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Shinhoo Kang - One of the best experts on this subject based on the ideXlab platform.

  • 1.05 – Cermets
    Comprehensive Hard Materials, 2020
    Co-Authors: Shinhoo Kang
    Abstract:

    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.

  • carbide binder interfaces in ti cn ti w c ti w cn based Cermets
    Journal of Alloys and Compounds, 2016
    Co-Authors: Choongkwon Park, Shinhoo Kang
    Abstract:

    Abstract Partially solutionized carbide Cermets (PSCs) were prepared for cutting tool applications by replacing a portion of Ti(CN) with (Ti 0.88 W 0.12 )C or (Ti 0.88 W 0.12 )(C 0.7 N 0.3 ) in a conventional Ti(CN)-based cermet. The PSC containing (Ti 0.88 W 0.12 )C exhibited high fracture toughness with no loss of hardness. The elimination of Ti(C 0.7 N 0.3 ) cores in the microstructure reduced the strain at the core/rim interfaces, leading to the increase in fracture toughness. The PSC containing (Ti 0.88 W 0.12 )C showed coherent relationships at the core/rim and rim/binder interfaces, contributing to the improved mechanical properties. In contrast, nitrogen in (Ti 0.88 W 0.12 )(C 0.7 N 0.3 ) resulted in a different microstructure and properties. The major factors determining the mechanical properties of the Cermets are discussed in terms of the carbide/binder interfaces and the thermal stability of the added carbides.

  • Sliding Wear Behavior of TaC-Containing Ti(CN)-WC-Ni/Co Cermets
    International Journal of Applied Ceramic Technology, 2016
    Co-Authors: Vikas Verma, B. Venkata Manoj Kumar, Shinhoo Kang
    Abstract:

    © 2016 The American Ceramic SocietyFour compositions of TiCN-WC-Ni/Co Cermets with or without TaC were prepared by pressureless sintering of respective powders, and unlubricated sliding wear behavior against bearing grade steel ball was studied at 5, 10, or 20 N load. Maximum hardness and fracture toughness were obtained for Ti(CN)-5WC-10Ni-10Co-5TaC (in wt%) cermet. With change in the cermet composition and sliding load, coefficient of friction varied from 0.3 to 1.0 and wear rate varied from 3 × 10−7 to 7 × 10−7 mm3/Nm. The increased material transfer and formation of iron oxide-rich tribochemical layer were responsible for the reduction in friction and wear for Ti(CN)-5WC-10Ni-10Co-5TaC cermet.

  • enhanced toughness of titanium carbonitride based Cermets by addition of ti w c carbides
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2016
    Co-Authors: Choongkwon Park, Shinhoo Kang
    Abstract:

    Abstract Ti(CN)-based cermet is a potential alternative to WC–Co for cutting applications. We attempted to improve the mechanical properties of Ti(CN)-based Cermets by adding (Ti 0.88 W 0.12 )C and (Ti 0.88 W 0.12 )(C 0.7 N 0.3 ). The (Ti 0.88 W 0.12 )C phase decreased the number of Ti(CN) cores more effectively than (Ti 0.88 W 0.12 )(C 0.7 N 0.3 ) and thus improved toughness was obtained. The binder phase fractions were altered substantially by the kind of carbides. In particular, the presence of N in (Ti 0.88 W 0.12 )(C 0.7 N 0.3 ) increased the binder fractions and refined the microstructure of Ti(CN) Cermets significantly. However, the increase in the binder faction provided a limited improvement in toughness in the systems of study.

  • 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, 2014
    Co-Authors: Seyed Mahdi Rafiaei, Shinhoo Kang
    Abstract:

    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.

B Manoj V Kumar - One of the best experts on this subject based on the ideXlab platform.

  • tribological characteristics of conventionally sintered ticn wc ni co Cermets against cemented carbide
    Ceramics International, 2017
    Co-Authors: Vikas Verma, B Manoj V Kumar
    Abstract:

    Abstract Present research deals with the tribological behavior of TiCN-WC-Ni/Co Cermets with or without TaC in unlubricated sliding at different loads (5–20 N). Commercially available cemented carbide hard material was selected as counterbody to understand the potential of new generation Cermets in severe conditions of sliding. Dense TiCN based Cermets were processed via conventional sintering whose hardness and fracture toughness varied from 14 to 16 GPa and 8.75–9.25 MPa m1/2, respectively. The size and fraction of adjacent ceramic phase in the microstructure influenced mechanical properties and wear behavior of the Cermets. A variation of 79% in steady state coefficient of friction (COF) and 70% in wear rate is found with respect to composition and load. Hard oxide debris particles are responsible for higher COF at low load, whereas their compaction results in the tribolayer formation at high load. Material transfer from cemented carbide ball onto the cermet disc enhanced at high load due to increased contact temperature. The refined size and least fraction of adjacent ceramic phase are attributed for reduced wear in TaC added TiCN-WC-Ni/Co cermet.

  • crater wear mechanisms of ticn ni wc Cermets during dry machining
    International Journal of Refractory Metals & Hard Materials, 2007
    Co-Authors: B Manoj V Kumar, Ram J Kumar, Bikramjit Basu
    Abstract:

    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.%).

