The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Ji Xiong - One of the best experts on this subject based on the ideXlab platform.
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structure and properties of pvd tialn and tialn craln coated ti c n based Cermets
Ceramics International, 2017Co-Authors: Wei Yang, Ji Xiong, Hao Du, Tianen Yang, Jun TangAbstract:Abstract Ti(C, N)-based Cermets were coated with TiAlN and TiAlN/CrAlN films by physical vapor deposition. The cross-sectional morphology was characterized by scanning electron microscopy (SEM), and the adhesive strength was evaluated by the scratch test. Cutting tests on the coated Cermets were conducted on the different cutting conditions. The cutting performance and wear mechanism were analyzed with SEM and EDS. It is found that TiAlN coating has a better adhesion to the Cermet substrate. The coated Cermet inserts show better wear resistance than the uncoated ones. By contrast, the TiAlN coating suffers a slight abrasive flank wear. However, the TiAlN/CrAlN coating show more severe adhesive flank wear because of the Cr interdiffusion between the inserts and the workpiece. In addition, TiAlN coating is weak in resisting against oxidation wear, while the TiAlN/CrAlN coating has an excellent resistance to oxidation.
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fracture origin and intrinsic strength of ultra fine tic0 7n0 3 based Cermet
International Journal of Refractory Metals & Hard Materials, 2007Co-Authors: Ji Xiong, Baoluo ShenAbstract:Abstract Transverse rupture strength of Ti(C,N)-based Cermets is largely affected by the fracture origins. In this paper, ultra-fine Cermet of low binder content is prepared with 0.13 μm TiC 0.7 N 0.3 powder, and the fracture origin of the Cermet is studied. The results show that the oxygen content of the ultra-fine TiC 0.7 N 0.3 powder can be decreased by heating it in vacuum sintering furnace; 90% of the fracture origins are pores, and there are also a few Ni pools and carbide aggregations. The intrinsic strength of the prepared ultra-fine TiC 0.7 N 0.3 -based Cermet is calculated to be 5000 MPa, much larger than the measured transverse rupture strength; HIP process can decrease the size of pores, and improve the transverse rupture strength of ultra-fine TiC 0.7 N 0.3 -based Cermet.
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the effect of wc mo2c tac content on the microstructure and properties of ultra fine tic0 7n0 3 Cermet
Materials & Design, 2007Co-Authors: Ji Xiong, Baoluo Shen, Zhixing Guo, Ding CaoAbstract:Abstract The effect of Mo2C, WC and TaC on the microstructure and properties of ultra-fine TiC0.7N0.3 Cermet is studied. A series of Cermets of varying nominal composition are prepared with ultra-fine powders, following normal powder metallurgical procedures. The results show that the addition of Mo2C leads to the appearance of black cores in the ultra-fine Cermet, which cannot be seen in medium particle Cermet. However, excessive addition will result in the thickening of the rim, and the property goes down; the addition of WC makes the microstructure of TiC0.7N0.3–10 wt%Mo2C–14.5%NiCo Cermet more complex, and many white cores appear in it; excessive addition will be detrimental for the hardness and strength of the Cermet, and in ultra-fine TiC0.7N0.3–14.5%NiCo Cermet, the optimum addition level of Mo2C, WC and TaC is 10, 15 and 7 wt%, respectively.
Shinhoo Kang - One of the best experts on this subject based on the ideXlab platform.
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effect of nitrogen and secondary carbide on the microstructure and properties of ti0 93w0 07 c ni Cermets
International Journal of Refractory Metals & Hard Materials, 2014Co-Authors: Seyed Mahdi Rafiaei, Shinhoo KangAbstract:Abstract Solid-solution powders of (Ti 0.93 W 0.07 )C and (Ti 0.93 W 0.07 )(C 0.7 N 0.3 ) were synthesized via high-energy ball milling and carbothermal reduction processes. After blending powders with Ni and other carbides, Cermets were prepared by a blending and sintering process at 1510 °C for 1 h. We observed a typical core/rim structure consisting of solid solution phases. We also found that secondary carbide and nitrogen have a remarkable influence on the Cermet microstructures. Further, with an increase in the Mo 2 C content, the mechanical properties of these Cermets were enhanced significantly; the hardness of carbide and carbonitride Cermets increased from 9.3 and 12.7 to 12.9 and 13.9 GPa, respectively. All results are discussed in terms of the thermodynamic stability and dissolution behavior of the constituent carbides and carbonitride.
