Microstructure, Mechanical Properties, Sintering and Fracture Behavior of Ti(C, N) Based Cermets Granules/Ti(C, N) Based Cermets Composite

2020 ◽  
Vol 837 ◽  
pp. 139-145
Author(s):  
Ai Jun Liu ◽  
Gang Li ◽  
Ning Liu ◽  
Ke Bei Chen ◽  
Hai Dong Yang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Fracture Behavior ◽  
Rupture Strength ◽  
Binder Phase ◽  
Hard Phase ◽  
Opposite Trend ◽  
The Matrix ◽  
Sintering Properties

Effect of Ti (C,N) based cermets granule on the microstructure, mechanical properties, sintering and fracture behavior of Ti (C,N) based cermets was investigated. Results show that the Ti (C,N) based cermets granules distribute in the matrix homogeneously. A nanoindentation study was performed on hard phase and binder phase in the matrix and granule. With the increase of granules content, sintering properties is worse. With the increase of granules content, transverse rupture strength (TRS) and relative density decrease gradually, while the hardness has an opposite trend. The fracture toughness increases firstly with increasing granule, and then decreases with the further increase of granules. Higher fracture toughness of the cermets is mainly owing to the crack branch and higher fracture energy of coarse granule.

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.

Effect of Ball-Milling Time on the Microstructure and Mechanical Properties of Submicron Ti(C,N)-Based Cermets

2013 ◽  
Vol 589-590 ◽  
pp. 584-589
Author(s):  
Hui Jun Zhou ◽  
Chuan Zhen Huang ◽  
Bin Zou ◽  
Han Lian Liu ◽  
Hong Tao Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Ball Milling ◽  
Milling Time ◽  
Rupture Strength ◽  
Submicron Particles ◽  
Titanium Carbonitride ◽  
Hard Phase ◽  
Ball Milling Time ◽  
Scanning Electron

In this study, titanium carbonitride (Ti(C,N)) based cermets were prepared by submicron particles, sintered in a vacuum and hot-pressing furnace. And the effect of different ball-milling time (36 h, 48 h, 60 h and 72 h, respectively, mostly aimed for mixing) on the mechanical properties of Ti(C,N)-based cermets, including transverse rupture strength (TRS), Vickers hardness (HV20), fracture toughness (KIC) and microstructure were investigated. The results showed that the TRS, hardness and fracture toughness were all improved with an increase in ball-milling time (not more than 60 h). Scanning electron microscopy (SEM) investigations on the microstructure of cermets with different ball-milling time revealed that the compound powders were not very well-distributed as a whole and there were coarse hard phase grains, but the microstructure was very homogeneous in parts, and the microstructure of cermets with a ball-milling time of 60 h is relatively more homogeneous. So a refinement to Ti(C,N) raw particles is needed in later studies.

Effects of Carbon Nanotubes Incorporation on the Grain Growth and Properties of WC/Co Nanocomposites

2005 ◽  
Vol 475-479 ◽  
pp. 989-992 ◽  
Author(s):  
Fa Ming Zhang ◽  
Jian Fei Sun ◽  
Jun Shen
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Grain Growth ◽  
Binder Phase ◽  
Tubular Structures ◽  
Plasma Sintering ◽  
Mechanical And Physical Properties ◽  
The Matrix ◽  
Spark Plasma

Carbon nanotubes (CNTs) combining unique mechanical and physical properties could offer a kind of nanosized reinforcements for composite materials. Incorporating of CNTs to develop advance engineering composites has become an interesting concept, but the cermets based CNTs composites have been less focused. WC-Co-CNTs nanocomposites were consolidated by spark plasma sintering (SPS) to investigate the effects of CNTs incorporation on the grain growth and mechanical properties of WC-Co nanocomposites. Experimental results show that CNTs could preserve their tubular structures in high temperature SPS process, some CNTs are surviving in the WC-Co fracture surfaces featured bridging and pulling out manner. The interaction between the CNTs and the matrix has a retardation effect of grain growth of WC, but CNTs additions could be resulted in an increase of carbon content in the binder phase that causes enhanced tendency of grain growth, either of which plays the dominated role depending on the CNTs content. The WC-10Co-0.5wt%CNTs nanocomposites possess superior hardness to toughness combinations, which hardness is about 15% and fracture toughness is about 40% higher than that of the pure nano-WC-10Co cermets consolidated under the same process.

