Microstructure and Mechanical Properties of Sm1-xSrxCo0.2Fe0.8O3

2000 ◽  
Vol 15 (7) ◽  
pp. 1505-1513 ◽  
Author(s):  
Y-S. Chou ◽  
J. W. Stevenson ◽  
T. R. Armstrong ◽  
J. S. Hardy ◽  
K. Hasinska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Indentation Fracture ◽  
Flexure Strength ◽  
Indentation Toughness ◽  
Indentation Fracture Toughness ◽  
Microhardness Indentation ◽  
Biaxial Flexure

The room temperature mechanical properties of a mixed conducting perovskite Sm1?xSrxCo0.2Fe0.8O3 (x = 0.2 to 0.8) were examined. Density, crystal phase, and microstructure were characterized. It was found that the grain size increased abruptly with increasing Sr content. Mechanical properties of elastic modulus, microhardness, indentation fracture toughness, and biaxial flexure strength were measured. Young's modulus of 180–193 GPa and shear modulus of 70–75 GPa were determined. The biaxial flexure strength was found to decrease with increasing Sr content from ∼70 to ∼20 MPa. The drop in strength was due to the occurrence of extensive cracking. Indentation toughness showed a similar trend to the strength in that it decreased with increasing Sr content from ∼1.1 to ∼0.7 MPa m1/2. In addition, fractography was used to characterize the fracture behavior in these materials.

Synthesis and Properties of In-Situ MoSi2/SiC Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
S. Jayashankar ◽  
S.E. Riddle ◽  
M. J. Kaufman
Keyword(s):  
Fracture Toughness ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Indentation Fracture ◽  
Processing Scheme ◽  
Indentation Fracture Toughness ◽  
Novel Processing ◽  
Sic Composites

AbstractCompositionally-tailored, silica-free, MoSi2/SiC composites with SiC content ranging from 0 to 40 percent were synthesized through a novel processing scheme involving mechanical alloying and in-situ reactions for the formation of the reinforcement. Room temperature indentation fracture toughness and hardness measurements were obtained from these silica-free composites and were compared with values obtained from silica-containing, conventionally-processed MoSi2/SiC composites.

Mechanical Characterization of Dense Hydroxyapatite Blocks

2006 ◽  
Vol 514-516 ◽  
pp. 1083-1086
Author(s):  
Cláudia M.S. Ranito ◽  
Fernando A. Costa Oliveira ◽  
João P. Borges
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Full Density ◽  
Indentation Fracture ◽  
Mechanical Characterisation ◽  
Indentation Fracture Toughness ◽  
Ft Ir

Bioactive dense HAp ceramics possess a unique set of properties, which make them suitable as bone substitute. However, both physical and mechanical properties of HAp have to be evaluated in order to produce new materials that match the bone stiffness. This paper highlights the influence of both porosity and grain size on the four-point flexural strength and the indentation fracture toughness of pure dense HAp blocks sintered at 1300°C. Both discs and rectangular bars were produced by uniaxial pressing at 40MPa and sintered in static air at temperatures between 1150 and 1325°C for 1 h in order to assess the densification behaviour of the P120S medical grade HAp powder used. After sintering, both the density and the open porosity were measured. In addition to FT-IR, XRD and SEM, the mechanical properties of the dense HAp blocks, including Young´s modulus, flexural strength, Vicker´s hardness and fracture toughness, were characterized and whenever possible these properties were compared to those reported for cortical bone. Pressureless sintering to full density at temperatures below 1300°C does not occur for the stoichiometric powder used. The results obtained underline the importance of full mechanical characterisation of dense HAp so that new implant materials can be developed. There is a need to improve the microstructure and thus enhance mechanical strength of HAp ceramics, as it was found that flexural strength is closely related to the micropores present in the sintered samples.

Preparation and Mechanical Properties of ReAl11O18 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 345-348
Author(s):  
Jun Dong Zhang ◽  
Ming Hao Fang ◽  
Zhao Hui Huang ◽  
Yan Gai Liu ◽  
Xin Min ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Bulk Density ◽  
Room Temperature ◽  
Pressureless Sintering ◽  
Optimal Temperature ◽  
Flexure Strength ◽  
The Real

In this paper, plate-like ReAl11O18 (Re = La, Pr, Nd) toughened ceramics were prepared by pressureless sintering at 1650 °C for 5 h in air. The bulk densities of the sintered samples were between 4.7 to 5.3g/cm3. The mechanical properties of the ReAl11O18 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ReAl11O18 ceramics were 97.5 to 102.7 Mpa and 3.8 to 4.2Mpa.m1/2. The results show that: The optimal temperature to synthesis ReAl11O18 ceramics was 1650 °C; The flexural strength and fracture toughness of the ReAl11O18 ceramics increase with the increasing of its bulk density.