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1.05 – Cermets
Comprehensive Hard Materials, 2014Co-Authors: Shinhoo KangAbstract:Ti(CN)-based Cermets have been introduced into the field of cutting tools because of their high hardness, strength, wear resistance and phase stability that is necessary for high-temperature processing. Due to their improved mechanical properties and low price compared to WC-Co, Cermet tools are currently replacing some of the cutting tools, where cemented carbide tools have previously been dominant. Ti(CN)-based Cermets are modified with coating layers such as chemical vapor deposition coatings or functionally graded material to improve toughness. In this chapter, we have reviewed some recent developments in the Cermet field. In order to provide better understanding in the microstructure and performance of various Cermets, we paid attention to the basics and fundamentals of carbides and Cermets. First of all, thermodynamic issues related to the characteristics of Ti(CN), its stability domain, the formation of solid-solution carbonitrides, and carbothermal reduction were discussed in detail since the phase reaction dominates based on the energy involved in determining final microstructure. Second, other factors influencing the microstructure, such as instability of carbides, dissolution/precipitation, strain effect, particle size, solid-solution carbides of high stability, and binder phase, were briefly explained. Finally, we added short experimental results in relation with surface microstructure.
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Tool Performance of New Wear-resistant Cermets
International Journal of Precision Engineering and Manufacturing, 2012Co-Authors: Won Tae Kwon, Shinhoo KangAbstract:Ti(C,N)-based Cermets were recently designed for tool applications as they offer enhanced interfacial strength. Such a Cermet exhibits a typical core/rim microstructure as found in conventional Cermets. To determine the possibility of using new Cermet as a cutting tool, Ti(C,N) along with various carbides, nitrides, solid-solution carbonitride such as (Ti,W)(C,N), and Ni were milled together, sintered into the size of SNGN120408 and used in turning the SM45C (AISI45). Commercial WC and Cermet insert of an identical size were selected to compare its cutting capability with that of the home-made Cermet tool. To ensure a fair comparison of the cutting performance, the optimal machining conditions for commercial WC, Cermet and home-made Cermet tools were obtained using the Taguchi method. Experiments under both optimal conditions showed the excellent cutting performance of the new home-made Cermet tool. It is believed that the interface between core Ti(C,N) and rim phases has been improved significantly in the new Cermets.
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electro discharge machining performance of ticn based Cermets
International Journal of Refractory Metals & Hard Materials, 2007Co-Authors: B Manoj V Kumar, Janakarajan Ramkumar, Bikramjit Basu, Shinhoo KangAbstract:Abstract The present investigation aims at evaluating the die sinking electro-discharge machining (EDM) performance of TiCN–20 wt.% Ni Cermets containing 10 wt.% of different secondary carbides: WC, NbC and TaC. Such performance is assessed in terms of making cavity of 1 mm depth on a commercial high speed tool steel (HSS). The material removal rate (MRR) is found to be higher for TiCN–20 wt.% Ni Cermet; however tool wear ratio (TWR) is lower for TiCN–20Ni–10TaC Cermet. The quality of Cermet tool surface has been quantitatively assessed using surface roughness tester and it was observed that the roughness (Ra or Rz) of TiCN–20Ni–10TaC Cermet tool surface is lower, when compared with that of other investigated Cermets. SEM–EDAX analysis of EDM surfaces reveal melting and evaporation of the binder as well as pull-out and spalling of brittle carbonitride/carbide grains as the dominant wear mechanisms. The layer formation due to solidification of molten layer and/or transfer of material from workpiece is commonly observed for all the Cermet tool surfaces.
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microstructure and tribo mechanical properties of ultrafine ti cn Cermets
International Journal of Refractory Metals & Hard Materials, 2002Co-Authors: E T Jeon, J Joardar, Shinhoo KangAbstract:Abstract Role of Ti(CN) particle size on the microstructure of the Ti(CN)–WC–Ni Cermets has been evaluated. The systems containing ultrafine grade Ti(CN) shows better structural homogeneity and a large volume fraction of rim phase in the core-rim structure when compared to the coarse Ti(CN) Cermets. Measurable shift in the lattice parameter of the Ti(CN) core occurs in the ultrafine grade Cermet possibly due to the diffusion of W and/or Ni. The improved structural features in the ultrafine grade led to considerably enhanced tribo-mechanical properties of the Cermets.