Research on Effect of Cr3C2 Addition on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermets

2014 ◽  
Vol 697 ◽  
pp. 46-50
Author(s):  
Hai Long Wei ◽  
Hai Yan Lei ◽  
Guo Xiong Zhong ◽  
Hai Zhou Yu ◽  
Ping Feng
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Volume Fraction ◽  
Rupture Strength ◽  
Binder Phase ◽  
Mass Ratio ◽  
Black Core ◽  
Core Volume ◽  
Scanning Electron

Four Ti (C,N)-based cermets with Cr3C2 content of 0.3%, 0.6%, 0.9% and 1.2 % in mass ratio were sintered in vacuum at 1430oC, 1450oC, 1465oC and 1480oC. The mechanical properties of the specimens were determinted and microstructures were observed using the scanning electron microscope (SEM) to study the effect of Cr3C2 content on mechanical properties and microstructure. The results show that the four Ti (C,N)-based cermets sintered at 1465oC have the best overall mechanical properties; and among them, the cermet with 0.6% Cr3C2 has the best overall mechanical properties, i.e. transverse rupture strength (TRS) 1967MPa, hardness 1556HV and fracture toughness (KIC) 9.5MPa.m1/2. With the increase of Cr3C2 content, the black core volume fraction firstly increases and then decreases, the white core decreases in a progressive and continuous manner, the rim phase firstly increases and then decreases, the binder phase firstly decreases and then increases.

Effects of the Content of ZrO2 Nanoparticles on the Microstructure and Properties of Al2O3-TiC-ZrO2 Micro-Nano-Composites

2013 ◽  
Vol 652-654 ◽  
pp. 304-307
Author(s):  
Wei Min Liu ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Microstructural Characterization ◽  
Zro2 Nanoparticles ◽  
Nano Composites ◽  
Sintering Aids ◽  
Agglomeration Effect ◽  
The Matrix

Al2O3-TiC-ZrO2 micro-nano-composites with addition of ZrO2 nanoparticles were fabricated by vaccum hot pressing with Mo and Ni powders as sintering aids. Results showed that the mechanical properties and relative density of the micro-nano-composites increased firstly and then decreased with the increase in the content of ZrO2 nanoparticles. Al2O3-TiC-ZrO2 micro-nano-composites containing about 4vol% ZrO2 nanoparticles have the highest synthetical properties, its flexural strength, Vicker's hardness, Fracture Toughness and relative density are 920MPa, 20.4GPa, 6.3MPa•m1/2 and 98.9%, respectively. The microstructural characterization revealed that adding proper ZrO2 nanoparticles to the matrix can greatly strengthen the grain boundaries, causing more transgranular fractures and consuming more fracture energy. The excessive amount of ZrO2 nanoparticles may bring about agglomeration effect, leading to the decrease of properties of the micro-nano-composites.

scholarly journals Influence of Cr3C2 and VC Content on WC Grain Size, WC Shape and Mechanical Properties of WC–6.0 wt. % Co Cemented Carbides

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1551
Author(s):  
Chao Yin ◽  
Yingbiao Peng ◽  
Jianming Ruan ◽  
Lin Zhao ◽  
Ren Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Rupture Strength ◽  
Theoretical Calculations ◽  
Cemented Carbides ◽  
Triangular Prism ◽  
Binder Phase ◽  
Doping Amount ◽  
Strong Response

