scholarly journals Sintering Mechanism, Microstructure Evolution, and Mechanical Properties of Ti-Added Mo2FeB2-Based Cermets

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1889
Author(s):  
Yupeng Shen ◽  
Zhifu Huang ◽  
Lei Zhang ◽  
Kemin Li ◽  
Zhen Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Liquid Phase ◽  
Rupture Strength ◽  
Liquid Phase Sintering ◽  
Maximum Hardness ◽  
Liquid Phases ◽  
Ti Content ◽  
Ti Addition

Four series of Mo2FeB2-based cermets with Ti contents between 0 wt.% and 1.5 wt.% in 0.5 wt.% increments were prepared by in situ reaction and liquid phase sintering technology. Influences of Ti on microstructure and mechanical properties of cermets were studied. It was found that Ti addition increases formation temperatures of liquid phases in liquid-phase stage. Ti atoms replace a fraction of Mo atoms in Mo2FeB2 and the solution of Ti atoms causes the Mo2FeB2 crystal to be equiaxed. In addition, the cermets with 1.0 wt.% Ti content exhibit the smallest particle size. The solution of Ti atoms in Mo2FeB2 promotes the transformation of Mo2FeB2 particles from elongated shape to equiaxed shape. With Ti content increasing from 0 wt.% to 1.5 wt.%, the hardness and transverse rupture strength (TRS) first increase and then decrease. The maximum hardness and TRS occur with 1.0 wt.% Ti content. However, the fracture toughness decreases as Ti content increases. The cermets with 1.0 wt.% Ti content show excellent comprehensive mechanical properties, and the hardness, fracture toughness, and TRS are HRA 89.5, 12.9 MPa∙m1/2, and 1612.6 MPa, respectively.

Microstructure and Mechanical Properties of Mo2FeB2 Based Cermets Containing SiC Whisker

2012 ◽  
Vol 625 ◽  
pp. 304-307 ◽  
Author(s):  
Hai Zhou Yu ◽  
Wen Jun Liu ◽  
Lian Ying ◽  
Min You
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Boundary ◽  
Grain Growth ◽  
Rupture Strength ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Hard Phase ◽  
Maximum Hardness ◽  
Vacuum Sintering

Four series of cermets with the SiC whisker content between 0 and 1.0 wt.% were prepared by vacuum sintering. The transverse rupture strength (TRS), hardness (HRA) and fracture toughness (KIC) were also measured. The SiC whiskeraddition was located at the grain boundaries, which prevented grain boundary migration and restrained the grain growth. However, an increasing SiC whisker content decreased the wettability of the binder on the Mo2FeB2 hard phase. The highest TRS and fracture toughness was found for the cermets with 0.5 wt.% SiC whisker addition, whereas the cermets without SiC whisker addition exhibited the maximum hardness.

The Influence of Processing Parameters on Mechanical Properties of Spark Plasma Sintered Chromium Carbide Based Cermets

2017 ◽  
Vol 267 ◽  
pp. 162-166
Author(s):  
Kristjan Juhani ◽  
Jüri Pirso ◽  
Marek Tarraste ◽  
Mart Viljus ◽  
Sergei Letunovitš
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Liquid Phase ◽  
Chromium Carbide ◽  
Processing Parameters ◽  
Liquid Phase Sintering ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintered Chromium

Present paper discusses the influence of spark plasma sintering (SPS) on the microstructure and perfomances of chromium carbide based cermets. The effect of SPS parameters (temperature, pressure) is discussed. It is shown that SPS enables to produce more fine grained chromium carbide based cermets compared to conventional liquid phase sintering. Hardness and fracture toughness are exhibited.

Development of High Strength Mo2NiB2 Ternary Boride Base Cermets Produced by Reaction Boronizing Sintering

2007 ◽  
Vol 539-543 ◽  
pp. 803-808 ◽  
Author(s):  
Kenichi Takagi ◽  
Yuji Yamasaki ◽  
Koro Hirata
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Rupture Strength ◽  
High Strength ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Mass Model ◽  
Transverse Rupture Strength ◽  
Ternary Boride

The effects of V substitution for Cr to the sintering behavior of Cr containing Mo2NiB2 ternary boride base cermets and Mn addition to the mechanical properties and microstructure of the Cr and V containing cermets were investigated by using Ni-5.0B-51.0Mo-(17.5-x)Cr-xV (mass%) and Ni-5.0B-51.0Mo-12.5Cr-5.0V-(0-1.5)Mn (mass%) model cermets. 10mass%V substitution for Cr in the Cr containing cermets markedly improved transverse rupture strength and hardness from 2.27 to 2.94GPa and from 85.3 to 87.2RA respectively and refined the microstructure by retarding the progress of sintering especially at liquid phase sintering stage. Small amount of Mn addition to the Cr and V containing Mo2NiB2 base cermets significantly improved the sinterability and increased the mechanical properties of the cermets.