Baoluo Shen - One of the best experts on this subject based on the ideXlab platform.
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fracture origin and intrinsic strength of ultra fine tic0 7n0 3 based Cermet
International Journal of Refractory Metals & Hard Materials, 2007Co-Authors: Ji Xiong, Baoluo ShenAbstract:Abstract Transverse rupture strength of Ti(C,N)-based Cermets is largely affected by the fracture origins. In this paper, ultra-fine Cermet of low binder content is prepared with 0.13 μm TiC 0.7 N 0.3 powder, and the fracture origin of the Cermet is studied. The results show that the oxygen content of the ultra-fine TiC 0.7 N 0.3 powder can be decreased by heating it in vacuum sintering furnace; 90% of the fracture origins are pores, and there are also a few Ni pools and carbide aggregations. The intrinsic strength of the prepared ultra-fine TiC 0.7 N 0.3 -based Cermet is calculated to be 5000 MPa, much larger than the measured transverse rupture strength; HIP process can decrease the size of pores, and improve the transverse rupture strength of ultra-fine TiC 0.7 N 0.3 -based Cermet.
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the effect of wc mo2c tac content on the microstructure and properties of ultra fine tic0 7n0 3 Cermet
Materials & Design, 2007Co-Authors: Ji Xiong, Baoluo Shen, Zhixing Guo, Ding CaoAbstract:Abstract The effect of Mo2C, WC and TaC on the microstructure and properties of ultra-fine TiC0.7N0.3 Cermet is studied. A series of Cermets of varying nominal composition are prepared with ultra-fine powders, following normal powder metallurgical procedures. The results show that the addition of Mo2C leads to the appearance of black cores in the ultra-fine Cermet, which cannot be seen in medium particle Cermet. However, excessive addition will result in the thickening of the rim, and the property goes down; the addition of WC makes the microstructure of TiC0.7N0.3–10 wt%Mo2C–14.5%NiCo Cermet more complex, and many white cores appear in it; excessive addition will be detrimental for the hardness and strength of the Cermet, and in ultra-fine TiC0.7N0.3–14.5%NiCo Cermet, the optimum addition level of Mo2C, WC and TaC is 10, 15 and 7 wt%, respectively.
Ding Cao - One of the best experts on this subject based on the ideXlab platform.
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the effect of wc mo2c tac content on the microstructure and properties of ultra fine tic0 7n0 3 Cermet
Materials & Design, 2007Co-Authors: Ji Xiong, Baoluo Shen, Zhixing Guo, Ding CaoAbstract:Abstract The effect of Mo2C, WC and TaC on the microstructure and properties of ultra-fine TiC0.7N0.3 Cermet is studied. A series of Cermets of varying nominal composition are prepared with ultra-fine powders, following normal powder metallurgical procedures. The results show that the addition of Mo2C leads to the appearance of black cores in the ultra-fine Cermet, which cannot be seen in medium particle Cermet. However, excessive addition will result in the thickening of the rim, and the property goes down; the addition of WC makes the microstructure of TiC0.7N0.3–10 wt%Mo2C–14.5%NiCo Cermet more complex, and many white cores appear in it; excessive addition will be detrimental for the hardness and strength of the Cermet, and in ultra-fine TiC0.7N0.3–14.5%NiCo Cermet, the optimum addition level of Mo2C, WC and TaC is 10, 15 and 7 wt%, respectively.
Bikramjit Basu - One of the best experts on this subject based on the ideXlab platform.
