Study on Characteristics and Principium of Rare Earth Carbide Tools

2006 ◽  
Vol 532-533 ◽  
pp. 101-104
Author(s):  
Tie Fu ◽  
Qi Xun Yu ◽  
Si Qin Pang

Carbide tools play key roles in present machine manufacture. The mechanical property and cutting performance of carbide tools are improved obviously when adding micro rare earth (RE) elements into carbide tools. By means of some apparatus, such as materials testing machine, Scanning Electron Microscope (SEM), dynamometer, microscope and electron probe microanalyser, the traditional and RE carbide tools, P30 (YT5 and YT5R), P20 (YT14 and YT14R), M10 (YW1 and YW1R), K30 (YG8 and YG8R), are studied and compared by doing a lot of experiments. These experiments show that the bending strength, fracture toughness and anti-impact capability of RE carbide tools are improved remarkably, and their hardness increased a little. Moreover, the cutting force, tool-chip friction coefficient and wear of RE carbide tools decreased in cutting. In addition, the effect and cutting principium of RE element to carbide tools are analyzed and discussed, which is beneficial to the research and application of RE carbide tools.

2013 ◽  
Vol 423-426 ◽  
pp. 38-42
Author(s):  
Ai Min Li ◽  
Kang Ning Sun ◽  
Run Hua Fan

Carbon nanotubes/zirconia/hydroxyapatite biocomposites was prepared by hot-pressing sintering under Ar atmosphere. The influence of sintering temperature on the mechanical properties and microstructure of carbon nanotube/zirconia/hydroxyapatite biocomposites was studied. We tested the bending strength and fracture toughness by universal electronic materials testing machine. The component of the composites was tested by XRD. The fracture surface of the composites was observed by SEM. The results indicate that the bending strength and fracture toughness of the composites is lower when the sintering temperature is lower than 1200°C. The difference of bending strength and fracture toughness at 1200°C and 1300°C is little. The number of them has risen markedly than the low temperature which reached to189.2MPa and 1.8MPa·m-1/2 respectively. The composition of the composites is mainly of hydroxyapatite, zirconia, carbon nanotubes, and a small amount of calcium phosphate, which indicated that part of the hydroxyapatite has decomposed. SEM photographs show that the fracture surface of the composites sintered at 1200 °C and 1300 °C is ductile fracture status and has bigger density.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Hongming Zhou ◽  
Jian Li ◽  
Danqing Yi

-matrix composites reinforced with and SiC particles were fabricated by means of wet-mixing and heat-pressing process. Scanning electron microscope (SEM), X-ray diffractometry (XRD), polarizing microscopy, Vickers hardness tester, with a universal materials testing machine were used to investigate the morphology, grain size, hardness, fracture toughness, and bending strength of the synthesized composites. Notable effects on the bending strength and fracture toughness of caused by the addition of SiC and particles were found. The composite with 20 vol.% SiC and 20 vol.% Si3N4 particles has the highest strength and toughness, which is about 100% and 340%, respectively, higher than that of pure . The grain size of decreases gradually with the volume content of SiC and particles increasing from 0% to 40%, and -20 vol% SiC-20 vol% Si3N4 composite exhibits the minimum grain size of . The relationship between the grain size of and bending strength is not entirely fit with Hall-Petch equation. The strengthening mechanisms of the composite include fine-grain strengthening and dispersion strengthening. The toughening mechanisms of the composite include fine grain, microcracking, crack deflection, crack microbridging, and crack branching.


2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.


2012 ◽  
Vol 508 ◽  
pp. 178-182
Author(s):  
Jian Zhang ◽  
Guo Qiang Luo ◽  
Mei Juan Li ◽  
Qiang Shen ◽  
Lian Meng Zhang

Mo and Cu Were Bonded Successfully by Means of Vacuum Diffusion Bonding. The Interfacial Structure of the Joints Was Studied by Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), Energy Dispersive X-Ray Spectrometer (EDS) and X-Ray Diffraction (XRD), the Mechanical Property Is Tested by Tensile Strength Measurement. The Results Showed that the Differentatoms Diffused to each other in the Bonding Process. A Mo-Cu Solid Solution Was Formed in the Joint and with No Intermetallic Compounds. The Tensile Strength of the Joint Increased with the Increasing of Temperature, however, while the Holding Time Increased, the Strength Increased in the First Stages and then Decreases. It Were Observed that the Fracture Mode of the Joints Was a Brittle Fracture.