Preparation and Mechanical Properties of Nanocobalt Coated Al2O3-TiC Composites

2007 ◽  
Vol 334-335 ◽  
pp. 913-916 ◽  
Author(s):  
Yan Sheng Yin ◽  
Shou Gang Chen ◽  
Xue Ting Chang ◽  
Alan Kin Tak Lau
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Liquid Phase ◽  
Fracture Surface ◽  
Bending Strength ◽  
Liquid Phase Sintering ◽  
Sem Images ◽  
Coating Layers ◽  
Cobalt Coating ◽  
Refinement Effect

Al2O3-TiC composites were fabricated by hot-pressing Cobalt coated powders at low temperature through liquid phase sintering. Cobalt coating layers effectively hinder the growth of grain and harmful reaction between Al2O3 and TiC particles, which would improve the mechanical properties of Al2O3-TiC composites. The hardness decreases with the increase of Co content and the bending strength was enhanced to 782MPa owing to the grain refinement effect of Co phase. The fracture toughness, about 9.23 MPa.m1/2, was measured for the composites containing 3wt% Co sintered at 1550°C. SEM images of fracture surface show that the toughening effect should be attributed to the conversion of fracture mode caused by the Co phase.

Effect of Glassy Phase Additions to Zirconia on its Mechanical Properties

2012 ◽  
Vol 727-728 ◽  
pp. 940-944
Author(s):  
Vera Lúcia Praxedes de Oliveira ◽  
Marcelo Henrique Prado da Silva ◽  
Eduardo de Sousa Lima ◽  
Claudinei dos Santos ◽  
Luis Henrique Leme Louro
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Liquid Phase ◽  
Mechanical Strength ◽  
Glassy Phase ◽  
Vickers Microhardness ◽  
Liquid Phase Sintering ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Four Point Bending

Glasses with two different compositions were added to yttria-stabilized zirconia TZP powder: a CAS glass and a bioactive glass. These additions allowed liquid phase sintering to occur at temperature as low as 1300 °C. The concentrations of each glass additions were of 1, 3, and 5 wt%. The prepared compositions were uniaxially pressed at 50 MPa and sintered at 1300oC for 2 hours. The sintered samples were characterized for their mechanical properties, by measuring four-point bending mechanical strength, Vickers microhardnesses, and fracture toughness ( KIc ). Vickers microhardness measured values ranged from 10 to 12 GPa, while fracture toughness, from 3.8 to 4.4 MPa.m1/2. The flexural mechanical strength was situated between 302 and 408 MPa. The achieved mechanical properties, from sintered samples were possible due to glassy phase additions. These properties, associated to biocompatibility, enable such materials to be used in different applications, including bioceramics.

Effect of Ti(C0.7N0.3) Content on the Microstructure and Mechanical Properties of Ni Bonded NbC-Ti(C0.7N0.3) Based Cermets

2018 ◽  
Vol 274 ◽  
pp. 43-52
Author(s):  
S.G. Huang ◽  
J. Vleugels ◽  
H. Mohrbacher ◽  
M. Woydt
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Grain Size ◽  
Liquid Phase ◽  
Grain Growth ◽  
Xrd Analysis ◽  
Liquid Phase Sintering ◽  
Partial Replacement ◽  
Microstructural Investigation

NbC-xTi (C0.7N0.3)-10Ni-7.5VC (vol%) based cermets with 0, 5, 10, 15 or 25 vol% Ti (C0.7N0.3) were prepared by conventional pressureles liquid phase sintering at 1420°C in vacuum. Detailed microstructural investigation was performed by SEM, EPMA and XRD analysis. Sintering results indicated that the partial replacement of NbC by Ti (C0.7N0.3) had a significant effect on the carbide grain growth, microstructure, hardness as well as fracture toughness of the fully densified NbC-based cermets. The Ti (C0.7N0.3)-free NbC cermet was composed of homogeneous cubic (Nb,V)C solid solution grains, whereas core-rim structured NbC grains were observed in cermets with Ti (C0.7N0.3) addition. All sintered cermets with  15 vol% Ti (C0.7N0.3) were composed of a fcc solid solution Ni binder and a cubic core-rim solid solution (Nb,V,Ti)C phase with a Nb-rich core and a Ti-rich rim. 3.8 vol% of residual pristine Ti (C0.7N0.3) was present in the cermets with 25 vol% Ti (C0.7N0.3) addition. The 15 vol% Ti (C0.7N0.3) starting powder based cermet exhibited the finest average NbC grain size of 1.48 μm, with a core-rim structure and an interesting combination of hardness (1486 kg/mm2) and fracture toughness (8.7 MPa.m1/2).

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