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Fretting Wear Properties of TiCN-Ni Cermets: Influence of Load and Secondary Carbide Addition
Metallurgical and Materials Transactions A, 2008Co-Authors: B.v. Manoj Kumar, Bikramjit BasuAbstract:The increasing demand for TiCN-based Cermets in tribological applications necessitates a thorough understanding of the influence of experimental as well as material parameters on the friction and wear properties. In optimizing microstructure and properties, secondary carbides are added to baseline TiCN-Ni Cermet. The present work aims at evaluating the fretting wear behavior of Ti(CN)-Ni Cermets containing various secondary carbides, such as WC, NbC, TaC, and HfC, against steel at different loading (2, 6, and 10 N) conditions. The evolution of tangential frictional force for the investigated Cermets was analyzed in terms of fretting logs and fretting loops. The topographical characterization of worn surfaces was performed, using laser surface profilometry and a scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS) capability. The steady-state coefficient of friction (COF) was minimum (0.33) for a TiCN-20Ni Cermet/steel tribocouple, while a maximum COF (0.47) was recorded for TiCN-20Ni-10HfC Cermet/steel at a 2-N load. The wear rate of the Cermets varied in the range of 1.7 × 10^−6 to 3.5 × 10^−6 mm^3/Nm. The TiCN-20Ni-10HfC Cermet exhibited poor wear resistance among investigated Cermets. The dominant wear mechanisms were found as abrasion and tribolayer formation. The dominance of abrasion is explained in terms of cumulative energy dissipation.
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crater wear mechanisms of ticn ni wc Cermets during dry machining
International Journal of Refractory Metals & Hard Materials, 2007Co-Authors: B Manoj V Kumar, Ram J Kumar, Bikramjit BasuAbstract:Abstract TiCN–Ni-based Cermets are attractive cutting tools because of the combination of high hardness and wear resistance with improved toughness and thermal shock resistance. The present work reports the effect of WC addition (0–15 wt.%) on the machining performance of TiCN–20 wt.% Ni Cermets against boiler steel. The cutting force was measured on-line using dynamometer, with respect to varying cutting speed and feed rate, in dry and orthogonal cutting conditions. The principal aim of the present investigation is to evaluate the dominant mechanisms, responsible for material removal on the rake face of Cermets, using SEM–EDS. The cutting performance of TiCN–Ni Cermet is observed to improve with the addition of WC content upto 10 wt.%. While, the adhesion of tribochemical layer is dominant with limited WC content, the presence of abrasive grooves and pull-outs are observed for TiCN–20Ni Cermets containing higher amount of WC (>10 wt.%).
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electro discharge machining performance of ticn based Cermets
International Journal of Refractory Metals & Hard Materials, 2007Co-Authors: B Manoj V Kumar, Janakarajan Ramkumar, Bikramjit Basu, Shinhoo KangAbstract:Abstract The present investigation aims at evaluating the die sinking electro-discharge machining (EDM) performance of TiCN–20 wt.% Ni Cermets containing 10 wt.% of different secondary carbides: WC, NbC and TaC. Such performance is assessed in terms of making cavity of 1 mm depth on a commercial high speed tool steel (HSS). The material removal rate (MRR) is found to be higher for TiCN–20 wt.% Ni Cermet; however tool wear ratio (TWR) is lower for TiCN–20Ni–10TaC Cermet. The quality of Cermet tool surface has been quantitatively assessed using surface roughness tester and it was observed that the roughness (Ra or Rz) of TiCN–20Ni–10TaC Cermet tool surface is lower, when compared with that of other investigated Cermets. SEM–EDAX analysis of EDM surfaces reveal melting and evaporation of the binder as well as pull-out and spalling of brittle carbonitride/carbide grains as the dominant wear mechanisms. The layer formation due to solidification of molten layer and/or transfer of material from workpiece is commonly observed for all the Cermet tool surfaces.
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Electrochemical Behavior of TiCN–Ni‐Based Cermets
Journal of the American Ceramic Society, 2006Co-Authors: B.v. Manoj Kumar, R. Balasubramaniam, Bikramjit BasuAbstract:The electrochemical behavior of TiCN-20 wt% Ni Cermets containing different secondary carbides (10 wt% WC, NbC, TaC, and HfC) was investigated in freely aerated 0.2 mol/L sulfuric acid. A comparison has also been made with polarization behavior of pure Ni. All the materials (except HfC-containing Cermet) exhibited active-passive polarization behavior, characterized by two passive regions. The first passive region, obtained on polarizing past the zero current potential, was attributed to passive film formation due to TiCN, while the second passive film is presumably due to the presence of a Ni binder phase. The passivation behavior in the case of Cermets containing various secondary carbides (WC, TaC, and NbC) was similar to baseline TiCN-20Ni Cermets, while poor passivation behavior was observed in the case of TiCN-20Ni-10HfC. Efforts have been made to correlate the passivation behavior with the microstructural characteristics of sintered Cermets.