were characterized by a micro-hardness tester, electrochemical workstation, scratch tester, and friction and wear tester, respectively. Results showed that the coatings with 8 wt.% Si doping content had a smaller average grain size, denser structure, excellent mechanical properties, and better anti-tribocorrosion performance than those with 5 wt.% Si doping content. The coating on the TC4 substrate with 8 wt.% Si doping content presented the best combination of properties and is a candidate for an anti-tribocorrosion material in seawater.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

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