2014 ◽  
Vol 983 ◽  
pp. 94-98 ◽  
Author(s):  
Li Jun Wang ◽  
Jian Hui Qiu ◽  
Eiichi Sakai

The melting mixing was applied in the preparation of Multiwalled carbon nanotubes/Polycarbonate (MWCNTs/PC) nanocomposites. MWCNTs/PC nanocomposites with different MWCNTs contents were prepared under different injection conditions. The mechanical property of nanocomposites was comparatively investigated. The results demonstrated that: the tensile property of the nanocomposites was slightly improved by MWCNTs content increasing; but as the MWCNTs contents went on to increase to 10wt%, the tensile strength and bending strength were obviously decreased about 35% and 47%, respectively, but the impact strength and hardness were increased. The center hardness of MWCNTs/PC nanocomposites was greater than the surface hardness. Besides, the changes on the mechanical properties of the nanocomposites were studies by changing the injection conditions. By Scanning Electron Microscopy (SEM) observation, the microstructure and morphology of nanocomposites were analyzed, revealing that the center of the nanocomposite distributed more MWNTs, and the injection conditions would affect the MWNTs’ dispersion in the matrix and the interfacial interaction between MWCNTs and PC.


2008 ◽  
Vol 403 ◽  
pp. 111-114 ◽  
Author(s):  
Kei Asakoshi ◽  
Junichi Tatami ◽  
Katsutoshi Komeya ◽  
Takeshi Meguro ◽  
Masahiro Yokouchi

β-SiAlON powder was used as a raw powder to fabricate α/β-SiAlON composite ceramics with different rare earth elements. The phases present in the sample fabricated from -SiAlON, α-Si3N4, AlN, and rare earth oxide powders were - and -SiAlONs. The composition was dependent on the chemical composition and firing profile. The sample obtained by adding Yb2O3 had a high -SiAlON content. The /-SiAlON composite ceramics had high densit. Their microstructures depended on the used metal oxides, namely, the addition of Nd2O3 and CaCO3 resulted in the elongation of the -SiAlON grains. The bending strength, fracture toughness, and hardness were influenced by the -SiAlON content, amount of elongated grains, and density of the sample.


2014 ◽  
Vol 602-603 ◽  
pp. 407-411 ◽  
Author(s):  
Yu Hong Chen ◽  
Liang Jiang ◽  
Li Li Zhang ◽  
Zhen Kun Huang ◽  
Lan Er Wu

The densification of α-SiC occurred by liquid-phase sintering mechanism with AlN-RE2O3(RE=Nd, Gd, Y, Lu) was studied. The total additive content was fixed at 15 wt%. Cold isostatically pressed samples were sintered at 1800-1950 °C under N2atmosphere for 1 h. The linear shrinkage and weight loss of the samples were about 17-20% and 2-5%, respectively. The mechanical properties and microstructure of sintered samples were investigated. The experimental results showed that the fracture toughness of samples was 6-8 MPa·m1/2, the hardness was in the range of 18-21 GPa and the bending strength was in the range of 400-500 MPa. It was found that a decrease in the cationic radius of the rare-earth oxides was accompanied by an increase in hardness and flexural strength of the SiC ceramics, whereas the fracture toughness was improved by incorporating rare-earth oxides of larger cationic radius. The morphology (SEM) of sintered sample showed a fine grained microstructure with equiaxed grains. Fracture mode was intergranular fracture.


2007 ◽  
Vol 336-338 ◽  
pp. 1424-1425
Author(s):  
Sui Lin Shi ◽  
Ling Zhen Zhang

In this study, Al2O3-TiC composite was prepared at 1600°C for 1 h by hot-pressing using the Al2O3-TiC composite powder synthesized from self-propagating high-temperature synthesis (SHS) process. Mechanical properties of the composite were investigated, such as bulk density, Vickers hardness, fracture toughness and bending strength. The microstructure of the composite was also investigated by scanning electron microscopy (SEM).


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