  • electro discharge machining performance of ticn based Cermets
    International Journal of Refractory Metals & Hard Materials, 2007
    Co-Authors: B Manoj V Kumar, Bikramjit Basu, J Ramkumar, Shinhoo Kang
    Abstract:

    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.

Bikramjit Basu - One of the best experts on this subject based on the ideXlab platform.

  • Fretting Wear Properties of TiCN-Ni Cermets: Influence of Load and Secondary Carbide Addition
    Metallurgical and Materials Transactions A, 2008
    Co-Authors: B.v. Manoj Kumar, Bikramjit Basu
    Abstract:

    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.

  • crater wear mechanisms of ticn ni wc Cermets during dry machining
    International Journal of Refractory Metals & Hard Materials, 2007
    Co-Authors: B Manoj V Kumar, Ram J Kumar, Bikramjit Basu
    Abstract:

    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.%).

  • electro discharge machining performance of ticn based Cermets
    International Journal of Refractory Metals & Hard Materials, 2007
    Co-Authors: B Manoj V Kumar, Bikramjit Basu, J Ramkumar, Shinhoo Kang
    Abstract:

    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.

  • Electrochemical Behavior of TiCN–Ni‐Based Cermets
    Journal of the American Ceramic Society, 2006
    Co-Authors: B.v. Manoj Kumar, R. Balasubramaniam, Bikramjit Basu
    Abstract:

    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.

  • densification and properties of transition metal borides based Cermets via spark plasma sintering
    Journal of The European Ceramic Society, 2006
    Co-Authors: T Venkateswaran, Bikramjit Basu, G B Raju
    Abstract:

    Abstract Engineering borides like TiB 2 and ZrB 2 are difficult to sinter materials due to strong covalent bonding, low self-diffusion coefficient and the presence of oxide layer on the powder particles. The present investigation reports the processing of hard, tough and electrically conductive transition metal borides (TiB 2 and ZrB 2 ) based Cermets sintered with 6 wt.% Cu using spark plasma sintering (SPS) route. SPS experiments were carried out with a heating rate of 500 K/min in the temperature range of 1200–1500 °C for a varying holding time of 10–15 min and the optimization of the SPS conditions is established. A maximum density of ∼95% ρ th in ZrB 2 /Cu and ∼99% ρ th in TiB 2 /Cu is obtained after SPS processing at 1500 °C for 15 min. While the optimized TiB 2 /Cu cermet exhibits hardness and fracture toughness of ∼17 GPa and ∼11 MPa m 1/2 , respectively, the optimized ZrB 2 /Cu cermet has higher hardness of ∼19 GPa and fracture toughness of ∼7.5 MPa m 1/2 , respectively. High electrical conductivity of ∼0.20 MΩ −1  cm −1 (TiB 2 /Cu) and ∼0.15 MΩ −1  cm −1 (ZrB 2 /Cu) are also measured with the optimally sintered Cermets.

Hongyu Yang - One of the best experts on this subject based on the ideXlab platform.

  • simultaneously improved strength and toughness of in situ bi phased tib2 ti c n ni Cermets by mo addition
    Journal of Alloys and Compounds, 2020
    Co-Authors: Hongyu Yang, Zheng Wang, Peijie Ji
    Abstract:

    Abstract Optimizing strength and toughness are always the key issues for cutter materials. Generally, increasing the strength of the material would sacrifice its toughness or vice versa. In this work, the TiB2–Ti(C,N)-(Ni + Mo) Cermets with high strength and high toughness were fabricated in Mo–Ni–B4C-Ti-BN systems by reactive hot pressing. With the addition of Mo, the highest combustion temperature decreased and the matching degree between ceramic particles and Ni binder was improved, which lead to the decrease in the porosity of Cermets and the refinement of ceramic particles. The fabricated TiB2–Ti(C,N)–Ni cermet with 2 wt.% Mo addition exhibited the simultaneously improved strength and toughness. The σUCS and KIC of the TiB2– Ti(C,N)-(Ni+2Mo) cermet were 3.24 GPa and 7.28 MPa·m1/2 respectively, which were increased by 11% and 20% compared with those of the cermet without Mo addition. The strengthening mechanisms of the Cermets with Mo addition were attributed to the refinement of ceramic particles, the improved homogeneity in the microstructure and the simultaneously increase in the strength of interfacial bonding and the binder itself.

