Crack-Resistance Curve and Cyclic Fatigue in Ceramic Materials

Mai, Yiu‐Wing; Hu, Xiaozhi; Duan, Kai; Cotterell, B.

doi:10.1007/978-1-4615-3350-4_27

Cited by 10 publications

(4 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…High dispersion of the fatigue results for stress levels of 570, 610 and 650 MPa can be observed in Fig. 4, which is the ubiquitous behaviour of ceramic materials [23,27,28,38,39]. The statistical analysis reflects this behaviour at stresses above the material's fatigue limit.…”

Section: Statistical Analysis Of Fatiguementioning

confidence: 79%

“…In the case of surface microcracks generated by the hydrothermal degradation or during polishing of the 3Y-TZP samples, these phases are present on the material's tensile surface in the 4-point bending fatigue test. The maximum bending stresses used in the tests, and the constant and cyclical stress variations characteristic for the fatigue test, lead to subcritical crack growth [26,[37][38][39], especially under larger amplitudes. It seems possible that there is a considerable population of microcrack defects present in the critical area in the 4-point tests (Fig.…”

Section: Fatigue Behaviourmentioning

confidence: 99%

See 1 more Smart Citation

Cyclic fatigue behaviour of hydrothermally aged 3Y-TZP ceramics in 4-point bending tests

Souza

Duarte

Alves

et al. 2021

PAC

View full text Add to dashboard Cite

Fatigue is one of the most important properties to be considered in ceramic dental implants due to cyclic mechanical stresses arising from the chewing process. In this work, the fatigue behaviour of hydrothermally degraded ZrO2-based ceramics stabilized with 3mol% Y2O3 (3Y-TZP) was studied in 4-point bending tests. Samples of 3Y-TZP were compacted (100MPa), sintered at 1475 ?C for 2 h, polished and hydrothermally degraded in an autoclave as described in the ISO-13356 standard. The samples were characterized by their relative density, crystalline phase composition, microstructure and surface roughness. The highly dense (>99.6%TD) sintered 3Y-TZP ceramics has only tetragonal t-ZrO2 phase, even after hydrothermal ageing. Furthermore, the ceramic materials presented a Vickers hardness of 12.7?0.2GPa, a fracture toughness of 7.1?0.3MPa?m1/2 and a 4-point bending strength of 940.1?67MPa. Based on the bending test results 5 different stress levels for the fatigue tests were selected and conducted by cyclic 4-point bending obtaining the S-N curve. Weibull statistics was used for the statistical analysis. The fatigue tests indicate that the limit of fatigue resistance of this 3Y-TZP ceramics is around 550MPa, i.e. higher than the limits established in the ISO-13356 standard for the use of Y-TZP ceramics for the manufacture of implants. The fatigue behaviour of the investigated 3Y-TZP ceramics was related to the toughening mechanisms acting in Y-TZP ceramics, such as transformation toughening related to t?m phase transformation and microcracking.

show abstract

Section: Statistical Analysis Of Fatiguementioning

confidence: 79%

Section: Fatigue Behaviourmentioning

confidence: 99%

Cyclic fatigue behaviour of hydrothermally aged 3Y-TZP ceramics in 4-point bending tests

Souza

Duarte

Alves

et al. 2021

PAC

View full text Add to dashboard Cite

show abstract

“…One of the authors has investigated fatigue crack growth and the R-curve for polycrystalline magnesia and demonstrated that the crack growth characteristics are controlled by the shielding effects in the wake of the crack tip. The shielding effects are reduced by cyclic loading which promotes fretting damage in the wake region [5,9,10]. Assuming that the shielding effects in the wake are completely reduced by cyclic loading and that the fracture mechanism except the fretting behaviour is the same under monotonic and cyclic loadings, Kth represents the minimum fracture resistance of an ideal crack, which corresponds to the essential definition of K,, .…”

Section: Discussionmentioning

confidence: 99%

Fatigue Crack Growth Behaviour and Fracture Resistance in Ceramics

Ogawa

Ochi

Tokaji

1993

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

Fatigue crack growth and the fracture resistance curve (R-curve) were investigated in a polycrystalline alumina (AD90) and a silicon carbide whisker-reinforced alumina composite (Al,O,-SiC,) at room temperature in air using a combined loading technique for stabilizing crack growth, and a surface film technique for monitoring crack length. Fatigue crack growth was evaluated successfully with those experimental techniques. Load shedding tests were performed until the crack became dormant, in order to determine the threshold stress intensity factor Kth. Subsequently, the specimens were used for quasi-static crack growth tests under a monotonic loading condition. The R-curves were determined in this experiment; however, fracture resistance did not increase markedly with crack growth. Detailed observations of the crack growth behaviour revealed that the flat R-curve was attributed to the shielding effect of the fatigue crack tip wake. Thus, the fatigue precrack introduced by the load shedding test was not regarded as an ideal crack for determining the R-curve. Fractographic observations were performed to investigate the mechanistic difference between fatigue and quasi-static crack growth. It was found that the cyclic loading produced fretting damage in the wake region and it reduced the shielding effect of the fatigue cracks. Based on the experimental results, the relationship between the fatigue crack growth and the R-curve is discussed as is the significance of Kth as a material parameter. NOMENCLATURE a =crack length a, =notch length a,, = crack length when Kth is achieved B = specimen thickness E = Young's modulus COD = crack opening displacement da/dt =crack growth rate with time da/dN = crack growth rate with cycles H = specimen height K = stress intensity factor Kf, =fatigue fracture toughness at which fatigue crack growth becomes unstable K,, = fracture toughness K,,, = maximum stress intensity factor K,,, = minimum stress intensity factor K , = fracture toughness with maximum shielding effect K,h =threshold stress intensity factor 1 = distance from the tensile load line to the compressive load line m, C =Paris law constants N = number of cycles P, = compressive load applied to the ligament of specimen W = specimen width Aa = crack extension us = tensile strength oc = compressive strength uF = flexure strength P,,, = maximum tensile load applied at the loading holes 837 838 TAKESHI OCAWA et at.

show abstract

“…As relações entre os mecanismos que aumentam a tenacidade à fratura e mecanismos de fadiga cíclica vêm sendo discutidas, desde os anos 90. (GRATHWOHL, 1991;GRATHWOHL, 1992;MAI, 1992 Para ensaio de determinação de módulo de flexão, aplica-se a carga crescente, monotonicamente, até à fratura; já no ensaio de fadiga, é selecionada uma carga que corresponde à tensão desejada. Como explicado na teoria de resistência dos materiais, para o caso em tela a tensão normal máxima ocorrerá na superfície tracionada (inferior), numa região de momento fletor máximo, o que é dado pela Equação 2.21.…”

Section: Resistência à Fadiga De Materiais Cerâmicosunclassified

Cerâmicas dentárias à base de ZrO2, aditivadas com biovidro: processamento, caracterização estrutural e mecânica

Bicalho¹

View full text Add to dashboard Cite

Crack-Resistance Curve and Cyclic Fatigue in Ceramic Materials

Cited by 10 publications

References 50 publications

Cyclic fatigue behaviour of hydrothermally aged 3Y-TZP ceramics in 4-point bending tests

Cyclic fatigue behaviour of hydrothermally aged 3Y-TZP ceramics in 4-point bending tests

Fatigue Crack Growth Behaviour and Fracture Resistance in Ceramics

Cerâmicas dentárias à base de ZrO2, aditivadas com biovidro: processamento, caracterização estrutural e mecânica

Contact Info

Product

Resources

About