scholarly journals Study on process development and property evaluation of sol-gel derived magnesia stabilized zirconia minispheres

2014 ◽  
Vol 32 (2) ◽  
pp. 145-156 ◽  
Author(s):  
J. Judes ◽  
V. Kamaraj
Keyword(s):  
Mechanical Properties ◽  
Process Development ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Processing Parameters ◽  
Processing Technique ◽  
Density Variation ◽  
Phase Identification ◽  
Stabilized Zirconia ◽  
Grinding Media

AbstractIn order to overcome limitations in the processing parameters of powder compaction method, a novel processing technique based on sol-gel route has been developed to produce near-net-shaped prototype fine zirconia minispheres with required properties that could potentially be used as grinding media. Impact of magnesia concentration and sintering temperature on the final product has been analyzed in detail. Zirconia minispheres have been characterized to establish a correlation between physical, structural and mechanical properties. Sintering temperature, soaking period, heating rate and viscosity of the sol apparently influence the characteristics of the magnesia stabilized zirconia minispheres. The phase identification, density variation, chemical decomposition, functional group specification, surface area, porosity, shrinkage and microstructural features of the dried and sintered final product have been studied. It has been observed that magnesia content, sintering temperature, density and the grain size of the sintered minispheres have a significant impact on the mechanical properties of the final product.

Effect of Processing Parameters on Mechanical Properties of Al7175/Boron Carbide (B4C) Composite Fabricated by Powder Metallurgy Techniques

2021 ◽  
Vol 105 ◽  
pp. 8-16
Author(s):  
Guttikonda Manohar ◽  
Krishna Murari Pandey ◽  
Saikat Ranjan Maity
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Matrix Composites ◽  
Composite Powders ◽  
Porosity Level ◽  
Milling Operations ◽  
Boron Carbide B4c

Metal matrix composites attain a significant position in Industrial, defense, structural and automobile applications. To amplify that strategy there is a need to find out the conditional behavior of the composites and enhancing the properties will be mandatory. The present work mainly investigates on the effect of processing parameters like densification rates, sintering temperature, reinforcement content on the microstructure, mechanical properties of the Al7175/B4C composite material fabricated by mechanical milling and powder metallurgy techniques. Results show there is a grain size reduction and refinement in the composite material through ball milling operations and along with that increasing B4C content in the composite powders make milling conditions very effective. Increasing the sintering temperature results in a consistent grain growth along with that porosity level decreases up to a limit and then attain a steady state, the strength of the composites increases with compaction pressures but reinforcements content effects the strength of the material by losing its ductility making it brittle.

scholarly journals Evaluation of Phase Transformation and Mechanical Properties of Metastable Yttria-Stabilized Zirconia by Nanoindentation

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1677 ◽  
Author(s):  
Ningning Song ◽  
Ziyuan Wang ◽  
Yan Xing ◽  
Mengfei Zhang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Young’S Modulus ◽  
Tetragonal Phase ◽  
Young's Modulus ◽  
Traditional Approach ◽  
Yttria Stabilized Zirconia ◽  
Phase Identification ◽  
Stabilized Zirconia ◽  
T Phase

Microscopical nonuniformity of mechanical properties caused by phase transformation is one of the main reasons for the failure of the materials in engineering applications. Accurate measurement of the mechanical properties of each phase is of virtual importance, in which the traditional approach like Vickers hardness cannot accomplish, due to the large testing range. In this study, nanoindentation is firstly used to analyze the mechanical properties of each phase and demonstrate the phase transformation in thermal barrier coatings during high-temperature aging. The distribution of T-prime metastable tetragonal phase, cubic and tetragonal phase is determined by mapping mode of nanoindentation and confirmed with X-ray diffraction and scanning electron microscope observation. The results show that during 1300 °C aging, the phase transition of metastable Yttria-Stabilized Zirconia induces the quick decrease of T′ phase content and an increase of T and C phases accordingly. It is found that there are some fluctuations in the mechanical properties of individual phase during annealing. The hardness and Young’s modulus of T′ increase at first 9 h, due to the precipitation of Y3+ lean T phase and then decrease to a constant value accompanied by the precipitation of Y3+ rich C phase. The relevant property of C phases also increases a little firstly and then decreases to a constant, due to the homogenization of Y3+ content, while the hardness and Young’s modulus of T phase remain unchanged. After aging of 24h the hardness of T′, C and T phases are 20.5 GPa, 21.3 GPa and 19.1 GPa, respectively. The Young’s modulus of T′, C and T phases are 274 GPa, 275 GPa and 265 GPa, respectively. Present work reveals the availability of nanoindentation method to demonstrate the phase transformation and measure mechanical properties of composites. It also provides an efficient application for single phase identification of ceramics.