  • effect of ta addition on the microstructures and mechanical properties of in situ bi phase tib2 ticxny ni ta Cermets
    Ceramics International, 2019
    Co-Authors: Hongyu Yang, Zheng Wang, Jianbang Lu
    Abstract:

    Abstract In this work, in situ bi-phase (TiB2-TiCxNy)/(Ni-Ta) Cermets were fabricated via a combined combustion synthesis and hot-pressing (CSHP) method in a Ni-Ti-BN-B4C-Ta system. The effects of Ta addition on the reaction process, phase constituents, microstructures and mechanical properties of the (TiB2-TiCxNy)/(Ni-Ta) Cermets were studied. Ta is shown to dilute the system and lead to a small number of intermediate phases (Ni20Ti3B6 and Ni3Ti) that are retained in the products. Furthermore, the addition of Ta can markedly refine the ceramic particles and decrease the size and quantity of voids. The evaluation of the mechanical properties revealed that an increase in the Ta content resulted in increases in the compression strength (σUCS) and hardness and that the fracture strain (ef) increased first and then decreased. The cermet with the optimal addition of 5 wt% Ta possessed the best mechanical properties without decreasing the value of ef (2.9%). The addition of 5 wt% Ta resulted in a compressive strength of 3.37 GPa and the highest hardness of 1909 Hv, which is an increase of ~16% and ~22%, respectively, compared to Cermets without added Ta.

Jinwen Ye - One of the best experts on this subject based on the ideXlab platform.

  • the fabrication of multi core structure Cermets based on ti w ta cn and ticn solid solution powders
    International Journal of Refractory Metals & Hard Materials, 2017
    Co-Authors: Jie Wang, Jinwen Ye, Jia Pang
    Abstract:

    Abstract A novel multi-core structure Cermets consisted of both black-core/rim structure and grey-core/rim structure were obtained by partially replacing TiCN powder with (Ti,20W,15Ta)CN powder via low-pressure sintering process. The toughness and strength of TiCN-based Cermets were optimized and its feature of high hardness was maintained simultaneously. Systematically, it was investigated that the influences of various weight ratios of both (Ti,20W,15Ta)CN/TiCN and Co/Ni on the microstructure and mechanical properties of the multi-core Cermets. The results showed that the addition of (Ti,20W,15Ta)CN powder could cause the refinement of the core size and the occurrence of the secondary phase (W,Mo,Ti) 3 + x (Co,Ni) 3 − x C (0  IC ) of the Cermets while increasing the (Ti,20W,15Ta)CN content. The optimal comprehensive mechanical performance was found in cermet M60 with transverse rupture strength (TRS) of 1903.32 MPa, Vickers hardness (HV 30 ) of 16.33 GPa and fracture toughness of 12.19 MPa·m 1/2 .

  • early high temperature oxidation behavior of ti c n based Cermets with multi component alcocrfeni high entropy alloy binder
    International Journal of Refractory Metals & Hard Materials, 2014
    Co-Authors: Jinwen Ye
    Abstract:

    Abstract The early high-temperature oxidation behavior of Ti(C,N)-based Cermets with equiatomic AlCoCrFeNi high-entropy alloy binder has been studied, as well as the cermet with Ni/Co binder as a reference. Experiments were performed at the temperature range of 800–1100 °C in static laboratory air. The micro-structural evolution of the multi-layered oxide scales on the Cermets was investigated and the effect of binder phase constituent on the oxidation characteristics of Ti(C,N)-based Cermets was evaluated. The results demonstrated that the cermet with AlCoCrFeNi multi-element alloy binder possesses superior oxidation resistance, which is greatly better than that of the cermet with Ni/Co metallic binder under the same condition. We suggest that the formation of a continuous and dense external oxide scale can effectively impede the outward diffusion of volatile tungsten oxides and inward oxygen transport, leading to a remarkable improvement of oxidation resistance. In addition, the enhanced oxidation resistance was related to the high Cr and Al concentration in AlCoCrFeNi binder phase that urges the formation of oxide layers with more efficient passivation effect against oxidation.

  • effect of secondary carbides addition on the microstructure and mechanical properties of ti w mo v c n based Cermets
    International Journal of Refractory Metals & Hard Materials, 2011
    Co-Authors: Haijun Yu, Jinwen Ye
    Abstract:

    Abstract (Ti, W, Mo, V)(C, N)-based Cermets were prepared by mixing Mo2C, WC and TaC with ultrafine (Ti, W, Mo, V)(C, N) powders, and then processed via a conventional P/M technique. The effect of Mo2C, WC and TaC on the microstructure and mechanical properties of (Ti, W, Mo, V)(C, N)–8 wt.% Ni–7 wt.% Co systems was investigated. The Mo2C content was varied from 0 to 10 wt.% and additive WC or TaC was added at a level of 5 wt.% with Mo2C addition. The results show that the densification of (Ti, W, Mo, V)(C, N)–8 wt.% Ni–7 wt.% Co Cermets was improved significantly by the addition of Mo2C. With the increase of Mo2C content, there is a coarsening tendency in the microstructure of (Ti, 20W, 15Mo, 0.2V)(C, N)–8Ni–7Co system, but the refinement for (Ti, 15W, 5Mo, 0.2V)(C, N)–8Ni–7Co. TaC addition decreases the density of (Ti, 15W, 5Mo, 0.2V)(C, N)–10Mo2C–8Ni–7Co cermet and thus weakens its bending strength. (Ti, 15W, 5Mo, 0.2V)(C, N)–10Mo2C–5WC–8Ni–7Co cermet has optimal mechanical properties: bending strength of 1999 MPa, hardness (Hv) of 1677 MPa and toughness of 9.95 MPa m1/2 respectively by adding WC, which is due to its ultrafine and weak core/rim structure.