The influence of (Ti,W)C and NbC on the mechanical behavior of alumina

Acchar, Wilson; Cairo, Carlos Alberto Alves

doi:10.1590/s1516-14392006000200011

Cited by 20 publications

(7 citation statements)

References 15 publications

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“…W wyniku modyfikacji mikrostruktury ceramiki, przez wprowadzenie do niej drugiej fazy z tlenku glinu, zmieniają się właściwości użytkowe materiału (wytrzymałość mechaniczna czy odporność na nagłe zmiany temperatury). Na podstawie badań stwierdzono, że kompozyty ceramiczne, w których osnowa z tlenku glinu jest dyspersyjnie wzmacniana fazą ceramiczną w postaci TiC, TiN, ZrO 2 , WC, NbC, Ti(C,N), SiC czy TiB 2 , charakteryzują się wysoką twardością, odpornością na zużycie i obojętnością chemiczną oraz wykazują wyższą wytrzymałość mechaniczną i odporność na pękanie w porównaniu z tlenkiem glinu [4][5][6].…”

Section: Materiały I Metodyka Badańunclassified

Mechanical properties of titanium carbonitride reinforced alumina tool composites

Szutkowska¹,

Boniecki

Podsiadło³

et al. 2018

Mechanik

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The present study reports mechanical properties obtained by reinforcing alumina composites with Ti(C,N) in amount 30 wt.% prepared on the basis micro and nanoscale trade powders. The pressureless sintering PS in a vacuum and SPS method of sintering were used. Vickers hardness, density, Young modulus, wear resistance were evaluated. Fracture toughness (KIC) at ambient and elevated temperatures up to 1073 K, characteristic for tool work was measured. Physical and mechanical properties of the composites Al2O3/Ti(C,N)/ZrO2 based on the powders in microscale were compared with composites containing nanoscale powders in a range from 17 to 36 wt.%. Tested composites with nanoscale powders content reveal lower KIC (approx. 10÷30%) at ambient temperature in comparison to composites based on powders in microscale. However, in the elevated temperatures their fracture toughness increases up to 30%. The observation of the microstructure of tested composites was carried out using scanning electron microscopy.

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Section: Materiały I Metodyka Badańunclassified

Mechanical properties of titanium carbonitride reinforced alumina tool composites

Szutkowska¹,

Boniecki

Podsiadło³

et al. 2018

Mechanik

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“…To compute K th , the properties of the oxide or oxides formed at the crack tip are required to assess oxidation-induced transformation toughening. The crystal structure, lattice parameters, Young's modulus (E ox ), and fracture toughness (K ox ), for selected oxides, carbides, and intermetallics are compiled from the literature, [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] and the results are presented in Table II. Using information shown in Table II, relevant crack-tip oxidation reactions that may lead to transformation toughening in Ni-base superalloys are identified.…”

Section: Model Applicationsmentioning

confidence: 99%

“…From Eq. [20], it is obvious that material [48] 41.61 200 [71] 96 to 131 [70] NbC Fcc a o = 4.470 [51,52] 93.91 340 to 400 [54] 3.0 to 4.0 [54] Cubic a o = 10.63 [51,53] 1201.2 325 to 334 [57] 7.1 [56] Ni 3 Al Cubic a o = 3.57 to 3.60 [48][49][50] 45.5 178 [58] 30 [ [64] 257.59 362 [54,59,60] 3.5 [54,59,60] TiO 2 tetragonal a o = 3.784; c o = 9.514 [65] 136.27 270.7 [59,60] 2.49 [59,60] …”

Section: ½20mentioning

confidence: 99%

Time-Dependent Crack Growth Thresholds of Ni-Base Superalloys

Chan

2014

Metall Mater Trans A

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A micromechanical model has been developed for predicting the time-dependent crack growth threshold and its variability by considering oxide formation or cavity formation ahead of an elastic crack subjected to a sustained load at a stress intensity factor, K, at elevated temperatures in air. It is demonstrated that stress relaxation associated with a volume-expansion process such as the formation of creep cavities or oxides with a positive transformation strain can induce residual stresses at the tip of the elastic crack. The near-tip residual stresses must be overcome by the external load, thereby instigating a growth threshold, K th , for the onset of time-dependent crack growth. This micromechanical framework provides the basis for developing appropriate predictive models for the time-dependent crack growth thresholds associated with several damage processes, including (1) oxidation-assisted intergranular crack growth, (2) K-controlled creep crack growth along an intergranular path, and (3) stress corrosion cracking. The micromechanical threshold models have been utilized to predict the time-dependent crack growth thresholds of a variety of Ni-base superalloys. The material parameters that contribute to the variability of the time-dependent crack growth thresholds have been identified and related to variations of mixed oxides or creep cavities formed near the crack tip. A size scale effect is also predicted for the transformation toughening phenomenon, which is largest at or below K th but diminishes at increasing K levels above the threshold. Finally, the micromechanical models are utilized to identify means for suppressing time-dependent crack growth in Ni-base alloys.

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“…Ceramic matrix composites (CMCs) are systems designed to combine the excellent strength and high temperature properties of ceramics with the durability of advanced composites [3][4][5]. Ceramic composites in which the alumina matrix is reinforced with a wide range of ceramic phases including TiC, TiN, ZrO 2 , WC, NbC, Ti(C,N), SiC, TiB 2 , offer good strength properties, high hardness, wear resistance, chemical inertness and an improved toughness level in comparison to alumina [6][7][8]. The current interest in transition-metal carbides and nitrides is due to the many unique properties that these compounds exhibit.…”

Section: Introductionmentioning

confidence: 99%

Properties of TiC and TiN Reinforced Alumina–Zirconia Composites Sintered with Spark Plasma Technique

Szutkowska

Cygan

Podsiadło

et al. 2019

Metals

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In this paper, Al2O3–ZrO2 composites with an addition of 20 wt% TiN and 10 wt% TiC were modified. The addition of zirconia in a range from 2 to 5 wt% of the monoclinic phase and 10 wt% of Y2O3 stabilised ZrO2 affected the mechanical properties of the composites. A new type of sintering technique—the spark plasma sintering (SPS) method—within a temperature range from 1575 °C to 1675 °C, was used. Vickers hardness, apparent density, wear resistance and indentation fracture toughness KIC(HV) were evaluated at room temperature. An increase of the sintering temperature resulted in an improvement of Vickers hardness and an increase of the fracture toughness of the tested composites. The tribological properties of the samples were tested using the ball-on-disc method. The friction coefficient was in a range from 0.31 to 0.55, depending on the sintering temperature. An enhancement of the specific wear rate was dependent on the sintering temperature. The mechanical properties of the samples sintered by pressureless sintering (PS) were compared. X-ray diffraction patterns were presented in order to determine the phase composition. SEM microstructure of the tested composites sintered at different temperatures was observed.

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The influence of (Ti,W)C and NbC on the mechanical behavior of alumina

Cited by 20 publications

References 15 publications

Mechanical properties of titanium carbonitride reinforced alumina tool composites

Mechanical properties of titanium carbonitride reinforced alumina tool composites

Time-Dependent Crack Growth Thresholds of Ni-Base Superalloys

Properties of TiC and TiN Reinforced Alumina–Zirconia Composites Sintered with Spark Plasma Technique

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