scholarly journals The Effect of Yttria-Stabilized Zirconia on the Properties of the Fluorine-Substituted Hydroxyapatite Ceramics Prepared by Pressureless Sintering

2008 ◽  
Vol 1 ◽  
pp. 57-68 ◽  
Author(s):  
Y. Chen ◽  
Z. Dong ◽  
X. Miao
Keyword(s):  
Mechanical Properties ◽  
Thermal Decomposition ◽  
Sol Gel ◽  
Yttria Stabilized Zirconia ◽  
Pressureless Sintering ◽  
Stabilized Zirconia ◽  
Gel Method ◽  
Zirconia Composites ◽  
Zirconia Phase ◽  
Hydroxyapatite Phase

Hydroxyapatite-zirconia composites have received much attention during the last decade due to their combination of the desirable mechanical properties of zirconia and the excellent bioactivity of hydroxyapatite (HA). However, thermal decomposition of the hydroxyapatite phase and reaction between the zirconia phase and the hydroxyapatite phase remain a major problem in the hydroxyapatite-zirconia composites. In this study, thermally stable and fluorine-substituted hydroxyapatite (Ca10(PO4)6(OH)0.8F1.2; coded as HA06F) was prepared by a sol-gel method to replace the hydroxyapatite. Yttria-stabilized zirconia (YTZP) was also prepared by a sol-gel method in order to produce HA06F-YTZP composites with 5, 10, 15, 20, 40, and 60 wt% YTZP by simple and cost-effective pressureless sintering. Thermogravimetric analysis (TGA) and x-ray diffraction (XRD) of the HA06F-YTZP composites showed that the thermal stability of the HA06F matrices could be maintained when the YTZP content did not exceed 20 wt% and for sintering temperatures less than 1400 oC. Dilatometric analysis and microstructural observation revealed that the YTZP phase in the HA06F-YTZP composites retarded the densification of the composites if the zirconia content was over 20 wt%. Electron scanning microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM) of the HA06F-YTZP composites showed that the YTZP second phase had a size in the nanometer scale and the reaction between the HA06F phase and the zirconia phase was suppressed. Mechanical properties including the Knoop hardness, the Young’s modulus, and the fracture toughness of the HA06F-YTZP composites increased with the YTZP content until the optimal content of 20 wt%; higher YTZP contents led to low mechanical properties due to poor densification of the composites and the severe thermal decomposition of the HA06F phase. The optimal HA06F-20YTZP composite also showed desirable attachment and proliferation of osteoblast cells. Nevertheless, the study of the composite system indicated the limitations of the pressureless sintering technique. To achieve the full potential of the composites for medium or low load bearing applications, a pressure-assisted sintering technique would still be necessary.

scholarly journals The Effects of Processing Parameters on the Structure and Mechanical Properties of Structural Pm Steels Containing Mn, Cr and Mo/ Wpływ Parametrów Wytwarzania Na Strukturę I Własności Mechaniczne Spiekanych Stali Konstrukcyjnych Zawierających Mn, Cr I Mo

2014 ◽  
Vol 59 (4) ◽  
pp. 1499-1505 ◽  
Author(s):  
M. Sulowski
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
Surface Hardness ◽  
Processing Parameters ◽  
Mechanical Tests ◽  
Pure Hydrogen ◽  
Low Carbon ◽  
Offset Yield Strength

Abstract The effects of processing parameters on the microstructure and mechanical properties of Fe-Mn-Cr- Mo-C PM steels are described. Pre-alloyed Astaloy CrM and Astaloy CrL, low-carbon ferromanganese and graphite powders were used as the starting materials. After pressing in rigid die, the compacts were conventionally and high temperature sintered at 1120 and 1250°C, respectively. Sintering was carried out for 60 minutes in atmospheres with different H2/N2 ratios. Cooling rate from sintering temperature was 65°C min-1 (convective cooling). The specimens were subsequently tempered at 200°C for 60 minutes in air. All specimens were tested for tensile strength (UTS), elongation (A), offset yield strength (R0:2), transverse rupture strength (TRS), impact toughness and apparent surface hardness (HV 30). After mechanical tests the microstructure of Fe-Mn-Cr-Mo-C PM steels was studied by optical microscopy. These investigations have shown that, by sintering in inexpensive and safe nitrogen-rich atmospheres, it is possible to achieve mechanical properties similar to those of specimens sintered in pure hydrogen and hydrogen-rich atmospheres.