Mechanical Properties of ZrO2–LaMgAl11O19 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 455-458 ◽  
Author(s):  
Xin Min ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Zhao Hui Huang ◽  
Feng Jiao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Transformation Toughening ◽  
Flexure Strength ◽  
Phase Transformation Toughening ◽  
Physical And Chemical ◽  
And Chemical Properties

ZrO2 ceramics have been widely used to many fields with its excellent physical and chemical properties, but the mechanical properties of YSZ ceramics, especially the fracture toughness, decline caused by the failure of the phase transformation toughening at high temperature. In this investigation, plate-like LaMgAl11O19 toughened ZrO2 ceramics were prepared by pressureless sintering at 1550 °C for 3h in air . The bulk density of the sintered samples are between 5.5 to 6.0 g/cm3, and the relative density are above 93%. The mechanical properties of the ZrO2-LaMgAl11O19 ceramics were studied systematically at room temperature. The flexure strength and fracture toughness of ZrO2-LaMgAl11O19 ceramic are 811.8 MPa and 13.9 MPa•m½ with the LMA addition of 2wt%.

Comparison of R-Curve Behavior of Si3N4 Measured by Indentation Method and Single-Edge V-Notched Beam Technique (SEVNB)

2009 ◽  
Vol 409 ◽  
pp. 308-312
Author(s):  
Jana Špaková ◽  
Ján Dusza
Keyword(s):  
Fracture Toughness ◽  
Crack Opening ◽  
Single Edge ◽  
Indentation Fracture ◽  
Indentation Method ◽  
Indentation Toughness ◽  
Indentation Fracture Toughness ◽  
Beam Technique

Study compare R-curve behaviour of silicon nitride obtained using Vickers indented beam specimens and single edge V-notched beam (SEVNB). R-curve measurement realized by Vickers indented beam was reported by Krause. Crack growth using single edge V-notched beam was observed in situ. The indentation experiments, in comparison with SEVNB method revealed higher R-curve values (KR=3.3 – 4.8 MPa.m1/2). The discrepancy in the R-curve results is attributed to inaccuracy related to the determination of indentation toughness. The indentation fracture toughness may include the aspects of crack opening behaviour, residual indentation stress intensity.

scholarly journals Analyzing Time on Sample During Nanoindentation

2016 ◽  
Vol 13 (2) ◽  
pp. 74-79 ◽  
Author(s):  
A. S. Bhattacharyya ◽  
P Kumar ◽  
N Rajak ◽  
R.P Kumar ◽  
A Sharma ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Significant Contribution ◽  
Substrate Effect ◽  
Failure Zone ◽  
Indentation Fracture ◽  
Depth Sensing ◽  
Indentation Fracture Toughness ◽  
Depth Curves

Nanoindentation is an effective way of finding mechanical properties at nanoscale. They are especially useful for thin films where elimination of the substrate effect is required. The mechanism is based upon depth sensing indentation based on Oliver and Pharr modeling. The load-depth curves as well as time on sample were analyzed. Indentation impulse was found to have significant contribution in the nature of failure zone during indentation. Fracture toughness was also related to time on the sample.

scholarly journals Microwave Sintering of SiAlON Ceramics with TiN Addition

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1345 ◽  
Author(s):  
Özgür Sevgi Canarslan ◽  
Roberto Rosa ◽  
Levent Köroğlu ◽  
Erhan Ayas ◽  
Alpagut Kara ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Microwave Sintering ◽  
Single Mode ◽  
Nominal Composition ◽  
Indentation Fracture ◽  
Microwave Furnace ◽  
Indentation Fracture Toughness ◽  
Difference Time

α-β SiAlON/TiN composites with nominal composition of α:β = 25:75 were fabricated by microwave sintering. The effect of titanium nitride addition on the phases, microstructure, microwave absorption ability and mechanical properties (Vickers hardness and fracture toughness) of the SiAlON-based composites were studied. Finite Difference Time Domain (FDTD) software was used for the numerical simulation in order to assess the most suitable experimental setup. Sintering trials were performed in a single mode microwave furnace operating at 2.45 GHz and a power output of 660 W, for a reaction time of 30 min. SiC blocks were used as a susceptor to accelerate the microwave processing by hybrid heating, with reduced heat losses from the surface of the material of the α-β SiAlON/TiN composites. The optimum comprehensive mechanical properties, corresponding to a relative density of 96%, Vickers hardness of 12.98 ± 1.81 GPa and Vickers indentation fracture toughness of 5.52 ± 0.71 MPa.m1/2 were obtained at 850 °C when the content of TiN was 5 wt.%.

Enhanced thermoelectric and mechanical properties of p-type skutterudites with in situ formed Fe3Si nanoprecipitate

2017 ◽  
Vol 4 (10) ◽  
pp. 1697-1703 ◽  
Author(s):  
Shengyuan Peng ◽  
Jianhui Sun ◽  
Bo Cui ◽  
Xianfu Meng ◽  
Dandan Qin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Thermoelectric Properties ◽  
Indentation Fracture ◽  
Indentation Fracture Toughness ◽  
P Type

Hardness and indentation fracture toughness of La0.8Ti0.1Ga0.1Fe3CoSb12can be improved byin situformed Fe3Si, without sacrificing thermoelectric properties.

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