Gradient zones in WC–Ti(C,N)–Co-based cemented carbides: experimental study and computer simulations

Ekroth, Malin; Frykholm, Robert; Lindholm, M.; Andrén, Hans-Olof; Ågren, John

doi:10.1016/s1359-6454(00)00029-x

Cited by 117 publications

(43 citation statements)

References 6 publications

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“…These local defects, attributed to the existence of cracks, to incomplete bonding between particles, and to interconnected porosity create direct paths through which the corrosive medium can gain access to the substrate material. Nitridation is an alternative method for controlling the chemical composition and microstructure at the surface of the hardmetal in order to improve its wear resistance [24][25][26][27][28][29][30][31][32][33][34][35]. By nitriding Ti-containing hardmetals a Ti(C,N) binder-free surface can be formed.…”

Section: Introductionmentioning

confidence: 99%

Influence of binder metal and surface treatment on the corrosion resistance of (W,Ti)C-based hardmetals

Barbatti

Sket

García³

et al. 2006

Surface and Coatings Technology

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The effect of a nitridation surface treatment on the microstructure and corrosion resistance of Co and Ni-binder (W,Ti)C-based hardmetals with additions of (Ta,Nb)C was investigated. Nitridation treatment produces a surface layer with a higher hard phase (Ti,Ta,Nb,W)(C,N) content. The near-surface layer thickness and microstructure are affected by the choice of binder (Co respectively Ni). The corrosion resistance of the hardmetals was characterized using linear sweep voltammetry. The microstructure of the hardmetals was determined before and after corrosive attack by optical microscopy and SEM. The results of the corrosion tests and microstructure analyses are interpreted in terms of the correlation between the hardmetal morphology and porosity and ion transport through the interface binder-electrolyte. The nitridation treatment of the hardmetals strongly increases the resistance to aggressive corrosion media for hardmetals both with Co and Ni-binder phase and thus may positively influence the hardmetal lifetime in cutting applications in chemically aggressive environments.

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Section: Introductionmentioning

confidence: 99%

Influence of binder metal and surface treatment on the corrosion resistance of (W,Ti)C-based hardmetals

Barbatti

Sket

García³

et al. 2006

Surface and Coatings Technology

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“…The graded cemented carbide owns high surface toughness, so it is suitable for coating substrate. Afterward, Schwarzkopf, Gustafson, and Ekroth et al made further investigation on the formation mechanism and growth kinetics of CCFL [10][11][12] and developed an N-Ti coupling diffusion model to explain the formation process of CCFL. Their model suggested that if cemented carbides containing cubic phases, such as Ti(C,N) or (Ti,W)(C,N), were sintered under a nitrogen free atmosphere, e.g., in vacuum, an outward nitrogen diffusion would be created because of the difference in nitrogen activity between the surface zone and the core zone of the substrate.…”

Section: Introductionmentioning

confidence: 99%

Growth kinetics of cubic carbide free layers in graded cemented carbides

Shi

Liu

Huang

et al. 2012

Int J Miner Metall Mater

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In order to reveal the formation mechanism of cubic carbide free layers (CCFL), graded cemented carbides with CCFL in the surface zone were fabricated by a one-step sintering procedure in vacuum, and the analysis on microstructure and element distribution were performed by scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA), respectively. A new physical model and kinetic equation were established based on experimental results. Being different from previous models, this model suggests that nitrogen diffusion outward is only considered as an induction factor, and the diffusion of titanium through liquid phase plays a dominative role. The driving force of diffusion is expressed as the differential value between nitrogen partial pressure and nitrogen equilibrium pressure essentially. Simulation results by the kinetic equation are in good agreement with experimental values, and the effect of process parameters on the growth kinetics of CCFL can also be explained reasonably by the current model.

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“…Gradient cemented carbides were fabricated according to the two-step sintering procedure in many former literatures [6][7][8][9]. In Ref.…”

Section: Introductionmentioning

confidence: 99%

Effect of nitrogen introduction methods on the microstructure and properties of gradient cemented carbides

Yang

Xiong

Sun

et al. 2011

Int J Miner Metall Mater

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Gradient cemented carbides with the surface depleted in cubic phases were prepared following normal powder metallurgical procedures. Gradient zone formation and the influence of nitrogen introduction methods on the microstructure and performance of the alloys were investigated. The results show that the simple one-step vacuum sintering technique is doable for producing gradient cemented carbides. Gradient structure formation is attributed to the gradient in nitrogen activity during sintering, but is independent from nitrogen introduced methods. A uniform carbon distribution is found throughout the materials. Moreover, the transverse rupture strength of the cemented carbides can be increased by a gradient layer. Different nitrogen carriers give the alloys distinguishing microstructure and mechanical properties, and a gradient alloy with ultrafine-TiC 0.5 N 0.5 is found optimal.

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Gradient zones in WC–Ti(C,N)–Co-based cemented carbides: experimental study and computer simulations

Cited by 117 publications

References 6 publications

Influence of binder metal and surface treatment on the corrosion resistance of (W,Ti)C-based hardmetals

Influence of binder metal and surface treatment on the corrosion resistance of (W,Ti)C-based hardmetals

Growth kinetics of cubic carbide free layers in graded cemented carbides

Effect of nitrogen introduction methods on the microstructure and properties of gradient cemented carbides

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