Study on Influencing Factors of Mechanical Properties of Ti(C,N)-Based Cermets

2013 ◽  
Vol 589-590 ◽  
pp. 578-583 ◽  
Author(s):  
Ya Cong Chai ◽  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Hua He Liu
Keyword(s):  
Mechanical Properties ◽  
Energy Dispersive Spectrometry ◽  
Sintering Temperature ◽  
Processing Technique ◽  
Liquid Phase Sintering ◽  
Binder Content ◽  
Powder Size ◽  
Initial Powder ◽  
Sintering Process ◽  
Higher Temperature

Ti(C,N)-based cermets were fabricated by the vacuum hot-processing technique. The effect of sintering process, initial powder size and binder content on mechanical properties of Ti(C,N)-based cermets were investigated. The composite was analyzed by the observation of scanning electron microscope (SEM) and energy dispersive spectrometry (EDS). The results showed that a lower sintering temperature led to insufficient liquid-phase sintering process, which reduced the density of the composite. However, higher temperature and longer holding time resulted in abnormal grain growth, which was not good for improving the mechanical properties of the composite. With the refinement of the initial powder size of the Ti(C,N), the fracture toughness reduced slightly, the flexural strength and Vickers hardness increased. The better mechanical properties were obtained when the binder content of the cermets was designed based on the eutectic composition of Mo-Ni binary alloy phase diagram.

Study of Mechanical Properties of Magnesium Oxide Doped Alumina (Al2O3) and Yttria Stabilized Zirconia (YSZ) Composite for Medical Applications

2012 ◽  
Vol 506 ◽  
pp. 521-524 ◽  
Author(s):  
A. Phothawan ◽  
K. Nganvongpanit ◽  
T. Tunkasiri ◽  
Sukum Eitssayeam
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Magnesium Oxide ◽  
Sintering Temperature ◽  
The Body ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Electron Microscopes ◽  
Pin On Disk ◽  
Scanning Electron Microscopes

The aim of this research is to study the mechanical properties such as hardness ,wear resistance etc , of the magnesium oxide (MgO) doped alumina (Al2O3) and yttria stabilized zirconia (YSZ) composite, We first prepared MgO-doped Al2O3(denoted as Al4) by mixing Al2O3powder and 0.4 wt% of MgO powder. After that Al4powder was mixed YSZ powder, with the formula [(x)Al4- (100-x)YS when x was varied from 0 - 100 by wt%. The samples were sintered at 1450, 1500, 1550, 1600 and 1650 °C. In addition, microstructure of the surface was studied employing both optical and scanning electron microscopes. The hardness of the surface was investigated by Vickers indentation technique and pin on disk apparatus was employed for wear rate measurement. The results showed that the density and volume shrinkage decreased with the increase of Al4content. The grain size and porosity of the specimens tend to decrease when the sintering temperature increases. The hardness and wear resistance of the samples increased with the increase of Al4up to 90 %. It was also found that the material is not toxic to the body.

Fabrication and Mechanical Properties of High-Pure Ti3SiC2 Bulk Materials Directly by Hot-Pressing its Powder

2007 ◽  
Vol 336-338 ◽  
pp. 958-960
Author(s):  
Yang Song ◽  
Chang An Wang ◽  
Chun Qing Peng ◽  
Yong Huang
Keyword(s):  
Mechanical Properties ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Argon Atmosphere ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
Soaking Time ◽  
X Ray ◽  
Microstructure Evaluation

High-pure bulk Ti3SiC2 samples were fabricated by directly hot-pressing (HP) high-pure Ti3SiC2 powder without any additives at 1200°C to 1500°C for 0.5–2 hours in flow argon atmosphere. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used for phase identification and microstructure evaluation. The fabricated Ti3SiC2 materials have relative high density with high purity, flexural strength of 500-700MPa and fracture toughness of 9-12MPa·m1/2. The influence of sintering temperature and soaking time on the mechanical properties of Ti3SiC2 materials was discussed. The sintering mechanism for Ti3SiC2 powder without any additives was considered to be related with the fragile-ductile transformation of Ti3SiC2 at 1100°C.

Enchancement of Mechanical Properties in BaTiO3 Ferroelectric Thin Films

2010 ◽  
Vol 150-151 ◽  
pp. 599-602 ◽  
Author(s):  
Cheng Lu ◽  
Xiang Yun Deng ◽  
Xiao Fen Guan ◽  
Zhong Wen Tan ◽  
Yan Jie Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress ◽  
Elastic Modulus ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Fabrication Method ◽  
Maximum Hardness ◽  
Sol Gel Process

Surface structure and mechanical properties of BaTiO3 thin films prepared by sol-gel process were investigated by XP-2 profiler and nano-indention. The results indicated that the thickness of thin films got thicker with sintering temperature and the thickness-increasing rate differ from different solvent. The hardness and elastic modulus were enhanced due to the presence of residual stress which was compression and probably induced by fabrication method. The maximum hardness is 9.98GPa when the Young’s modulus is 127.41GPa with ethanol as solvent sintered at 1000oC.

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