In this paper, the influences of Cr3C2/VC content on WC grain size, WC grain shape and mechanical properties of WC–6 wt. % Co cemented carbides were investigated. The results showed that the grain size first rapidly decreased and then slightly decreased with the increasing Cr3C2/VC content, and VC led to finer grain size and narrower size distribution. HRTEM/EDS analysis of the WC/Co interface indicates that the segregation concentration of V is much larger than that of Cr, which may be a strong response to the higher inhibition efficiency of VC. The addition of Cr3C2 induced triangular prism shape WC grains while VC generated stepped triangular prism grains. Despite the grain growth inhibitor (GGI) mechanisms of Cr3C2/VC have been extensively studied in the literature, the doping amount, especially the doping limit, has not been systematically investigated. In this work, the saturated solubilities of Cr and V in cobalt binder phase along with carbon content hare been predicted based on thermodynamic calculations. Based on the theoretical calculations, the doping amount of Cr3C2/VC is designed to be gradually increasing until more or less over their maximum solubilities in the binder phase, thereby investigating the subsequent microstructure and mechanical properties. When the doping of Cr3C2/VC exceeds the maximum solubility in Co phase, Co-rich Cr-carbides and Co-deficient V-carbides would form respectively, which were detrimental to the transverse rupture strength (TRS) and impact toughness. The hardness increased with the increasing Cr3C2/VC content, while the fracture toughness decreased with the increasing Cr3C2/VC content. The TRS initially enhanced and then declined, but the stepped triangular prism shape grains and low fraction of WC/Co interface in WC–6Co–VC cemented carbide led to a more pronounced decline in the TRS. The sample with 0.6 wt. % Cr3C2 addition had good comprehensive mechanical properties, its hardness, fracture toughness and TRS were 1880 kg/mm2, 9.32 MPa·m1/2 and 3450 MPa, respectively.

scholarly journals Efficient Improvement in Fracture Toughness of Laminated Composite by Interleaving Functionalized Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2509
Author(s):  
Seyed Mohammad Javad Razavi ◽  
Rasoul Esmaeely Neisiany ◽  
Moe Razavi ◽  
Afsaneh Fakhar ◽  
Vigneshwaran Shanmugam ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Behavior ◽  
Laminated Composite ◽  
Carbon Phase ◽  
Reinforced Composite ◽  
Reinforcing Agent ◽  
The Matrix ◽  
As Stress ◽  
Double Cantilever Beam Test ◽  
Pan Nanofiber

Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites’ fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

Effects of Sintering Additives on the Microstructure and Mechanical Properties of Silicon Nitride Ceramics by GPS

2010 ◽  
Vol 105-106 ◽  
pp. 27-30 ◽  
Author(s):  
Wei Ru Zhang ◽  
Feng Sun ◽  
Ting Yan Tian ◽  
Xiang Hong Teng ◽  
Min Chao Ru ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Transformation ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Additives ◽  
Microstructure And Mechanical Properties ◽  
Nitride Ceramics

Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3. Effect of sintering additives on the phase-transformation, microstructure and mechanical properties of porous silicon nitride ceramics was investigated. The results show that the reaction of sintering additives each other and with SiO2 had key effects on the phase-transformation, grain growing and grain boundaries. With 9MPa N2 atmosphere pressure, holding 1h at 1850°C, adding 10wt% one of the La2O3, Sm2O3, Al2O3, porous silicon nitride was prepared and the relative density was 78%, 72%, 85% respectively. The flexural strength was less than 500MPa, and the fracture toughness was less than 4.8MPam1/2. Dropping compounds sintering additives, such as La2O3+Al2O3, Sm2O3+Al2O3 effectively improves the sintering and mechanical properties. The relative density was 99.2% and 98.7% with 10wt% compounds sintering additives. The grain ratio of length to diameter was up to 1:8. The flexural strength was more than 900MPa, and the fracture toughness was more than 8.9MPam1/2.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

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